Tag /

Obesity

Episodes

exercise

Dr. Layne Norton on Building Muscle – Insights on Diet, Training, and Supplements

Posted on August 26th 2024 (9 months)

Dr. Layne Norton and I discuss fat loss, resistance training, seed oils, the carnivore diet, artificial sweeteners, and much more.

rhonda
Premium

Q&A #35 with Dr. Rhonda Patrick (4/30/2022)

Posted on April 30th 2022 (about 3 years)

Dr. Rhonda Patrick answers audience questions on various health, nutrition, and science topics in this Q&A session.

fasting

Do healthy people benefit from intermittent fasting? | Dr. Mark Mattson

Posted on April 2nd 2022 (about 3 years)

In this clip, Dr. Mark Mattson predicts that intermittent fasting benefits both overweight and healthy weight people.

Topic Pages

  • Blood-brain barrier

    The blood-brain barrier allows the passage of nutrients and cell signals from the bloodstream to the brain while excluding harmful substances.

  • Fasting

    Fasting – the voluntary abstinence from food and drink – is an ancient practice now widely appreciated for its beneficial effects on healthspan.

  • Nicotinamide mononucleotide

    Nicotinamide mononucleotide is a precursor of NAD+, a coenzyme necessary for cellular energy production and DNA repair. It is available as a supplement.

  • Nicotinamide riboside

    Nicotinamide riboside is a precursor of NAD+, a coenzyme necessary for energy production and cellular repair. It is available from food and supplements.

  • Sodium (Salt)

    Sodium plays a crucial role in human physiology, yet its consumption remains a topic of ongoing debate in health and nutrition science.

  • Sugar-sweetened beverages (SSBs)

    Sugar-sweetened beverages such as soda, juice, and sports drinks provide large doses of rapidly absorbable sugar, posing a unique risk to health.

  • Ultra-processed Foods (UPFs)

    UPFs are formulations of mostly cheap industrial sources of dietary energy (calories) and nutrients plus additives that have negative effects on human health.

News & Publications

  • Exercise doesn't just release vitamin D from fat stores—it potentially alters the hormone's metabolism and offers a route to restore vitamin D availability in obesity, where supplementation often falls short. www.technologynetworks.com
    Vitamin D Exercise Obesity

    Vitamin D, a fat-soluble nutrient, is sequestered in adipose tissue, limiting its circulation—an effect amplified in obesity. Obese adults, for example, exhibit a 57 % smaller rise in circulating vitamin D₃ after whole-body ultraviolet exposure and are more than half as likely to reach sufficient vitamin D levels than normal-weight adults. Against this backdrop, the VitaDEx randomized trial showed that ten weeks of indoor exercise during winter sharply attenuated seasonal vitamin D loss and fully preserved its active hormone, 1,25(OH)₂D₃—without weight loss or supplementation.

    • Active hormone maintained: Exercise fully prevented the winter decline in 1,25(OH)₂D₃, while controls experienced a 15 % drop. (The precursor 25-hydroxy-vitamin D fell only 15 % in exercisers versus 25 % in sedentary controls.)
    • Adipose sequestration puzzle: Contrary to expectations, adipose vitamin D concentrations remained largely unchanged. “Exercise did not drive a greater decrease in adipose tissue concentrations of vitamin D…there was no correlation between the change in serum 25(OH)D and changes in adipose vitamin D₃ concentrations.”
    • Mechanistic pivot: Researchers suggested possible transient vitamin D mobilization, depot-specific effects, or direct metabolic adaptations improving vitamin D efficiency. They speculated that regular physical activity might enable “more ‘efficient’ vitamin D metabolism, making better use of the available substrate to generate the active metabolite without tipping the balance into a negative feedback loop.”

    Taken together, the findings indicate exercise is not merely releasing vitamin D from fat stores; it is altering the flux and enzymatic handling of the hormone, offering a route to restore endocrine availability where supplementation often fails in obesity.

    Press Release: Regular Exercise Helps Maintain Vitamin D Levels During Winter
    Study: Exercise without Weight Loss Prevents Seasonal Decline in Vitamin D Metabolites: The VitaDEx Randomized Controlled Trial

    Read more
  • Artificial sweetener sucralose may disrupt the brain's appetite regulation by mimicking sweetness without increasing blood sugar, leading to increased hunger and altered brain activity. www.nature.com
    Brain Diet Obesity Sugar Weight Loss

    Artificial sweeteners like sucralose are marketed as healthier alternatives to sugar, but they may send mixed signals to the brain. A recent study found that sucralose increased hunger and altered activity in the part of the brain that regulates appetite, with effects differing by body weight.

    Researchers asked 75 young adults—some with a healthy weight and some with overweight or obesity—to drink a beverage sweetened with either sucralose (often marketed as Splenda), sucrose (table sugar), or plain water on three separate occasions. Afterward, the researchers measured the participants' blood glucose levels, collected their self-reported hunger ratings, and conducted brain scans to examine activity and connectivity in key regions involved in appetite control.

    Compared to sugar, sucralose increased blood flow to the hypothalamus and promoted stronger feelings of hunger. Sucralose also heightened hypothalamic activity more than water but didn’t influence hunger. Only sugar elevated blood glucose levels, an increase linked to reduced activity in the hunger-regulating regions of the brain.

    Interestingly, the brain’s response to sucralose differed based on body weight: In people with a healthy weight, sucralose enhanced connections between the hypothalamus and areas involved in attention and decision-making. In those with overweight, sucralose diminished connections to brain regions that process bodily sensations. And those with obesity exhibited little to no change in these neural connections. Compared to water, both sweeteners elicited distinct patterns of brain activity depending on weight status.

    These findings suggest that sucralose interferes with the brain’s normal appetite-regulating signals by mimicking sweetness without delivering the expected rise in blood sugar. This mismatch appears to increase hunger and alter brain connectivity in ways that vary depending on body weight. Artificial sweeteners also affect the gut microbiome. Learn more in this clip featuring Dr. Eran Elinav.

    Read more
  • Intermittent fasting three nonconsecutive days per week coupled with regular exercise promotes more weight loss than daily calorie restriction. www.acpjournals.org
    Diet Obesity Fasting Weight Loss

    Diets that require daily calorie cutting are hard to adhere to, and most people gain the weight back within a year. Intermittent fasting, which involves eating very little on some days and freely on others, might offer a more sustainable alternative. A recent study found that fasting three nonconsecutive days per week promoted more weight loss than daily calorie restriction as part of a comprehensive weight loss program.

    Researchers assigned 165 adults aged 18 to 60 with a body mass index between 27 and 46 to one of two diet plans. One group followed a 4:3 intermittent fasting schedule, eating freely on four days of the week and cutting calories by 80% on three nonconsecutive days each week. The second group followed a daily calorie restriction (about 34% less than baseline needs) to match the same total weekly calorie reduction. Both groups also participated in a year-long behavioral weight loss program that included group support and a goal of 300 minutes of moderate exercise weekly.

    After 12 months, participants in the intermittent fasting group lost roughly 6.4 pounds more, on average, than those in the daily calorie restriction group. Just over three-fourths of participants completed the study. The difference in weight loss between the two groups was small but statistically meaningful.

    These findings suggest that intermittent fasting offers a modest advantage over daily calorie restriction for people trying to lose weight, especially when paired with regular exercise and behavioral support. Learn more about the health benefits of intermittent fasting in this clip featuring Dr. Mark Mattson.

    Read more
  • Sleep disruption reduces the newly discovered hormone 'raptin,' potentially increasing appetite and promoting weight gain. www.nature.com
    Diet Obesity Sleep Hormones

    Sleepless nights don’t just leave you tired—they may also interfere with your body’s ability to regulate hunger. Researchers have long known that poor sleep increases the risk of obesity, but the biological link has remained elusive. A recent study found that a sleep-triggered hormone called raptin helps control appetite and may explain why people who don’t get enough sleep are more likely to gain weight.

    Researchers examined brain activity, hormone levels, and eating behavior under different sleep conditions in mice and humans. They identified a previously unknown hormone, which they named raptin, and tracked where and when it was released. They also studied the effects of a genetic variant that blocks raptin production and examined hormone levels in people with sleep deficiency, obesity, and nighttime eating syndrome.

    They discovered that raptin is produced in a part of the brain that regulates hunger and hormone secretion and is released during sleep. When sleep is disrupted, raptin levels drop. In lab experiments, raptin acted on specific receptors in the brain and stomach to reduce appetite and slow stomach emptying. People with obesity and sleep deficiency had lower levels of raptin, while those who underwent therapy to improve sleep showed increases in the hormone. A genetic variant that blocks raptin production was linked to night-time overeating and obesity.

    These findings indicate that raptin explains how sleep influences weight gain and appetite. Learn more about the effects of sleep deprivation in Aliquot #27: Health consequences of sleep deprivation, part I: Metabolic & immune health and Aliquot #28: Health consequences of sleep deprivation, Part 2: Mental & cognitive health

    Read more
  • Poor cardiorespiratory fitness may double the risk of early death, regardless of body weight. bjsm.bmj.com
    Exercise Obesity Cardiovascular

    How fit you are may matter more than how much you weigh when it comes to your risk of dying early. A recent review and meta-analysis found that poor cardiorespiratory fitness increases the risk of early death from cardiovascular disease and other causes, regardless of body weight.

    Researchers analyzed the findings of 20 studies investigating the effects of cardiorespiratory fitness and body weight on the rates of early death from cardiovascular disease and all other causes. The various studies included nearly 400,000 participants and compared the risks among people who were overweight or obese to those who were normal weight.

    They found that overweight, fit people were about 50% more likely to die from cardiovascular disease and had roughly the same overall risk of early death as those with normal weight. Obese, fit people were 62% more likely to die from cardiovascular disease and had an 11% higher overall risk of early death, but these differences were not statistically significant.

    However, being unfit was linked to a much higher risk of death. Normal-weight people who were unfit were about twice as likely to die from cardiovascular disease and all causes. Overweight, unfit people had roughly 2.5 times the risk of cardiovascular death and 82% higher overall risk of early death. Obese, unfit people had more than triple the risk of cardiovascular death and twice the risk of dying from any cause compared to those with normal weight.

    These findings suggest that cardiorespiratory fitness robustly predicts the risk of early death from cardiovascular disease and other causes. Vigorous exercise, such as high-intensity interval training, is a great way to boost cardiorespiratory fitness and prevent early death. Learn more in this episode featuring Dr. Rhonda Patrick.

    Read more
  • The brain's vagus nerve controls fat absorption in the intestine—a possible pathway for managing obesity. pubmed.ncbi.nlm.nih.gov
    Brain Diet Obesity Fat Isothiocyanates

    Fat is a vital energy source, but when consumed in excess, it can promote obesity. However, the amount of fat the body absorbs may be more related to the brain than the gut. A recent study in mice found that signals from the brain’s vagus nerve regulate fat uptake in the intestine, offering a potential means to moderate obesity.

    Researchers manipulated the dorsal motor nucleus of the vagus (DMV), which plays a crucial role in digestion. They inactivated DMV neurons that connect to the jejunum (the middle portion of the intestine), shortening the length of the microvilli in the gut and reducing fat absorption. However, stimulating DMV neurons increased fat absorption and promoted weight gain. Finally, they injected mice with puerarin, a bioactive compound derived from the kudzu plant, and found that the compound mimicked the effect of DMV suppression, further reducing fat absorption.

    These findings suggest that controlling the DMV-vagus-jejunum pathway could provide a novel approach to managing fat absorption and weight. They also highlight yet another way the brain-gut axis influences human health.

    Puerarin is an isothiocyanate, a class of sulfur-containing compounds known for their potent anti-inflammatory, anti-cancer, and anti-obesity effects. Sulforaphane, another well-known isothiocyanate, shares many of these beneficial properties. To learn more about the health effects of sulforaphane, check out our overview article.

    Read more
  • High-protein, low-calorie diets—whether animal or plant-based—lead to an average weight loss of ~18 pounds and improved glucose metabolism in people at risk for type 2 diabetes. dom-pubs.pericles-prod.literatumonline.com
    Diet Obesity Diabetes Muscle Protein Weight Loss

    The global obesity epidemic is driving a marked increase in the incidence of type 2 diabetes, and some experts estimate that by 2024, more than 780 million adults worldwide will develop the disease. A recent study found that high-protein, low-calorie diets promote weight loss and improve cardiometabolic markers in people at risk for type 2 diabetes.

    The study involved 117 adults with either prediabetes or type 2 diabetes and a body mass index (BMI) over 27.5—considered overweight or obese. Participants consumed an animal- or plant-based high-protein diet that provided 35% of their total calories for six months. The remainder of their calories came from fat (30%) and carbohydrates (35%).

    Participants in both groups saw similar improvements in body composition, including an average weight loss of approximately 8 kilograms (~18 pounds) and reduced visceral (abdominal) fat. Glucose metabolism indicators, such as fasting glucose and glycated hemoglobin levels, improved equally in both groups, as did lipid levels, liver enzymes, and inflammatory markers.

    These findings suggest that high-protein, low-calorie diets—whether animal- or plant-based—can improve body composition, glucose metabolism, and other cardiometabolic markers in people with prediabetes or type 2 diabetes.

    Dietary protein supports muscle hypertrophy and maintenance—critical aspects of glucose metabolism. Learn how to optimize protein intake to support muscle health when following a plant-based diet in this clip featuring Dr. Luc van Loon.

    Read more
  • What are the optimal time-restricted eating patterns for cardiovascular wellness? pubmed.ncbi.nlm.nih.gov
    Diet Obesity Diabetes Cholesterol Time-Restricted Eating Blood Pressure Cardiovascular

    Time-restricted eating is a dietary pattern that restricts the time during which a person eats to a specific window, such as a “16:8" pattern, where they fast for 16 hours a day and consume food only during the remaining eight hours. Evidence suggests that time-restricted eating improves cognitive function, supports weight loss, and reduces systemic inflammation. Findings from a recent review and meta-analysis suggest that time-restricted eating also reduces the risk of cardiovascular disease.

    Researchers analyzed the findings of 33 studies involving 1,725 participants investigating the effects of time-restricted eating on markers of cardiovascular health. They conducted a sub-group analysis to determine how age, health characteristics, and eating patterns influenced the effects of time-restricted eating.

    They found that the effects of time-restricted eating on cardiovascular disease varied according to a person’s risk factors, age, and when they ate. The table below presents their findings for the optimal time-restricted eating for different groups.

    This meta-analysis and review identifies the optimal time-restricted eating interventions for blood pressure, obesity, lipids, and glucose. It effectively provides a best-practices guide for people interested in implementing time-restricted eating as a lifestyle modification to improve cardiovascular health. Learn more about time-restricted eating in this episode featuring Dr. Satchin Panda.

    Read more
  • Vitamin D increases muscle strength and mass without altering body weight in mice. www.biorxiv.org
    Vitamin D Obesity Aging Metabolism Hormones Muscle

    Vitamin D, best known for maintaining calcium balance and bone health, is critical in many physiological processes, including blood pressure regulation, immune function, and cell growth. Evidence now suggests vitamin D also influences body composition and muscle strength. A recent study in mice showed that high vitamin D intake increased muscle strength and mass without altering body weight.

    Researchers fed mice one of three diets, providing low, normal, and high doses of vitamin D for four weeks to achieve deficient, insufficient, and sufficient vitamin D concentrations, respectively. At the end of the fourth week, they assessed the animals' grip strength (a measure of muscle function) and body composition.

    They found that compared to low or normal vitamin D intake, high intake increased grip strength and lean mass and decreased fat mass without altering the animals' weights. High intake also impaired myostatin production and increased the animals' leptin sensitivity and energy expenditure without altering their activity levels.

    Leptin is a satiety hormone that signals the brain to balance energy. When body fat increases or decreases, blood concentrations of leptin change accordingly. Higher leptin levels signal the brain to reduce hunger and boost energy use. However, in obesity, the body becomes less responsive to leptin, dulling its effects on appetite and energy expenditure.

    These findings suggest that vitamin D influences body composition and metabolism by preferentially allocating calories toward muscle development and overall growth rather than fat storage. They also highlight the intricate relationship between obesity and vitamin D status. Learn more about vitamin D in our comprehensive overview article.

    Read more
  • The effects of obesity on the brain mirror those of Alzheimer's disease. www.sciencedaily.com
    Brain Alzheimer's Obesity Aging

    Excess body weight drives gray matter losses similar to those seen in Alzheimer’s disease, a new study shows. The brains of people who were obese showed marked signs of gray matter atrophy in areas of the brain responsible for attention, problem-solving, and reasoning.

    Using neuroimaging data, researchers compared the grey matter patterns of more than 1,300 older adults. Participants included those with Alzheimer’s disease and those who were cognitively healthy, obese but otherwise healthy, or lean.

    The scientists found that obesity and Alzheimer’s disease had similar effects on the brain. Both conditions were associated with gray matter atrophy in the right temporoparietal cortex (an area involved in attention) and the left prefrontal cortex (an area involved in reason, problem-solving, and comprehension). They also found that obesity-related gray matter atrophy patterns didn’t overlap with amyloid-beta or tau protein distribution in the brains of people with Alzheimer’s disease. Amyloid-beta and tau accumulation are widely considered hallmarks of Alzheimer’s disease.

    Excess body weight drives many metabolic disorders, including type 2 diabetes, hypertension, and dyslipidemia. Recent evidence demonstrates that excess body weight impairs cognitive function. The findings from this study suggest that excess body weight drives gray matter losses similar to those seen in Alzheimer’s disease.

    Read more
  • Obstructive sleep apnea may have a suppressive effect on serum testosterone levels in men, independent of BMI and age. (2021) onlinelibrary.wiley.com
    Obesity Sleep Hormones Testosterone

    Sleep apnea increases the risk of low testosterone.

    Men with sleep apnea are more likely to have low testosterone levels, according to a 2021 study. Men with severe apnea are at the greatest risk of low testosterone.

    Researchers reviewed the findings of 18 studies involving more than 1,800 men that examined links between sleep apnea and male testosterone levels. Then they analyzed a subset of the studies after matching the men’s age, body mass index, and severity of their sleep apnea.

    They found that the men with sleep apnea were more likely to have low testosterone levels, even after considering their age and body mass index. However, the subset analysis revealed that this relationship was only notable for those with severe apnea.

    Sleep apnea is a common, but serious, sleep disorder characterized by brief moments of paused or shallow breathing. People with sleep apnea are at greater risk of high blood pressure, stroke, abnormal heart rhythms, heart failure, diabetes, weight gain, and heart attacks.

    This review identifies links between sleep apnea and testosterone levels. It also underscores the importance of diagnosing and treating sleep apnea, particularly among men whose apnea is more severe.

    Read more
  • New insights on how some individuals with obesity can lose weight medicalxpress.com
    Exercise Obesity Mitochondria

    Exercise boosts mitochondrial function and promotes weight loss among people who struggle to lose weight with dieting alone.

    Most weight loss programs focus on reducing caloric intake. Although this strategy works for many people, a subset of people with obesity are diet-resistant – failing to lose weight even when adhering to a low-calorie diet. Findings from a new study suggest that exercise promotes weight loss in diet-resistant women by boosting mitochondrial function.

    Mitochondria are tiny cellular organelles that produce energy in the presence of oxygen. They are often referred to as the “powerhouses of the cell” because of their role in the production of ATP. Mitochondrial dysfunction, the disruption of normal mitochondrial function that occurs over time, is a driver of many chronic diseases, such as cancer, type 2 diabetes, and cardiovascular disease, and is a hallmark of aging.

    The investigators enrolled 20 women with obesity for the study. Half of the women had exhibited diet resistance when following a 900-calorie-per-day diet, while the other half had exhibited diet sensitivity. Both groups participated in a supervised, six-week exercise program that included both aerobic and resistance exercises, performed three times per week. The investigators assessed the women’s body composition and metabolic markers and collected muscle tissue samples for biopsy.

    They found that at the end of the six-week exercise program, the women who were diet resistant exhibited improved body composition and muscle metabolism and increased numbers of muscle mitochondria. The exercise program elicited only minimal effects in women who were diet sensitive. Interestingly, the diet-sensitive women exhibited risk factors associated with metabolic syndrome, suggesting that diet-sensitive obesity confers a greater risk for cardiometabolic disease.

    These findings demonstrate that exercise promotes weight loss and metabolic health in women with obesity and diet resistance and may confer greater health benefits than rapid diet-induced weight loss. Learn more about the benefits of exercise in our overview article.

    Read more
  • Babies Breastfed for a Year or More Better Protected Against Adult Obesity www.newsweek.com
    Obesity Development Breast Milk

    Breastfeeding for a year or longer protects infants against obesity in later life.

    Obesity is a condition in which a person has too much body fat. Having obesity increases a person’s risk for many chronic diseases, including diabetes, heart disease, cancer, and others. New research suggests that breastfeeding for a year or longer protects infants against obesity in later life.

    Breastfeeding is the biologically superior way to feed an infant. The American Academy of Pediatrics recommends exclusive breastfeeding for the first six months of an infant’s life and then continued breastfeeding while introducing age-appropriate foods until an infant is 12 months old or older. This provides the infant optimal nutrition and immunity while supporting growth and development.

    To model short-term versus long-term breastfeeding in humans, the investigators weaned one group of rat pups at three weeks of age (typical weaning time) and another group at four weeks of age (delayed weaning time, comparable to a year or more in humans). Once the animals were weaned, half of each group were fed a normal diet, and half were fed a high-fat diet until they reached adulthood. The investigators measured the animals' bodyweight, analyzed their body composition, and measured their energy expenditure.

    They found that rats that ate a normal diet and were weaned at the typical and delayed times did not differ in terms of bodyweight in adulthood. But rats that had a delayed wean time and were fed a high-fat diet were leaner than those that were weaned at the typical time and fed a high-fat diet. The delayed rats also had higher energy expenditures and more active brown fat, a type of fatty tissue involved in thermogenesis, or heat production. The delayed rats' brown fat contained higher quantities of various proteins involved in thermogenesis, including fibroblast growth factor 21 (FGF21). FGF21 activates neurons in the brain involved in metabolic regulation.

    These findings suggest that prolonged breastfeeding protects against obesity in later life, likely mediated by the influence of FGF21 on metabolic regulation. Learn more about the beneficial effects of breastfeeding for both infants and mothers in our overview article.

    Read more
  • Obese when compared to those with normal body fat had much higher inflammation: 53% higher CRP, 30% higher TNF-a, 17% higher WBC count, 42% higher IL6 linkinghub.elsevier.com
    Obesity Aging Metabolism Inflammation Immune System Metabolic Syndrome IL-6

    Strong link between accumulated visceral fat and chronic inflammation.

    A person’s waist-to-hip ratio compares their waist measurement to that of their hips. A high ratio can be an indicator of excess fat accumulation around the waist, often referred to as visceral fat. Findings from a 2005 study suggest that visceral fat is associated with markers of inflammation.

    Visceral fat is stored in the abdominal cavity near the liver, pancreas, and intestines. The accumulation of visceral fat is linked to increased risk of cardiovascular disease and other chronic diseases. Many factors drive visceral fat accumulation, including poor sleep, an obesogenic diet, and sugar-sweetened beverage intake, among others.

    The study involved more than 3,000 healthy males and females (18 to 89 years old) living in Greece. The investigators calculated the participants' body mass index (BMI) and measured their waist and hip circumferences. Participants provided blood samples for the assessment of inflammatory biomarkers, including C-reactive protein (CRP), tumor necrosis factor-alpha (TNF-alpha), amyloid A (an apolipoprotein secreted in the acute stage of inflammation), white blood cells, and interleukin-6 (IL-6).

    The investigators found that approximately 36 percent of the males and 43 percent of the females had excess visceral fat. Approximately 20 percent of the males and 15 percent of the females had obesity. Participants with greater visceral fat had 53 percent higher CRP, 30 percent higher TNF-alpha), 26 percent amyloid A, 17 percent higher white blood cell counts, and 42 percent higher IL-6, compared to participants with normal fat distribution. The relationship between visceral fat and inflammatory markers was stronger than that between obesity and inflammation, even when considering the participants' age, income, education, and other potential confounding factors.

    These findings suggest that visceral fat and inflammatory processes are linked. The investigators posited that excess accumulation of visceral fat may increase the risk for cardiovascular disease by driving inflammation.

    Read more
  • Lost memory in menopause explained: Estrogen provides a protective role in mitigating effects of visceral fat on brain structural networks and memory jamanetwork.com
    Brain Alzheimer's Obesity Memory Estrogen Visceral Fat

    Estrogen mitigates the association between visceral fat on cognitive decline.

    Estradiol, a form of estrogen, is the primary female sex hormone. It participates in menstrual cycle regulation and drives the development of female secondary sex characteristics, such as breasts, a wider pelvis, and gynoid fat – fat that forms around the hips, thighs, and breasts. Evidence suggests that estradiol exerts both cardioprotective and neuroprotective effects. Findings from a 2020 study demonstrate that estradiol mitigates the association between visceral fat on cognitive decline.

    Cognitive decline is characterized by altered brain structural networks and accelerated degeneration with aging. Scientists don’t fully understand the biological mechanisms that drive cognitive decline, but evidence indicates that visceral fat – a type of fat that accumulates in the abdominal cavity – may play a role. Visceral fat is metabolically active and is associated with increased markers of inflammation and oxidative stress, and decreased levels of anti-inflammatory proteins, such as adiponectin

    The cross-sectional study involved 974 cognitively healthy females and males (average age, ~50 years). Using magnetic resonance imaging, the investigators measured the participants' gray matter volume, cerebral cortex area, intracranial blood vessels, and visceral fat. They also measured estradiol concentrations in a subset (390) of the females. All the participants completed neuropsychological testing to assess memory performance.

    The investigators found that visceral fat exacerbated the harmful effects of aging on the brain’s structural networks in both females and males. However, estradiol mitigated some of these effects in the females, but not the males. Females between the ages of 35 and 55 years (the period surrounding menopause) who had lower estradiol concentrations were more likely to exhibit greater structural network impairments and worse memory performance.

    These findings suggest that estradiol mitigates some of the harmful effects of visceral fat on the brain’s structural networks and cognitive health. Interestingly, the fasting-mimicking diet preferentially depletes visceral fat. Learn more in this clip featuring Dr. Valter Longo.

    Read more
  • Gut microbiota predicts body fat change following a low-energy diet. genomemedicine.biomedcentral.com
    Diet Obesity Microbiome

    Very low-calorie diets elicit extensive changes to the gut microbiota, influencing weight loss.

    Many popular diet programs emphasize calorie reduction as a means to lose weight. However, this approach to weight loss minimizes evidence suggesting that the gut microbiota plays important roles in body weight and likely influences the host’s metabolic response to diet. Findings from a recent study suggest that very low-calorie diets elicit extensive changes to the gut microbiota, influencing how much weight a person loses when dieting.

    Low-calorie diets (1,200 to 1,500 calories per day) and very low-calorie diets (less than 800 calories per day) have gained popularity in recent decades. These diets often rely on the use of meal replacements, typically in the form of ready-made meals, shakes, or bars. When combined with behavior modification, evidence suggests that low-calorie and very low-calorie diets are useful strategies for losing weight.

    The investigators drew on data from the PREVIEW study, a three-year lifestyle intervention study aimed at type-2 diabetes prevention. The current study involved more than 2,200 adults (aged 20 to 70 years) with overweight or obesity and pre-diabetes. Participants consumed a meal replacement that provided approximately 810 calories and 13 grams of fiber daily for eight weeks. They were also allowed to consume up to 400 grams (about 200 calories) of non-starchy vegetables daily. Before and after the intervention, participants provided fecal samples for microbial sequencing.

    The investigators observed that the overall makeup of the participants' gut microbial populations underwent considerable changes over the eight-week intervention. Not only did microbial numbers (termed “richness”) increase, but the diversity of microbes increased, as well. In addition, the numbers of bacteria that may be beneficial for metabolic health, such as Akkermansia and _ Christensenellaceae_, increased, but butyrate production decreased, an indication of fewer butyrate-producing microbes. Butyrate plays important roles in maintaining gut health. These changes were correlated with changes in body fat and weight.

    These findings suggest that very low-calorie diets induce marked changes in the overall composition of microbes in the gut, influencing changes in body fat and weight. Other issues complicate weight loss, however. For example, excess body weight has profound, deleterious effects on the gut microbiome, driving dysbiosis and impairing critical aspects of nutrient metabolism. Of particular concern is the inability to metabolize flavonoids, some of which participate in fat metabolism. This dysbiosis persists, even after weight loss, likely promoting recurrent (or “yo-yo”) obesity. Learn more about this phenomenon in this clip featuring Dr. Eran Elinav.

    Read more
  • Weighted vests may produce changes in body mass through perturbation of a homeostatic "gravitostat," a system regulating appetite by sensing weight www.sciencedaily.com
    Exercise Obesity Metabolic Syndrome

    Exploiting the “gravitostat,” a novel homeostatic mechanism that regulates body weight, promotes weight loss.

    Having overweight or obesity increases a person’s risk of developing many chronic diseases. But losing weight loss is challenging, partly due to homeostatic mechanisms that regulate body weight. Findings from a 2020 study suggest that exploiting a novel homeostatic weight-regulating mechanism called the gravitostat promotes weight loss in humans.

    The concept of the gravitostat first emerged in 2017, when scientists implanted small weights into the abdomens of mice and found that the animals’ food intake decreased, promoting weight loss and improving glucose tolerance. They suggested that the gravitostat regulates weight via a negative feedback system involving bone cells called osteocytes. Because osteocytes can sense changes in bone strain, the investigators proposed that increasing the animals’ body weight activated a biological sensor that communicated with the osteocytes of weight-bearing bones to drive changes in eating behaviors and subsequent weight loss.

    In the 2020 study, the investigators conducted a randomized controlled trial involving 69 adults with mild obesity (body mass index of 30-35). About half of the participants wore a heavy weighted vest (11 percent of their body weight) for eight hours every day for three weeks, while the other half wore a light vest (1 percent of their body weight). Before and after the intervention, the investigators weighed the participants and analyzed their body composition using bioelectrical impedance.

    They found that participants who wore the heavy vest lost an average of 1.37 percent more bodyweight than those who wore the light vest, translating to about 3.5 pounds. Those who wore the heavy vests also lost fat mass and gained fat-free mass. These findings suggest that the gravitostat regulates body weight in humans and exploiting it provides a possible strategy for losing weight.

    Overcoming other aspects of bodyweight homeostasis might still prove challenging, however. Research from Dr. Eran Elinav’s lab suggests that metabolic parameters normalize with weight loss, but characteristics of the microbiome remain unchanged. In other words, the microbiome holds a memory of past obesity that promotes weight regain. Preclinical studies indicate that repeated weight cycling shifts gut microbes to a configuration with an altered ability to metabolize flavonoids — compounds that usually help promote the burning of excess energy by adipose tissue. Learn more in this clip featuring Dr. Eran Elinav.

    Read more
  • Inadequate sleep may preferentially act as a trigger for visceral fat accumulation (randomized controlled crossover study) www.sciencedaily.com
    Diet Obesity Sleep Metabolic Syndrome Visceral Fat

    Inadequate sleep drives abdominal fat gains.

    Visceral fat is body fat that is stored in the abdominal cavity near the liver, pancreas, and intestines. The accumulation of visceral fat is linked to type 2 diabetes, insulin resistance, inflammatory diseases, certain types of cancer, cardiovascular disease, and other obesity-related conditions. Findings from a recent study suggest that not getting enough sleep increases the risk of developing excess visceral fat.

    Sleep is essential for human health. Not getting enough sleep or having poor, fragmented sleep promotes the development of many chronic illnesses, including cardiovascular disease, hypertension, diabetes, stroke, obesity, and depression. Scientists don’t fully understand the mechanisms that drive these effects, but some evidence suggests that disturbances in circadian rhythms play vital roles.

    The trial involved 12 healthy young adults (aged 19 to 39 years) who engaged in an in-patient sleep study. Participants were allowed to have either a full night of sleep (nine hours of sleep opportunity) or restricted sleep (four hours of sleep opportunity) for two weeks. After a three-month washout period, participants repeated the study with the opposite sleep experience. The investigators measured the participants’ caloric intake, energy expenditure, body weight, body composition, and fat distribution throughout the study period.

    They found that when participants were sleep-restricted, they consumed approximately 13 percent more protein and 17 percent more fat (translating to about 300 calories) daily, but their overall energy expenditure did not change. Sleep-restricted participants also gained weight. Much of this weight was in the abdominal area, with a 9 percent increase in total abdominal fat area and an 11 percent increase in visceral fat, compared to when they got a full night’s sleep.

    These findings suggest that insufficient sleep increases caloric intake and promotes weight gain and visceral fat increases. Learn more about the harmful health effects of insufficient sleep in this episode featuring sleep expert Dr. Matt Walker.

    Read more
  • Excess artificial light exposure increases risk of obesity in preschool aged children www.sciencedaily.com
    Obesity Sleep Circadian Rhythm Development Blue Light

    Artificial light exposure increases the risk for obesity among children. Light is the primary signal that entrains the body’s master clock to set its 24-hour circadian cycle. Consequently, the body is synchronized to external light-dark cycles. In recent decades, exposure to light from artificial sources (rather than natural ones) has increased, paralleling the global increases in obesity among adults. Findings from a 2016 study suggest that exposure to artificial light increases the risk for obesity among children.

    Global health experts estimate that more than 42 million children under the age of five years have obesity, roughly one-fourth of whom live in developing nations. Obesity increases a person’s risk for developing chronic diseases such as type 2 diabetes, heart disease, and some cancers. It also imposes considerable financial costs at the individual, healthcare system, and national level.

    The study involved 48 preschool-aged children receiving daycare services in Australia. The investigators measured the children’s baseline body mass index (BMI), sleep duration and timing, light exposure, and physical activity levels via clinical assessment, parent questionnaires, and light and activity trackers. They repeated these measures 12 months later.

    They found that at baseline, children who had longer early exposure to moderate intensity light (such as that from artificial sources) were more likely to have higher BMI, while children who had longer afternoon exposure to bright light (such as that from natural sources) tended to have lower BMI. At the second assessment, the investigators found that even after taking into account sleep duration and timing, BMI, and activity levels, children who had more total light exposure at baseline (due to having earlier exposure) gained more weight than their peers. Specifically, for every hour earlier that the children were exposed to light, they experienced a 0.6 unit increase in BMI. The investigators posited that although this was a small increase, it could be an indicator of a life-long trajectory toward weight gain.

    These findings suggest that greater light exposure, especially when it occurs early in the day from artificial light sources, contributes to weight gain in children. Interestingly, adults that receive early exposure to bright light typically sleep better – a key to maintaining a healthy weight. Learn more in this clip featuring Dr. Matthew Walker.

    Read more
  • Cardio exercise increases the production of FGF21 3x more than strength training: a hormone with relevance to metabolic disorders www.sciencedaily.com
    Exercise Obesity Diabetes Aerobic Strength FGF21

    From the article:

    In a new study published in the scientific Journal of Clinical Investigation – Insight, the researchers show that cardio training on an exercise bike causes three times as large an increase in the production of the hormone FGF21 than strength training with weights. FGF21 has a lot of positive effects on metabolism.

    […]

    Endurance training on a bicycle has such a marked effect on the metabolic hormone that we know ought to take a closer look at whether this regulation of FGF21 is directly related to the health-improving effects of cardio exercise. FGF21’s potential as a drug against diabetes, obesity and similar metabolic disorders is currently being tested, so the fact that we are able to increase the production ourselves through training is interesting', Christoffer Clemmensen elaborates.

    Read more
  • Long-term weight-loss reduces cancer risk in adults with obesity and type 2 diabetes. www.sciencedaily.com
    Cancer Obesity Diabetes

    Obesity and type 2 diabetes cause perturbations in metabolism and immunity that increase the risk of cancer. Bariatric surgery is the most effective intervention for substantial and enduring weight loss in those with obesity and has been shown to [reverse type 2 diabetes](​​https://pubmed.ncbi.nlm.nih.gov/33485454/) and reduce cancer risk. Findings of a recent report demonstrate a lower risk of cancer in patients with obesity and diabetes up to 31 years following bariatric surgery.

    Weight gain occurs when the body stores excess calories in the form of fat in adipose tissue depots around the body. As the amount of energy stored increases, the body’s tolerance for glucose and other fuels decreases, leading to insulin resistance and type 2 diabetes. The high circulating levels of glucose, insulin, insulin-like growth factors, and inflammatory proteins observed in type 2 diabetes increase cancer cell proliferation and suppress apoptosis (programmed cell death). Reducing energy stores through bariatric surgery or other weight-loss therapies restores insulin sensitivity and reduces cancer risk.

    The authors collected data from an ongoing trial with over 4,000 participants investigating the long-term effects of bariatric surgery in adults with obesity and type 2 diabetes. At their baseline visit, participants underwent a physical exam, gave a blood sample, and completed questionnaires regarding health and lifestyle factors. Participants chose to undergo bariatric surgery or receive conventional obesity treatment during the years of 1987 and 2001. They continue to provide additional questionnaire data and blood samples as the study remains ongoing. The investigators followed participants in the current sample for an average of 21 years.

    Participants who chose to undergo bariatric surgery lost an average of 60 pounds two years after the baseline visit, compared to just 7 pounds in participants who received standard obesity treatment. These levels of weight loss remained stable 10 years after the baseline visit. At two years follow-up, 70 percent of participants who underwent surgery had diabetes remission, compared to 34 percent at 10 years follow-up. Bariatric surgery reduced cancer risk by 48 percent in women and 37 percent in the whole group. Participants who underwent surgery and maintained diabetes remission after 10 years had 55 percent reduction in cancer risk compared to participants with diabetes at 10 years follow-up. Participants who did not undergo surgery but achieved diabetes remission had an even greater risk reduction of 60 percent at 10 years follow-up.

    These findings support long-term weight-loss, including bariatric surgery, as a strategy to reduce type 2 diabetes and cancer risk among adults with obesity.

    Read more
  • Insulin improves dopamine signaling in regions of the brain associated with eating behavior. www.sciencedaily.com
    Obesity Insulin Dopamine

    Insulin signaling in the brain influences behavior, weight regulation, motivation, and cognition. Previous research demonstrates that insulin resistance reduces brain volume and cognitive function in middle-aged adults. Results of a new study demonstrate that insulin interacts with dopamine to modulate reward-based behavior and whole-body metabolism.

    Dopamine is a neurotransmitter that regulates activity of the mesocorticolimbic system, a region of the brain involved in reward-based learning. Mesocorticolimbic circuits transmit information from the midbrain to the ventral and dorsal striatum, prefrontal cortex, amygdala, and hippocampus to coordinate emotions, memories, and impulses involved in eating and other rewarding behaviors. Previous research has demonstrated that insulin interacts with dopamine, altering activity of the mesocorticolimbic systems, inducing feelings of satiety and decreasing high-calorie food seeking. However, much of the existing research has been conducted in mice, using very high levels of insulin, making translation to humans difficult.

    The investigators assigned ten male participants (average age, 27 years) with a normal BMI (average BMI, 24) to receive either intranasal insulin or a placebo and undergo a combined PET and MRI scan after having fasted overnight. The researchers gave participants an injection of a radioactive marker called [11C]-raclopride that binds to dopamine receptors so they could measure dopamine-related brain activity during the scan. Participants also completed surveys to assess eating behavior and provided a blood sample for measurement of insulin and other hormones.

    Following administration of intranasal insulin, [11C]-raclopride synaptic binding potential increased in the ventral and dorsal striatum, suggesting an increase in the number of dopamine receptors in these regions. Accordingly, synaptic dopamine concentrations (dopamine that has not bound to a receptor and internalized by the neuron) decreased. Ultimately, this increase in dopamine signaling reduced resting-state activity in the ventral and dorsal striatum and improved functioning of mesocorticolimbic circuits 15 to 45 minutes after insulin exposure. As the participants' response to insulin exposure increased, so did their scores on tests of subjective wellbeing and cognitive control.

    This study, which demonstrated the effects of intranasal insulin on dopamine activity in the mesocorticolimbic system, has important implications for reward-based learning, eating behavior, and obesity. Future research should include participants with insulin resistance to gain a better understanding of the effects of obesity and metabolic disease on the brain.

    Read more
  • Daily avocado consumption improves body fat distribution and reduces visceral fat apple.news
    Nutrition Diet Obesity Metabolic Syndrome Weight Loss Visceral Fat

    Seventy percent of adults living in the United States have overweight (BMI greater than 25) or obesity (BMI greater than 30), putting them at increased risk of metabolic disease. Extra fat stored around the body promotes inflammation and insulin resistance, but extra abdominal fat is particularly dangerous. Findings of a recent report suggest consuming foods rich in unsaturated fat and dietary fiber may improve fat distribution in females.

    Fat stored in the lower body, called subcutaneous fat, is located just under the skin. Fat stored in the abdominal region, called visceral fat, is wrapped around the internal organs (e.g., the liver, pancreas, and intestines). Visceral fat interferes with lipid metabolism in the liver, promoting insulin resistance, type 2 diabetes, and non-alcoholic fatty liver disease. A diet that includes avocados, which are rich in mono-unsaturated fats and dietary fiber, is associated with lower abdominal obesity.

    The investigators recruited 105 adults between the ages of 25 and 45 years who had overweight or obesity. They assigned participants to receive meals with avocado (about one Hass avocado) or meals without avocado that were matched for calories and total fat. The two meals contained different amounts of saturated fat, unsaturated fat, and fiber. Participants consumed their assigned meals once per day for 12 weeks and were told not to change their diet in other ways. Participants completed an oral glucose tolerance test to measure insulin resistance and had their body composition measured using X-ray.

    In females, avocado consumption decreased visceral adiposity and the ratio of visceral to subcutaneous fat, indicating an improvement in body fat distribution. Both males and females in the control group experienced a loss of subcutaneous fat and an increase in the ratio of visceral to subcutaneous fat, indicating a worsening of body composition over the 12 weeks. Avocado consumption had no effect on insulin resistance.

    The authors concluded that avocado consumption improved body fat distribution in females, but had no effects on body fat distribution in males or on insulin resistance in either males or females.

    Read more
  • Redefining the causes of obesity. www.sciencedaily.com
    Diet Obesity Ketogenic Diet

    Obesity is a complex, multifactorial disease influenced by genetic, molecular, environmental, and behavioral factors. Characterized as having excessive body fat, obesity affects more than 650 million people worldwide and markedly increases a person’s risk for many chronic diseases, including cardiovascular disease, type 2 diabetes, cancer, and depression, among others. The authors of a recent report challenge the prevailing theory regarding the root causes of obesity.

    A widely espoused concept in bodyweight management is the “eat less, exercise more” model, based on the principle that the number of calories consumed must be equivalent to (or less than) the number of calories expended. This model is supported by evidence suggesting that consuming high-fat foods drives overconsumption of calories due the foods' high caloric levels, poor ability to provide satisfaction and fullness, and high “pleasure factor.” However, this concept, which forms the basis for national dietary guidelines, public health messaging, and dietary counseling, is inherently flawed, because it fails to take into consideration the biological mechanisms that promote weight gain. Ultimately it places blame on people with obesity and promotes stigmatization.

    In recent decades, scientists have proposed a new model for explaining the root causes of obesity. In this model, body fat accumulation arises from hormonal responses to the consumption of high-glycemic load carbohydrates, ultimately driving a vicious cycle of body fat accumulation, hunger, and food intake. Commonly referred to as the “carbohydrate-insulin” model of obesity, this new paradigm reverses causation and provides a starting point for developing testable hypotheses.

    The concepts presented in this report suggest that what a person eats, rather than how much, plays key roles in body weight management. The authors of the report posited that if the carbohydrate-insulin model is accurate, dietary modifications that limit carbohydrate intake, such as a ketogenic diet, may alter hormonal responses and promote fat oxidation and weight loss. Learn more about the health benefits of the ketogenic diet in this clip featuring Dr. Dominic D'Agostino.

    Link to full publication.

    Read more
  • Maternal body weight influences risk of ADHD and obesity in offspring. apple.news
    Brain Obesity Pregnancy ADHD Genetics

    A woman’s body weight before and during pregnancy can have profound health effects on both mother and child. Women with obesity are at greater risk for developing pregnancy complications that can impair infant neurodevelopment, such as gestational diabetes, preeclampsia, preterm birth, and birth trauma. Findings from a new study suggest that maternal obesity contributes to attention deficit hyperactivity disorder (ADHD) and obesity in offspring.

    ADHD is a neuro-behavioral condition characterized by inattention and/or hyperactive or impulsive behavior that interferes with functioning, learning, or development. Obesity is characterized as having excessive body fat – typically defined as having greater than 25 percent body fat for males and greater than 33 percent body fat for females.

    The study included nearly 3,000 Finnish women and their offspring (~9,400 children). The authors of the study collected information about the children’s behavior and attention span from mothers and teachers. They gathered anthropometric data to determine the mothers' and children’s body mass index (BMI), a proxy for body fatness. They used Mendelian randomization and polygenic risk scores to assess risk for ADHD and/or obesity. Mendelian randomization is a research method that provides evidence of links between modifiable risk factors and disease based on genetic variants within a population. A polygenic risk score estimates a person’s genetic propensity for developing a trait or disease.

    They found that children whose mothers had a high BMI were more likely to develop ADHD, independent of genetic makeup. The Mendelian randomization analysis identified a bidirectional link between developing ADHD and obesity-related traits, suggesting that certain genetic variations may predispose children to both ADHD and obesity concurrently. The polygenic risk score revealed evidence for genetic overlap between having ADHD and greater BMI.

    These finding suggest that both genetic and prenatal environmental factors influence the likelihood that a woman’s child will develop ADHD and obesity. They also underscore the importance of maintaining a healthy maternal body weight before and during pregnancy.

    Read more
  • Drinking oolong tea promotes fat burning. www.eurekalert.org
    Obesity Green Tea Polyphenol

    Tea from the leaves of the Camelia sinensis plant is one of the most widely consumed beverages worldwide. Its consumption is associated with a variety of beneficial health effects. Findings from a recent study suggest that oolong tea consumption promotes weight loss.

    Many types of tea from Camelia sinensis exist, but they are generally classified as green, oolong, or black. The differences in the three types arise during processing, where they undergo various degrees of oxidation. Green tea is unoxidized; oolong tea is partially oxidized; and black tea is fully oxidized. Tea contains several bioactive compounds, including catechins and caffeine. Catechins are polyphenolic compounds that exert antioxidant properties. Caffeine is a potent stimulant.

    The intervention study involved 12 healthy non-obese men between the ages of 20 and 56 years. The participants consumed one of three beverages at breakfast and lunch for three 14-day sessions: oolong tea containing 51.8 milligrams of caffeine and 48.5 milligrams of catechins; a beverage containing 51.8 milligrams of caffeine; or a placebo beverage. A washout period of about two weeks separated each session. The men drank no other beverages containing caffeine or alcohol during the study period. They underwent 24-hour indirect calorimetry to monitor their metabolism and polysomnographic sleep recording to gauge their sleep quality.

    The authors of the study found that fat oxidation increased by roughly 20 percent when the participants drank the oolong tea or pure caffeine beverage, but not when they drank the placebo beverage. The effects of consuming oolong tea continued to a greater degree while the participants were asleep. Neither of the caffeine-containing beverages promoted an increase in the men’s energy expenditure, and none of the men exhibited alterations in sleep quality, suggesting that they developed a tolerance to the stimulatory effects of caffeine.

    These findings suggest that oolong tea stimulates fat oxidation, especially during the overnight fast.

    Read more
  • Brown fat is linked with lower risk of some chronic diseases. www.sciencedaily.com
    Obesity Cold Stress Brown Fat

    Obesity, or having excess body fat, is a known risk factor for a wide range of diseases, including diabetes, cancer, and dementia. Findings from a new study indicate that having brown fat is linked with lower risk of some chronic diseases.

    Brown fat, also known as brown adipose tissue, is found in all mammals and is particularly abundant in newborns. Unlike white fat, brown fat is a metabolically active tissue that is rich in mitochondria. It helps maintain body temperature during cold exposure, during which its uptake of glucose is eightfold higher than that of muscle tissues.

    The authors of the retrospective case-control investigation reviewed imaging reports from more than 52,000 adults who had undergone diagnostic positron emission tomography (PET) scans (nearly 135,000 total scans). They also reviewed the participants' health records.

    The PET scans revealed that nearly 10 percent of the study participants had detectable brown fat. Those who had brown fat were less likely to have type 2 diabetes, abnormal lipid levels, coronary artery disease, cerebrovascular disease, congestive heart failure, and hypertension. They were also more likely to have favorable blood glucose, triglyceride, and high-density lipoprotein levels. These effects were greatest in people who had obesity or overweight. The authors suggested that having brown fat might counteract some of the harmful effects of obesity.

    These findings indicate that brown fat may protect against some diseases and suggest that adopting lifestyle behaviors that promote production of brown fat, such as exercise or cold exposure, may be beneficial. Some nutrients and bioactive compounds, such as curcumin, capsaicin, resveratrol, and omega-3 fatty acids, may increase brown fat production, too.

    Read more
  • From the blood to the brain: BDNF-producing blood cells travels to the hypothalamus in adults, regulating and suppressing appetite [animal research] www.sciencedaily.com
    Brain Obesity BDNF

    From the article:

    We knew that blood cells produced BDNF,“[…] "We didn’t know why it was produced in blood cells.”

    Dr. Hiroshi Urabe and Dr. Hideto Kojima, current and former postdoctoral fellows in Chan’s laboratory respectively, looked for BDNF in the brains of mice who had not been fed for about 24 hours. The bone marrow-derived cells had been marked with a fluorescent protein that showed up on microscopy. To their surprise, they found cells producing BDNF in a part of the brain’s hypothalamus called the paraventricular nucleus.

    “We knew that in embryonic development, some blood cells do go to the brain and become microglial cells,” said Chan. […]“This is the first time we have shown that this happens in adulthood. Blood cells can go to one part of the brain and become physically changed to become microglial-like cells.”

    A new way to affect appetite and obesity?

    When normal bone marrow cells that produce BDNF are injected into the third ventricle (a fluid-filled cavity in the brain) of mice that lack BDNF, they no longer have the urge to overeat, said Chan.

    All in all, the studies represent a new mechanism by which these bone-marrow derived cells control feeding through BDNF and could provide a new avenue to attack obesity, said Chan.

    He and his colleagues hypothesize that the bone marrow cells that produce BDNF fine tune the appetite response, although a host of different appetite-controlling hormones produced by the regular nerve cells in the hypothalamus do the lion’s share of the work.

    Read more
  • Environmental enrichment alone produces browning of fat and enhanced weight control not accountable by exercise alone [animal study]
    Brain Obesity Memory Fat BDNF Thermogenesis

    From the article:

    “Up to now the only known approach to inducing brown fat has been through exposure to chronic cold. Our research reveals a novel way of doing this without cold exposure. We show that animals living in an enriched environment become lean and resistant to diet-induced obesity, even in the presence of unlimited food.”

    […]

    The current study used a similarly designed environment, with 15-20 mice housed in large containers equipped with running wheels, tunnels, huts, wood toys, a maze, and nesting material, in addition to unlimited food and water.

    Key findings include the following:

    • Enriched animals showed a significant reduction in abdominal white fat mass (49 percent less than controls).

    • Exercise (running in a wheel) alone did not account for the changes in body composition and metabolism of enriched animals.

    • Fed a high fat diet (45 percent fat), enriched animals gained 29 percent less weight than control mice and remained lean, with no change in food intake. Enriched animals also had a higher body temperature, suggesting that greater energy output, not suppressed appetite, led to the resistance to obesity.

    Read more
  • Increases in brain-derived neurotrophic factor from aerobic exercise associated with appetite suppression, weight loss, and improved blood pressure www.sciencedaily.com
    Exercise Brain Obesity Blood Pressure Aerobic Weight Loss BDNF

    From the article:

    The team evaluated blood levels of BDNF before and after a three-month program of aerobic exercise in 15 overweight or obese men and women. The seven men and eight women, ages 26 to 51, worked out on a treadmill and bicycle. They were asked about their calorie intake and told to continue eating their usual number of calories. The participants were unaware that one of the study’s objectives was to evaluate changes in food intake.

    At the end of the study, the subjects had decreased BMI, waist circumference, and blood pressure, the data showed. They also reported consuming fewer calories than at the beginning of the study. Over the three months, BDNF levels greatly increased. This higher the concentration of BDNF, the less the subject’s intake of calories and the greater the weight loss, Araya said.

    Thus, it is possible that increases in BDNF suppress appetite, she said. They did not test appetite suppression directly, but some past studies have shown that aerobic exercise suppresses appetite.

    Read more
  • Omega-3 fatty acids decrease oxidative stress and affect biomarkers of aging. www.sciencedaily.com
    Obesity Aging Omega-3 Inflammation

    As the human body ages several changes occur, including the gradual erosion of the protective caps on the ends of chromosomes, known as telomeres. A 2012 study suggests that supplementing with omega-3 fatty acids can counteract telomere shortening and slow aging.

    Telomeres function as a protective buffer against DNA loss during replication and DNA damage caused by inflammation, reactive oxygen species, and other chemical compounds. Telomeres get shorter with age and telomere length is a biological marker for age.

    Previous research has demonstrated that many factors can affect the rate of telomere shortening. The dietary balance of the essential polyunsaturated fatty acids (PUFAs) omega-3 and omega-6 — which influence inflammation — might be a factor. The current study investigated whether blood levels of these polyunsaturated fatty acids affect telomere stability.

    The double-blind randomized controlled trial involved 106 adults between the ages of 40 and 85 years who were sedentary and overweight. The authors of the study provided participants with a supplement containing 1.25 grams or 2.5 grams of omega-3 fatty acids or a placebo. To evaluate the influence of the omega-3 fatty acids versus placebo, the authors measured telomere length, telomerase activity, and markers of oxidative stress (known as F2-isoprostanes). They found that supplementation at both doses lowered the omega-6 to omega-3 fatty acid ratio in the blood, which was associated with longer telomere length. They also observed that omega-3 fatty acid supplementation decreased markers of oxidative stress by 15 percent.

    These findings suggest that consumption of omega-3 fatty acids in quantities high enough to lower the omega-6 to omega-3 ratio in the blood can slow aging.

    Read more