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Time-Restricted Eating

Time-restricted eating featured article

Time-restricted eating is a form of daily fasting wherein the time of the day during which a person eats is limited, or compressed. People who practice time-restricted eating typically eat during an 8- to 12-hour daytime window and fast during the remaining 12 to 16 hours. Unlike intermittent fasting, which involves caloric restriction, time-restricted eating permits a person to eat as much as they want during the eating window. Time-restricted eating aligns the eating and fasting cycles to the body’s innate 24-hour circadian system. Within the scientific literature, time-restricted eating primarily refers to human trials, while time-restricted feeding primarily refers to animal studies; however, both terms are occasionally used interchangeably.

The circadian system is composed of multiple cellular clocks found in all cells throughout the body. These clocks orchestrate the regulation of gene expression that coordinates metabolic programs needed to support bodily functions....

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Dr. Rhonda Patrick discusses microdosing nicotine, GlyNac benefits, intermittent fasting and hair loss, and cold & flu relief.

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This Is Everything Rhonda Patrick Eats in a Day

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In this clip, Dr. Rhonda Patrick shares her approach to time-restricted eating, meal composition, protein sources, and her typical daily eating schedule.

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How to Improve Metabolic Health with HIIT, Circadian-Timed Eating, & Sleep

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Dr. Rhonda Patrick explains how HIIT, circadian-timed eating, and quality sleep improve metabolic health and reduce chronic disease risk.

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    Time-restricted eating entrains peripheral circadian oscillators, thereby reinforcing central sleep-wake timing and improving sleep regularity.

News & Publications

  • Time-restricted eating helps lose weight without compromising sleep, mood, or quality of life, regardless of when the eating window occurs. jamanetwork.com
    Time-Restricted Eating Weight Loss

    Meal timing may influence more than just hunger—it can affect our sleep, mood, and day-to-day functioning. Time-restricted eating, a strategy that limits food intake to a specific window each day, has shown promise for weight loss and improved metabolic health, and may also support other aspects of well-being. A recent study found that people who followed time-restricted eating lost about 3 kilograms (roughly 6.5 pounds) more than those who didn't, regardless of whether they ate early, late, or chose their own schedule.

    Researchers provided 197 adults who had overweight or obesity with guidance on following a Mediterranean-style diet. Then, they assigned some of the participants to one of three schedules: an early time-restricted eating schedule (starting before 10 a.m.), a late schedule (starting after 1 p.m.), or a self-selected 8-hour eating window. The remainder followed a typical daily eating pattern. The researchers measured the participants' sleep with wearable devices and assessed mood and quality of life through standard questionnaires before and after the intervention.

    They found no meaningful differences between the groups in total sleep time, stress, depression, anxiety, or general quality of life. For example, sleep duration differed by only about 12 minutes across groups, and mood scores remained stable. There were also no marked differences between early, late, and self-selected eating windows.

    These findings suggest that incorporating time-restricted eating into a weight loss program is unlikely to harm sleep, mood, or quality of life, regardless of the time of day the eating window falls. Evidence suggests time-restricted eating offers a wide range of health benefits. Learn more in this clip featuring Dr. Satchin Panda.

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  • Fasting-based dietary strategies, including intermittent fasting and time-restricted eating, show slight superiority over calorie restriction for promoting weight loss and improving insulin sensitivity. www.mdpi.com
    Diet Obesity Metabolism Fasting Time-Restricted Eating Weight Loss

    With millions worldwide affected by obesity-linked conditions like diabetes and cardiovascular disease, understanding which dietary methods are most effective has become crucial. A recent review and meta-analysis found that fasting-based strategies are slightly more effective for promoting weight loss and improving insulin sensitivity than calorie restriction.

    Researchers reviewed 10 randomized controlled trials involving more than 600 participants to compare the effects of fasting-based and calorie-restricted diets on weight loss and metabolic health. Fasting-based strategies included intermittent fasting, time-restricted eating, and alternate-day fasting, while continuous calorie restriction involved reducing daily caloric intake by 20% to 40% without meal timing changes.

    They found that both methods effectively reduced body weight, with participants losing around 5.5 to 6.5 kilograms (roughly 12 to 14 pounds) after six months. Fasting-based approaches had a slight edge in short-term weight and fat loss—about 1 kilogram (2.2 pounds) more than calorie restriction—but both approaches had similar effects on lean body mass, waist and hip circumference, blood pressure, lipid levels, and glucose metabolism. Notably, fasting-based methods also lowered fasting insulin levels and improved insulin sensitivity.

    These findings suggest that while both methods support weight loss, fasting-based diets may offer additional short-term metabolic benefits. Learn more about fasting-based diets and calorie restriction from these great resources:

    What type of fasting is best? Caloric restriction vs. periodic fasting and the importance of re-feeding after a fast The link between sirtuins, calorie restriction, fasting, and the insulin pathway Topic article: Fasting

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  • Late-night eating increases the risk of death from diabetes by as much as 131 percent. www.nature.com
    Diet Diabetes Circadian Rhythm Mortality Time-Restricted Eating

    The body’s circadian rhythms – its 24-hour biological, hormonal, and behavioral cycles – are optimized for daytime eating. Consequently, eating in the late evening or nighttime hours may increase a person’s risk of developing chronic diseases, such as type 2 diabetes. A recent study found that nighttime eating increased the risk of premature death from diabetes by as much as 131 percent.

    The investigation included more than 41,000 adults enrolled in NHANES, an ongoing study that assesses the health and nutritional status of people in the U.S. Researchers gathered information about the participants' eating habits (including timing and food quality) and tracked their health and death rates for about nine years.

    They found that compared to eating before 10 p.m., - Eating between 11 p.m. and midnight increased the risk of premature death from diabetes by 131 percent. - Eating between midnight and 1 a.m. increased the risk of premature death from any cause by 38 percent. - Eating between 1 a.m. and 2 a.m. increased the risk of premature death from cancer by 109 percent.

    When they considered the frequency of eating late, they found that eating at night at least once increased the risk of premature death from all causes, including diabetes. Food quality influenced death risk, too, with high-calorie foods increasing the risk of premature death from all causes by 21 percent and from diabetes by 97 percent. Participants who ate late tended to have higher HbA1c, fasting glucose, and oral glucose tolerance test results, indicative of poor glucose metabolism.

    These findings suggest that late-night eating, particularly high-calorie foods, increases the risk of early death from all causes, especially diabetes. Shift work, jet lag, parenting, and modern lifestyles contribute to late-night eating, increasing disease and early death risk. Learn more in this clip featuring Dr. Satchin Panda.

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  • 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.

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  • Time-restricted eating decreases inflammation and leptin — a hormone that regulates food intake. www.sciencedirect.com
    Diet Hormones Inflammation Time-Restricted Eating

    In the setting of obesity, adipocytes (fat cells) enlarge to accommodate immense quantities of fat. These specialized cells eventually become dysfunctional, releasing inflammatory proteins and activating immune cells called macrophages. In turn, macrophage activation promotes a vicious cycle of inflammation and further dysfunction, increasing the risk of many chronic diseases, including cardiovascular disease and cancer. A recent review and meta-analysis found that time-restricted eating reduces inflammatory markers and leptin.

    Researchers reviewed the findings of randomized-controlled trials investigating the effects of time-restricted eating on inflammation. Their analysis included 25 trials involving 936 participants.

    They found that time-restricted eating reduced participants' pro-inflammatory markers (C-reactive protein, TNF-alpha, and interleukin-6) and increased levels of adiponectin, a protein produced by adipose tissue that regulates glucose levels and fatty acid breakdown in the body. Time-restricted eating also reduced the participants' leptin, a hormone that drives food intake.

    These findings suggest that time-restricted eating is a viable strategy for reducing inflammation. Previous research has shown that time-restricted eating promotes weight loss in people with obesity.

    Time-restricted eating is a dietary pattern that limits food intake to certain hours of the day without overtly reducing caloric intake. It exploits the body’s innate 24-hour patterns and provides the body an essential downtime where it can focus on DNA and cellular repair and restoration rather than digestion. The most common version of time-restricted eating is a “16:8” pattern, where all the day’s calories are consumed within an eight-hour window, leaving 16 hours for fasting, including the hours during which a person is asleep. Learn about the many health benefits associated with time-restricted eating in this clip featuring Dr. Satchin Panda.

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  • Time-restricted feeding corrects Alzheimer’s circadian disruptions in mice, reducing amyloid protein accumulation and improving memory. www.sciencedaily.com
    Brain Alzheimer's Dementia Time-Restricted Eating

    Alzheimer’s disease is the most common form of dementia, affecting more than 55 million people worldwide. People with Alzheimer’s disease often experience altered circadian rhythms, manifesting as altered sleep/wake cycles and difficulty in falling and staying asleep. A new study in mice suggests that time-restricted eating restores normal circadian rhythmicity and reduces amyloid-beta plaque formation in the brain.

    Using a mouse model of Alzheimer’s disease, researchers gave one group of mice free access to food throughout the day but fed another group on a time-restricted schedule (limited to a six-hour window each day), translating to about 14 hours of fasting for humans. Then, they evaluated the animals' gene expression, amyloid-beta accumulation, and cognitive performance.

    They found that the mice fed on the time-restricted schedule had better memory function, were less hyperactive at night, followed a more regular sleep schedule, and experienced fewer disruptions during sleep than the mice allowed free access to food. The restricted mice also performed better on cognitive assessments and exhibited less amyloid-beta accumulation in the brain. Time-restricted feeding also normalized gene expression in the hippocampus, an area of the brain involved in memory and often affected by Alzheimer’s disease.

    These findings suggest that time-restricted eating mitigates the behavioral symptoms and pathological features associated with Alzheimer’s disease. Robust evidence indicates that time-restricted eating influences multiple aspects of human health. Learn more about time-restricted eating in this clip featuring Dr. Satchin Panda.

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  • Findings suggest restricting eating to an eight-hour window enables similar weight loss as cutting calories by 25 percent. www.latimes.com
    Diet Metabolism Time-Restricted Eating Weight Loss

    Traditional weight-loss programs typically emphasize calorie restriction – often cited as the primary reason participants drop out. But time-restricted eating is a weight loss strategy that limits one’s daily eating window to a specific period without focusing on restricting calories. A new study found that time-restricted eating was as effective as calorie restriction for weight loss.

    The study included 90 adults with obesity who followed one of three dietary patterns for a year: time restriction, calorie restriction, and no restriction (a control group). The time-restricted group ate during an eight-hour window, from noon to 8:00 p.m., without limiting calories. The calorie-restricted group cut their calories by 25 percent. The control group ate during a 10-hour (or more) window and did not change their diets. Researchers assessed the participants' body weights, metabolic markers, and caloric intake throughout the study.

    They found that the time-restricted and calorie-restricted groups experienced considerable weight loss compared to the control group by the end of the year. The time-restricted group lost more than 10 pounds (~4.8 percent of their body weight), while the calorie-restricted group lost nearly 12 pounds (~5.3 percent). There was no statistically significant difference in weight loss between the two groups. Notably, the control group averaged a 2.4-pound weight gain over the year.

    These findings suggest that time-restricted eating is as effective for weight loss as calorie restriction. In this study, the eating window began around noon – often described as a “late” window. However, some evidence indicates that an early eating window is more beneficial than a later one. Learn more about time-restricted eating in this episode featuring Dr. Satchin Panda.

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  • Time-restricted eating activates genes involved in metabolism and autophagy. www.sciencedaily.com
    Metabolism Genetics Autophagy Time-Restricted Eating

    Time-restricted eating influences the activation of roughly 70 percent of all genes in mice, a new study shows. Mice that ate on a time-restricted schedule had fewer active genes involved in inflammation and oxidative stress and more active genes involved in metabolism and autophagy – a cellular defense mechanism.

    Researchers fed two groups of mice a Western-style diet, which is high in fat and sugars, for seven weeks. One group was allowed to eat whenever they chose to, but the other group was allowed to eat only during a nine-hour window each day. At the end of the seven-week intervention, the researchers analyzed gene activity in the animals' tissues at different times of the day.

    They found that time-restricted eating altered the activity of more than 80 percent of genes involved in protein synthesis, folding, and maintenance. They also found that time-restricted eating altered amino acid, fat, and glucose metabolism and re-aligned the circadian rhythms of the animals' organs.

    These findings suggest that time-restricted eating influences gene activity in mice. If the findings translate to humans, they could have far-reaching implications for chronic metabolic disorders, neurodegenerative diseases, cancer, and other diseases. Learn more about the health benefits of time-restricted eating in this episode featuring Dr. Satchin Panda, the senior investigator for this study.

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  • Eating late at night promotes weight gain. www.sciencedaily.com
    Diet Circadian Rhythm Time-Restricted Eating Weight Loss

    Maintaining a healthy body weight presents challenges for many people. Previous research has shown that the timing of food intake plays important roles in managing body weight. Findings from a recent study suggest that late-night eating is counter to the body’s circadian rhythms, increasing the risk of weight gain.

    Circadian rhythms modulate a wide array of the body’s physiological processes, including the production of hormones that regulate sleep, hunger, metabolism, and others, ultimately influencing body weight, performance, and susceptibility to disease. Coordination of meal timing with the circadian rhythm can affect aspects of metabolic health, including glucose regulation and insulin sensitivity.

    The study involved 16 adults (average age, 37 years) who had overweight or obesity. The participants followed an “early” eating schedule and then a “late” eating schedule for six days each, separated by a wash-out period of three to 12 weeks. The researchers controlled the participants' caloric intake, physical activity, sleep, and light exposure throughout the two interventions. They also collected adipose tissue samples from the participants for analysis of gene expression. Participants reported their hunger and appetite.

    The researchers found that when the participants ate later in the day, their hunger and appetite-regulating hormones increased, but their energy expenditure decreased. In addition, eating late altered biochemical pathways involved in fat metabolism and storage.

    These findings suggest that eating late influences appetite, energy expenditure, and molecular pathways in fat tissue, underscoring the role of circadian rhythmicity in bodyweight management. Watch this episode in which Dr. Satchin Panda summarizes tips and strategies that anyone can follow to ensure a healthy circadian pattern.

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  • Eating during the day, rather than at night, improves mood. www.sciencedaily.com
    Depression Circadian Rhythm Time-Restricted Eating

    People who regularly keep late hours – for leisure, shift work, or other reasons, such as caring for a newborn – often have misaligned circadian rhythms, placing them at greater risk for depression and anxiety. Research has shown that daytime eating helps realign those rhythms. Findings from a recent study suggest that eating during the day, rather than at night, reduces the risk of depression and anxiety-related disorders.

    The investigators subjected 19 healthy adults (average age, 26 years) to a unique protocol that altered the participants' light exposure, desynchronizing their normal circadian rhythms and mimicking the effects of shift work. During the desynchronized period, half of the participants ate their meals in both the daytime and nighttime, while the other half ate all their meals in the daytime. The investigators monitored the participants' food intake, sleep duration, and depression- and anxiety-like mood levels.

    They found that among participants who ate during both the day and night, depression-like mood levels increased by 26 percent, and anxiety-like mood levels increased by 16 percent. However, participants who ate all their meals during the day did not experience mood changes. Even though the groups' caloric intake, macronutrient intake, physical activity, sleep duration, and eating window duration (12 hours) were identical, eating during the night worsened their moods. As the participants' eating became more misaligned, their symptoms became more severe.

    These findings suggest that restricting mealtimes to daytime hours can offset the mood-altering effects of misaligned circadian rhythms. Learn more about the effects of time-restricted eating on circadian rhythms in this clip featuring Dr. Satchin Panda.

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  • Time-restricted feeding restores healthy circadian oscillations in the ileal microbiota. medicalxpress.com
    Microbiome Circadian Rhythm Time-Restricted Eating

    Compositional oscillations of the gut microbiome are essential for normal peripheral circadian rhythms, both of which are disrupted in diet-induced obesity (DIO). Although time-restricted feeding (TRF) maintains circadian synchrony and protects against DIO, its impact on the dynamics of the cecal gut microbiome is modest. Thus, other regions of the gut, particularly the ileum, the nexus for incretin and bile acid signaling, may play an important role in entraining peripheral circadian rhythms. We demonstrate the effect of diet and feeding rhythms on the ileal microbiome composition and transcriptome in mice. The dynamic rhythms of ileal microbiome composition and transcriptome are dampened in DIO. TRF partially restores diurnal rhythms of the ileal microbiome and transcriptome, increases GLP-1 release, and alters the ileal bile acid pool and farnesoid X receptor (FXR) signaling, which could explain how TRF exerts its metabolic benefits. Finally, we provide a web resource for exploration of ileal microbiome and transcriptome circadian data.

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  • Time-restricted eating improves athletic performance. www.mdpi.com
    Exercise Fasting Fat Muscle Time-Restricted Eating

    Time-restricted eating involves restricting the timing of food intake to certain hours of the day (typically within an 8- to 12-hour time window) without an overt attempt to reduce caloric intake. Increasing the amount of time spent fasting each day has been used to treat metabolic diseases such as type 2 diabetes and high cholesterol, increase muscle mass, decrease fat mass, and improve exercise performance. Findings of a recent report demonstrate the beneficial effects of time-restricted eating on exercise performance in power athletes.

    Increasing muscle mass and decreasing fat mass is an important goal for many athletes because increasing their strength-to-mass ratio improves performance. While time-restricted eating is one strategy to improve body composition, previous research has shown that other types of intermittent fasting (e.g., religious fasting during Ramadan) decrease power output and endurance. Another study involving intermittent fasting with caloric restriction found similar deficits in athletic performance. The effects of long-term time-restricted eating without caloric restriction are unknown.

    The researchers recruited healthy young males who were currently practicing a power-sport at least three times per week and had been practicing for at least three years. Twelve participants (average age, 22 years) completed four weeks of time-restricted eating and four weeks of a standard meal pattern in random order with two weeks of wash-out in between. During the time-restricted eating period, participants consumed all of their food within an eight-hour window. The researchers measured body composition using X-ray and athletic performance using the Wingate test, a cycling challenge that measures power and total work.

    Time-restricted eating produced a significant increase in total work (a measure of force over a set distance) and average power output (a measure of work over time). These improvements translated to a one second reduction in sprinting time. The participants achieved this change after four weeks of time-restricted eating, but not after one week. Time-restricted eating did not improve peak power, endurance, or body composition.

    Time-restricted eating, along with regular training, improved exercise performance in athletes. Given that the difference between the current and former 400 meter running world records is only 15 hundredths of one second, the one second decrease in sprinting time produced by time-restricted eating is meaningful.

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  • Time-restricted feeding reduces weight gain and cholesterol in male mice. www.sciencedaily.com
    Cholesterol Fasting Fat Muscle Sugar Time-Restricted Eating Weight Loss Lipopolysaccharide

    A Western diet pattern, characterized by a low intake of fruits and vegetables and a high intake of sugar and processed foods, promotes the development of obesity and metabolic disease. Time restricted eating has been shown to decrease weight and improve metabolic health in humans. However, factors such as age and sex modulate both susceptibilty to obesity and likelihood of responding to weight-loss treatments. Authors of a new report found that male mice experienced greater metabolic benefit from time-restricted feeding than females.

    Time-restricted eating, the practice of limiting food intake to an 8- or 12-hour window, is an emerging therapy for the treatment and prevention of metabolic diseases. Much of the research about time-restricted eating in humans is based on research of time-restricted feeding in mice, which has elucidated many of the cellular mechanisms related to [time-restricted eating’s benefits.](​​https://journals.physiology.org/doi/full/10.1152/ajpregu.00775.2005) These two terms distinguish which population, humans or non-human animals, is practicing time-restricted food intake.

    The prevalence of obesity is on the rise in the industrialized world, a problem compounded by an increasing average age in the same populations. The accumulation of extra fat throughout life puts a person at greater risk of metabolic disease as they age. Females are more likely to gain and retain fat mass than males; however, pre-menopausal females tend to have lower rates of type 2 diabetes and cardiovascular disease due to the protective effects of estrogen. Previous research in humans has demonstrated weight loss and improved metabolic health with time-restricted eating; however, additional research is needed to understand the sex- and age-dependent effects of time-restricted eating.

    The researchers used male and female mice of two ages: three months old (equivalent to 20-year-old humans) and 12 months old (equivalent to 42 year-old-humans). They fed mice a chow diet representative of a Western diet pattern with 17 percent of calories from sugar (human equivalent of about 25 ounces of soda per day) and 45 percent of calories from fat including lard and soybean oil. Current dietary guidelines recommend limiting solid fats such as lard). Half of the mice had 24-hour access to food while the other half only had restricted access, limited to just nine hours per day. Mice continued their diet for a total of 12 to 13 weeks. After 10 weeks, the researchers measured changes in the animals' body weight, glucose sensitivity, serum cholesterol, fatty liver, muscle performance, and immune response when challenged with bacterial endotoxin.

    Although mice in the time-restricted feeding group consumed the same amount of food as mice with constant access to food, time-restricted feeding resulted in 15 percent less weight gain in young male mice and 23 percent less weight gain in older male mice. Time-restricted feeding did not significantly prevent weight gain in female mice. Male mice also experienced a greater reduction in serum cholesterol with time-restricted feeding compared to females. Both older male and female mice had lower rates of insulin resistance and fatty liver while on time-restricted feeding. This protection was likely due to changes in gene expression that increased glucose uptake by and decreased glucose output from the liver. In young male mice, time-restricted feeding preserved muscle mass, function, and performance, but not in young females. Finally, when challenged with bacterial endotoxin, older mice practicing time-restricted feeding were significantly more likely to survive septic shock than mice with 24-hour access to food, demonstrating better health and resilience.

    Time-restricted feeding improved survival of septic shock and provided protection against insulin resistance and fatty liver in both sexes; however, male mice experienced greater reductions in body weight and serum cholesterol and maintained greater muscle mass and performance compared to female mice. The authors noted that their research is of particular interest considering the increased risk of severe COVID-19 illness in those with poor metabolic health.

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  • Time-restricted eating improves insulin sensitivity in healthy men. academic.oup.com
    Time-Restricted Eating

    Insulin sensitivity refers to how well the body’s cells respond to insulin – a critical aspect of maintaining healthy blood glucose levels. Lifestyle behaviors and dietary modification may help improve insulin sensitivity. Findings from a new study suggest that early time restricted eating improves insulin sensitivity.

    Time-restricted eating is a form of daily fasting that aligns the eating and fasting cycles to the body’s innate 24-hour circadian system. People who practice time-restricted eating typically eat during an 8- to 12-hour daytime window and fast during the remaining 12 to 16 hours. Unlike intermittent fasting, which involves caloric restriction, time-restricted eating permits a person to eat as much as they want during the eating window.

    The intervention study involved 16 healthy young men (average age, 23 years) who were moderately active and had BMIs between 18 and 27. After an overnight fast, the men underwent indirect calorimetry testing to determine their resting metabolic rate – the rate at which the body burns calories when at rest. The men wore continuous glucose monitors and tracked their dietary intake and physical activity.

    After a one-week baseline period, the men’s metabolic response to a liquid test meal containing carbohydrates and protein was assessed. Eight of the men began the time-restricted dietary pattern, in which they consumed all their calories (eating whatever they wanted) during a window between 8 a.m. and 4 p.m. – considered “early” time-restriction. Nine months later, another group of eight men took part in the same process, but they ate whenever they wanted to, but their caloric intake was matched to that of what the men ate during the time-restricted eating period (which was about 400 calories per day lower than usual due to the limited time frame in which they ate). Both interventions lasted two weeks, after which both groups of men underwent metabolic testing again.

    The men who followed the time-restricted eating pattern reduced their overall caloric intake and lost more weight, compared to the men who followed a calorie-restricted diet. Similarly, the men following the time-restricted diet experienced improvements in their whole-body insulin sensitivity as well as skeletal muscle uptake of glucose and branched-chain amino acids. The two groups of men had similar physical activity levels.

    These findings demonstrate that early time-restricted eating improves insulin sensitivity and promotes weight loss in health men and has potential applications for interventions in people who are metabolically compromised. You can read about time-restricted eating in our overview article.

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  • Brain aging emerges in the late 40's but dietary ketosis increases overall brain activity and stabilizes functional networks. news.stonybrook.edu
    Brain Aging Ketosis Insulin Time-Restricted Eating Carbohydrates Ketogenic Diet

    Insulin resistance and poor blood glucose control – defining characteristics of type 2 diabetes – drive changes associated with brain aging and cognitive decline. A growing body of evidence suggests that dementia is the manifestation of insulin resistance and altered metabolism in the brain. A recent study suggests that dietary patterns that promote ketosis improve brain metabolism and function.

    Ketosis is a metabolic state that results in the body’s production and use of ketones (byproducts of fatty acid metabolism). It occurs under conditions of fasting, starvation, and low carbohydrate intake. Ketones induce physiological and metabolic responses to promote brain health.

    The study had multiple components. First, the authors of the study investigated the time course of human brain aging. Using functional MRI (fMRI) data from more than 900 people between the ages of 18 and 88 years, they determined that neural network stability is a biomarker of brain aging, and the loss of network stability manifests as early as the fifth decade of life (average age, 47 years). They found that the greatest changes in the brain occur around the age of 60 years.

    Then they performed fMRI scans on 12 young adults (average age, 28 years) to assess how different energy sources – glucose versus ketones – alter brain function. Each participant underwent three scans under different dietary conditions: a normal diet without fasting, a normal diet with overnight fasting, or a ketogenic diet for one week. They performed fMRI scans on 30 young adults (average age 29 years) 30 minutes after they took an oral bolus of either glucose or ketones or after following their normal diet with overnight fasting. The authors of the study measured the participants' blood glucose and ketone levels before and after each of the scans.

    The fMRI scans revealed that ketones increased overall brain activity and stabilized functional networks, but glucose had the opposite effect, regardless of whether the ketones were produced endogenously or supplied from exogenous sources. These findings suggest that dietary interventions that increase ketone production may be useful in mitigating the harmful effects of glucose on the brain.

    Certain dietary patterns promote ketosis. For example, the Ketoflex 12/3 diet, a form of time-restrictive eating that limits the period during which a person eats to a 12-hour window at least three hours before bedtime, promotes the production of ketones. Watch this clip in which Dr. Dale Bredesen describes this novel dietary protocol and how it improves cognitive function.

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  • Fasting reduces the numbers of circulating monocytes in healthy humans and mice without compromising immune function. www.mountsinai.org
    Fasting Time-Restricted Eating

    Fasting and other forms of caloric restriction are associated with reduced risk of many chronic diseases. Monocytes, white blood cells that play key roles in the body’s immune response, can contribute to the pathogenesis of chronic inflammatory diseases. Findings from a new study demonstrate that fasting reduces the number of circulating monocytes without compromising immune function.

    The authors of the study analyzed blood samples from 12 healthy adults taken at the beginning of the study (baseline), three hours after they ate, and 19 hours after commencing a fast. All the samples were taken at the same time of day (3pm). After fasting, the participants' blood levels of monocytes were markedly lower than after eating. Fasting did not lower blood levels of monocytes below the normal range in people whose baseline levels were already low.

    The study was replicated in mice, with a fasting protocol suitable for rodents. The outcome was similar, with monocytes drastically reduced. A longer fast in the mice yielded even more favorable reductions in monocytes in various tissues as well as reductions in several types of leukocytes, including eosinophils, natural killer cells, and T cells.

    These findings illuminate the role of dietary intake in the regulation of the body’s immune and inflammatory responses and suggest that fasting and other forms of caloric restriction may be viable strategies to reduce inflammation in chronic disease states.

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  • Time-restricted eating may help reduce weight and prevent diabetes and heart disease in people with metabolic syndrome. www.sciencedaily.com
    Fasting Triglycerides Time-Restricted Eating Blood Pressure Dairy Metabolic Syndrome

    More than a third of adults living in the United States have metabolic syndrome, a constellation of conditions that includes abdominal (central) obesity, high blood pressure, high fasting plasma glucose, high serum triglycerides, and low high-density lipoprotein levels. People who have metabolic syndrome are at increased risk of developing diabetes and heart disease. A new study suggests that time-restricted eating may reduce this risk.

    Time-restricted eating is a form of daily fasting that aligns eating and fasting cycles to the body’s innate 24-hour circadian system. People who practice time-restricted eating typically eat during an 8- to 12-hour daytime window and fast during the remaining 12 to 16 hours.

    This study involved 19 adults (average age, 59 years) who had metabolic syndrome. Most of the participants were obese, took a statin or antihypertensive drug, and had poor blood glucose control. They followed a time-restricted eating pattern that allowed them to eat during a 10-hour daytime window with a 14-hour overnight fast for 12 weeks. No overt attempt to change physical activity or diet quality or quantity was required.

    At the end of the study, participants exhibited reduced waist circumference and body fat, lowered blood pressure, and improvements in lipid profiles and blood glucose control. These findings suggest that time-restricted eating may have potential as an adjunct to current therapies to treat metabolic syndrome.

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  • Study demonstrates that exercising before eating breakfast burns more fat, improves insulin sensitivity, & increases glucose uptake into muscle. www.sciencedaily.com
    Exercise Fasting Insulin Time-Restricted Eating Carbohydrates

    Exercise promotes the uptake of glucose into muscle cells and increases insulin sensitivity. Other physical adaptations occur during exercise, as well, including increased muscle mass, decreased fat mass, and improved mitochondrial function. Previous research has demonstrated that training in the fasted state promotes greater glucose tolerance and insulin sensitivity and induces higher fatty acid oxidation compared to training in the fed state. A recent study bolsters these findings, demonstrating that exercising before eating breakfast may enhance some of the beneficial effects of exercise.

    The six-week, single-blind, randomized, controlled trial involved 30 overweight or obese men who engaged in moderate-intensity cycling either before or after eating a high-carbohydrate, mixed-macronutrient breakfast. The men exercised for three, 30-minute sessions the first week and progressed to three, 50-minute sessions over the remaining weeks.

    The men who exercised before eating had nearly 2-fold higher whole-body lipid utilization rates as well as decreased carbohydrate utilization compared to the men who exercised after eating. The effects were sustained throughout the entire six-week study period. These findings suggest that exercising before eating breakfast burns more fat, improves insulin sensitivity, and increases glucose uptake into muscle tissue compared to exercising after eating breakfast. Exercising after eating may blunt these effects, however.

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  • Time-restricted eating may be linked to greater motivation to engage in voluntary exercise. www.sciencedaily.com
    Exercise Fasting Ghrelin Time-Restricted Eating Dairy Weight Loss

    Limiting food intake and engaging in exercise are highly effective strategies for weight loss. People who are obese are often sedentary, however, due to physical limitations and a lack of motivation to exercise. Compelling findings from a new study in mice suggest that ghrelin, a hormone linked to appetite, may increase motivation to engage in exercise.

    Ghrelin, which is produced primarily in the stomach, stimulates appetite, increases food intake, and promotes fat storage in mice and humans. It is often referred to as the “hunger hormone” and is linked to reward-driven behavior. Previous studies have shown that ghrelin administration increases activity in mice in anticipation of food.

    The current study involved mice that were fed on a time-restricted eating schedule (twice daily) versus mice that were allowed to eat freely throughout the day. Both groups of mice ate roughly the same amount of food each day. The mice that were fed on the time-restricted schedule were more motivated to engage in voluntary exercise and ran on an exercise wheel for longer periods. The increase in the animals' activity corresponded to increases in ghrelin levels. Conversely, inhibiting ghrelin attenuated the animals' motivation to exercise.

    Hunger-related behaviors such as increased activity are essential to animals in the wild or human hunter-gatherers because they must forage and seek out or hunt for food. Tapping into these ancient hormonally-driven behaviors may help resolve modern-day concerns of obesity and lack of exercise. However, a small study in humans demonstrated that time-restricted eating decreased morning levels of ghrelin (and subsequently appetite), so more studies on the effects of time-restricted eating and ghrelin in humans are needed.

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  • Time-restricted eating, a ketogenic diet, and exercise improved cognitive function and markers of metabolism in a woman with ApoE4 and Alzheimer's . www.sciencedirect.com
    Alzheimer's Ketosis Fasting Insulin Triglycerides Time-Restricted Eating Metabolic Syndrome Ketogenic Diet

    Time-restricted eating (TRE), a ketogenic diet, and exercise improved cognitive function and markers of metabolism including triglycerides, VLDL, and HbA1c in a 71-year-old woman with ApoE4 that has mild Alzheimer’s disease and metabolic syndrome (case study).

    This is an interesting proof of principle study showing that implementing a nutrition protocol purposed at raising plasma ketones through fasting (TRE) a ketogenic diet and physical exercises can compensate for insulin resistance and the ApoE4 gene in a mild Alzheimer’s patient experiencing cognitive impairment.

    The APOE4 gene is the largest risk factor for Alzheimer’s disease besides age itself.

    To learn more check out this episode highlight of Dr. Dale Bredesen talking about time-restricted eating and a ketogenic diet in the context of Alzheimer’s disease in people with and without ApoE4.

    Episode: https://youtu.be/PWZbeq6MCKU

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  • Early Time-Restricted Feeding Improves Insulin Sensitivity, Blood Pressure, and Oxidative Stress Even without Weight Loss in Men with Prediabetes www.cell.com
    Insulin Resistance Fasting Insulin Time-Restricted Eating Blood Pressure Weight Loss

    A small randomized controlled clinical trial finds time-restricted eating within a 6-hour window (fasting for 18 hours) without reducing calories or losing weight improves insulin sensitivity, beta cell function, blood pressure, oxidative stress and reduces evening appetite.

    All eating was supervised and approached metabolic ward rigor. The improvements in metabolism were independent of weight loss and the reduction in blood pressure was so significant that it was comparable to the standard of care blood pressure medication (ACE inhibitors).

    The time-restricted eating they started early with the first meal at 8 am and dinner before 3 pm. The importance of time of day for this type of intermittent fasting is still an interesting open question, especially since there’s a lot of advocacy for late eating among 16:8 advocates, however, insulin sensitivity usually declines later in the day (and is exacerbated by the production of melatonin, which has an effect of shutting off insulin secretion). Interestingly, Dr. Satchin Panda has been gathering data via his mobile app (my circadian clock) that suggests an eating window later in the day may be comparable to an early eating window.

    To learn more about time-restricted eating and intermittent fasting check out the two separate podcasts I did with Dr. Satchin Panda. The episodes have summaries, timelines, and transcripts!

    Round 2 episode: https://www.foundmyfitness.com/episodes/satchin-round-2

    Round 1 episode: https://www.foundmyfitness.com/episodes/satchin-panda

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  • Young men had increased body fat in response to later meal timing independent of food content and activity level. ajcn.nutrition.org
    Diet Obesity Circadian Rhythm Time-Restricted Eating

    The study found that the timing of food intake relative to melatonin onset, a marker of a person’s biological night, is associated with higher percent body fat. Individuals with high body fat percentages consumed most of their calories shortly before going to sleep when melatonin levels were high, compared to individuals with lower percentages of body fat.

    To learn more about the benefits of time-restricted eating and how to practice it check out my podcasts with Dr. Satchin Panda. To learn more about how late night eating affects cancer risk check out my podcast with Dr. Ruth Patterson. Both podcasts are available on iTunes and YouTube (called foundmyfitness).

    Satchin Panda podcast: https://www.youtube.com/watch?v=-R-eqJDQ2nU Ruth Patterson podcast: https://www.youtube.com/watch?v=8qlrB84xp5g

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  • People that have their deep sleep cycle disrupted for one night experience a 10% increase in amyloid plaque levels. www.sciencedaily.com
    Alzheimer's Sleep Neurons Blue Light Time-Restricted Eating

    People that have their deep sleep cycle (slow-wave cycle) disrupted for one night experience a 10% increase in amyloid plaque levels compared to when their deep sleep cycle is uninterrupted.

    Amyloid beta plaques accumulate outside of neurons in the brain and disrupt synapses (the connections between two neurons that form memories) and is just one way that memory loss occurs in Alzheimer’s disease.

    This study showed that slow-wave sleep, which is the deep sleep that people need to wake up feeling rested, is important for preventing the accumulation of amyloid plaques. While a few nights of disrupted sleep is likely not a problem, it is the chronic disrupted slow-wave sleep (ie. sleep apnea) that may put a person at increased risk for Alzheimer’s disease.

    A few things that I have found improve my sleep are switching all blue lights off before sunset since blue light stops the production of melatonin. I have red lights that turn on before sunset and this has really helped my sleep pattern. Also, a bright light exposure first thing in the morning to start my circadian clock has really helped. Lastly, following a time-restricted eating pattern where I do not eat 4 hours before bed and a cold/quiet room also make a huge difference.

    My podcast with Dr. Satchin Panda discusses the importance of dark/light and food timing in sleep. Dr. Satchin Panda podcast: https://youtu.be/-R-eqJDQ2nU

    My podcast with Dan Pardi also discusses ways to optimize sleep. Dan Pardi podcast: video: https://youtu.be/VhMjrWlWhLU

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  • Late-night eating increases weight gain, raised insulin, fasting glucose, cholesterol & triglycerides in small trial. www.sciencedaily.com
    Insulin Resistance Fasting Circadian Rhythm Fat Insulin Triglycerides Time-Restricted Eating

    A small clinical trial finds that eating later in the day (12 pm to 11 pm) increased weight gain, raised insulin, fasting glucose, cholesterol, and triglyceride levels compared to eating earlier in the day (8 am to 7 pm).

    In the small study, each of the nine healthy weight adults underwent each of the two conditions: daytime eating (three meals and two snacks between 8 a.m. and 7 p.m.) for eight weeks and delayed eating (the same three meals and two snacks eating from noon to 11 p.m.) for eight weeks after a 2-week washout period. This is a small trial and needs to be repeated but is in line with another study that showed when healthy adults eat meals that are identical for breakfast, lunch, or dinner, the postprandial glucose increase is lowest after breakfast and highest after dinner even though the meals were 100% identical.

    For more on meal timing and time-restricted eating…check out my podcasts with the experts, Dr. Satchin Panda and Dr. Ruth Patterson on youtube and iTunes.

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