Browse the evidence

Intermittent Fasting (IF) produces weight loss comparable to continuous caloric restriction, but is generally not recommended for Type 2 Diabetes patients due to hypoglycemia risk.

Intermittent fasting can help you lose weight just as well as counting calories every day. However, if you have Type 2 Diabetes, do not try this without a doctor's supervision due to the risk of low blood sugar.

Intermittent fasting produces weight loss equivalent to daily caloric restriction, with no statistically significant difference in efficacy between the two methods.

If you are overweight or obese, intermittent fasting is a viable weight loss strategy that works just as well as counting calories every day. You can choose a schedule that fits your life (e.g., fasting 2 days a week or eating within a 12-hour window), but expect similar results to traditional dieting. It may be preferable if you find constant daily restriction difficult to maintain.

In overweight and obese adults, higher lean mass in the presence of excess fat mass may benefit metabolic health by increasing resting energy expenditure, potentially offsetting risks associated with high fat mass.

For overweight individuals, building muscle is crucial for metabolic health. Even if you carry extra fat, having more muscle helps burn more calories at rest and may help manage blood glucose levels better than having high fat and low muscle.

Aerobic exercise combined with 16:8 TRE yields greater reductions in body weight and fat mass than resistance training combined with 16:8 TRE.

If you prefer resistance training, adding 16:8 TRE may still help with fat loss, but the additional benefit from TRE appears greater when combined with aerobic exercise. For maximal short-term fat loss with TRE, aerobic exercise may be the more synergistic choice.

In adults, each hour of reduced sleep is associated with a 0.35 unit increase in BMI, suggesting a dose-response relationship.

For adults, losing an hour of sleep per night is associated with a measurable increase in BMI (approx 0.35 units). Prioritizing adequate sleep duration may help maintain a healthy weight.

High levels of physical activity and energy expenditure, such as those derived from cycling as daily transport, act as a protective factor against obesity, although they may be counteracted by high energy-dense diets.

Incorporate daily movement, such as cycling or walking, into your routine to support weight management. However, recognize that exercise alone may not prevent weight gain if your diet consists of energy-dense foods; you must manage both your activity levels and your caloric intake.

Increasing vegetable and fruit consumption contributes to weight stability and may prevent body weight gain, but does not directly cause significant weight loss unless it replaces high-fat or high-energy foods.

To manage your weight, increase your vegetable and fruit intake to help you feel full with fewer calories. However, do not expect to lose weight just by adding them; you must also reduce high-fat or high-energy foods in your diet.

Activation of PPARβ/δ promotes fatty acid oxidation in skeletal and cardiac muscles, preventing obesity and protecting the heart from ischemia-reperfusion injury, particularly in the context of high-fat diets.

Regular exercise, particularly in skeletal and cardiac muscles, may upregulate PPARβ/δ, enhancing the body's ability to burn fatty acids and resist obesity, even with higher fat intake.

Marketplace food portion sizes have significantly increased since the 1970s, exceeding federal standards and contributing to increased caloric intake and obesity.

Be aware that restaurant and packaged food portions have grown significantly since the 1970s, often exceeding federal guidelines. To manage weight, consciously compare your plate to standard serving sizes rather than assuming the entire portion is appropriate for your caloric needs.

Acute cold exposure activates brown adipose tissue (BAT) oxidative metabolism in adult humans, contributing significantly to nonshivering thermogenesis and increasing total energy expenditure.

Exposing yourself to cold temperatures (e.g., 18°C environment) for about 3 hours can significantly boost your energy expenditure by activating brown fat. This happens without shivering, meaning your body burns fuel (glucose, fatty acids, and stored triglycerides) to generate heat. While this is a potent metabolic tool, its effectiveness depends on having active brown fat, which varies between individuals.

Reducing TV viewing time can lead to improvements in BMI, energy intake, and energy expenditure in short-term experimental settings.

If you cut your TV time in half, you will likely eat less and burn more energy, even without starting a new exercise routine. This is a simple lever to pull for weight management.

Alternate-day fasting (ADF) and modified fasting (e.g., 5:2 diet) result in weight loss comparable to continuous energy restriction, with mixed effects on metabolic biomarkers.

If you prefer intermittent fasting, try the 5:2 diet (eating normally 5 days, restricting calories to ~25% on 2 non-consecutive days). It leads to weight loss similar to daily calorie restriction, but may be easier to adhere to for some people. Be prepared for hunger on fasting days.

Significant weight loss (mean 34 kg) achieved via laparoscopic adjustable gastric banding leads to major improvement or resolution of nonalcoholic steatohepatitis (NASH) and hepatic fibrosis in severely obese patients.

For severely obese individuals with fatty liver disease, achieving significant and sustained weight loss is the most effective way to reverse liver damage, including fibrosis and NASH. While lifestyle changes are the foundation, surgical interventions like gastric banding can facilitate the substantial weight loss (often >50% excess weight) required to resolve these conditions, which is difficult to maintain with diet alone.

Obese individuals exhibit a biologically determined posture allocation that results in significantly less standing and movement (NEAT) compared to lean individuals, leading to a daily energy expenditure deficit of approximately 350 kcal.

Focus on increasing non-exercise activity thermogenesis (NEAT) by standing more and sitting less. The study suggests that obese individuals sit ~2 hours more per day than lean individuals. Adopting the standing/movement habits of lean people could burn an extra ~350 calories daily, potentially leading to significant weight loss over a year without changing diet or starting formal exercise.

Whole grains improve gut health by increasing stool weight, accelerating transit, and altering microflora to produce short-chain fatty acids (SCFA) that lower colonic pH and provide immune protection.

Eat whole grains to support your gut health. The fiber in whole grains ferments in the colon to produce beneficial short-chain fatty acids that nourish colon cells and lower pH. This process also increases stool weight and speeds up transit, reducing the risk of colon cancer.

Preoperative carbohydrate loading with iso-osmolar drinks 2-3 hours before anesthesia reduces postoperative insulin resistance and length of stay in major abdominal surgery, and is safe in bariatric patients.

Follow your anesthesia team's instructions on preoperative fasting. Modern ERAS protocols often allow you to drink a special carbohydrate-rich clear fluid up to 2 hours before your surgery. This helps reduce stress on your body and may shorten your hospital stay. Do not eat solid food within 6 hours of surgery.

Bariatric surgery (gastric bypass, banding, gastroplasty) produces substantial weight loss (10-159 kg) and improves comorbidities in patients with extreme obesity (BMI >= 40 or >= 35 with comorbidities).

For those with extreme obesity, bariatric surgery is the most effective way to lose a large amount of weight (10-159 kg) and improve health conditions. It is a major decision with risks, but the benefits are substantial for eligible patients.

Timed food restriction or scheduled meal timing can serve as a potent non-photic zeitgeber to resynchronize peripheral clocks and improve activity rhythms in aged individuals, potentially mitigating age-associated pathologies.

Try eating your meals within a consistent daily window (e.g., 8-10 hours). This regularity acts as a strong time cue for your body's organs, helping to stabilize your sleep and metabolism, especially as you age.

Polarization of physical activity (high-intensity training combined with high sedentary time) may lead to increased health risks despite meeting physical activity recommendations.

If you do intense workouts, do not sit for the rest of the day. Break up sedentary time with light movement to avoid the health risks associated with 'polarization'.

Higher national household availability of ultra-processed foods is positively associated with higher national prevalence of obesity among adults, with each 1% increase in ultra-processed food energy share resulting in a 0.25 percentage point increase in obesity prevalence.

To reduce obesity risk, prioritize unprocessed or minimally processed foods (fruits, vegetables, meats, grains) and limit ultra-processed foods (packaged snacks, sugary drinks, ready meals). National policies should aim to make these ultra-processed options less available and affordable, as their increased presence in households correlates directly with higher obesity rates.

Men may achieve better long-term weight maintenance after VLED-based programs compared to women.

Current evidence suggests men may maintain weight loss better than women after a VLED program, possibly due to higher lean body mass and energy expenditure. However, this is not yet a confirmed rule, and individual results vary widely. Women should not be discouraged, as many do achieve excellent long-term results with proper behavioral support.

Medically supervised high-protein, low-calorie diets (VLCD 500-800 kcal/day or LCD 800-1200 kcal/day) produce equivalent weight loss in obese patients with type 2 diabetes or prediabetes compared to normoglycemic obese patients.

If you have obesity and diabetes or prediabetes, a medically supervised very-low-calorie or low-calorie diet using protein-rich meal replacements can help you lose significant weight (approx. 14% of body weight over a year). This weight loss is just as effective as it is for people without diabetes. Success requires strict adherence to the meal plan, weekly medical check-ins, and gradual introduction of exercise.

Quarantine leads to reduced physical activity and increased sedentary behavior, which rapidly reverses beneficial metabolic and cardiovascular adaptations, leading to insulin resistance, increased blood pressure, and higher cardiovascular risk.

Maintain physical activity through home-based exercises, online classes, or walking in small spaces. Aim to interrupt sedentary time every 30 minutes. Even short bouts of activity add up to weekly recommendations and help prevent the rapid loss of metabolic benefits.

A strict low-carbohydrate diet (approx. 20g carbs/day) in obese patients with type 2 diabetes causes significant weight loss primarily through spontaneous reduction in caloric intake, rather than increased metabolic expenditure or water loss.

If you have type 2 diabetes and are obese, switching to a strict low-carb diet (around 20g carbs/day) for two weeks can help you lose weight. You don't need to count calories or exercise more; your body naturally reduces the amount of food you eat. This leads to fat loss without needing to increase your energy expenditure. Note: This was a short-term study, so long-term effects are not confirmed.