Browse the evidence

Both volumetric dieting (energy density ≤ 1.5 kcal/g) and time-restricted eating (8-hour window) produce equivalent reductions in body weight and fat mass while preserving lean body mass in middle-aged, physically active adults over 12 weeks.

If you want to lose fat and keep muscle without changing your exercise routine, you can choose either to eat lower-energy-density foods (more volume, fewer calories per gram) or to eat all your calories within an 8-hour window. Both methods worked equally well in this study. Choose the one you can stick to consistently, as adherence was higher for the time-restricted eating group.

Intermittent severe caloric restriction (3 days/week, 600-800 kcal) combined with habitual intake on other days for 6 weeks produces significant weight loss primarily from android fat mass while preserving fat-free mass and maintaining metabolic health in active athletes.

If you are an active athlete needing to lose weight, try restricting calories to 600-800 kcal on 3 alternating days (e.g., Mon/Wed/Fri) while eating normally on the other 4 days for 6 weeks. This method preserves muscle better than daily dieting and is easier to stick to socially. Ensure you are eating enough protein on non-restriction days to support your training.

Multicomponent lifestyle interventions (diet, exercise, behavioral strategies) are recommended for all women with PCOS and excess weight to achieve 5-10% weight loss, which significantly improves hormonal outcomes, insulin resistance, and quality of life.

If you have PCOS and carry extra weight, start with a plan that combines better eating, regular movement, and behavioral strategies like tracking your progress. Aim to lose just 5-10% of your body weight over six months; this small change significantly improves your hormones, insulin resistance, and how you feel. Work with a provider who respects your individual preferences and avoids weight stigma.

Vigorous exercise is more effective than moderate exercise for reducing subcutaneous fat and improving body composition, even when total energy expenditure is lower.

Don't worry about staying in a 'fat burning' low-intensity zone. Vigorous exercise can lead to greater fat loss even if you burn fewer total calories than a long, slow walk, likely due to metabolic after-effects.

Dietary interventions during pregnancy significantly reduce maternal gestational weight gain and lower the risk of pre-eclampsia, gestational diabetes, and preterm delivery compared to control groups.

Adopt a balanced diet focusing on whole grains, fruits, vegetables, and lean proteins while limiting fat to 30% of calories. This approach, managed by dietetic professionals, effectively reduces excessive weight gain and lowers risks of serious pregnancy complications like pre-eclampsia and gestational diabetes without harming the baby's growth.

Intentional weight loss in overweight individuals with type 2 diabetes is associated with a significant reduction in total mortality and cardiovascular disease mortality.

If you have type 2 diabetes and are overweight, aiming for a moderate, intentional weight loss of 20-30 pounds is associated with significantly lower risk of death from heart disease or diabetes. Avoid extreme weight loss (over 70 pounds) as it may carry higher risks. Focus on sustainable, intentional changes rather than rapid or unexplained weight changes.

Wearable activity trackers lead to improvements in body composition, specifically bodyweight and waist circumference, with large effect sizes for bodyweight reduction.

Using a wearable activity tracker can help you lose weight, with an average reduction of 0.5 to 1.5 kg. This benefit is seen in both healthy adults and those with chronic conditions like diabetes or heart disease. The weight loss is a result of the increased physical activity driven by the tracker.

Higher daily step counts (specifically >5,000 to >12,500 steps) are associated with a lower prevalence of metabolic syndrome and cardiometabolic risk factors in cross-sectional studies.

Aiming for more than 5,000 steps a day is associated with a lower risk of metabolic syndrome. Reaching 12,500 steps offers even greater protection against cardiometabolic risks, according to large population studies.

Nutritional supplementation promotes weight gain and improves fat-free mass, 6-minute walk distance, and quality of life in undernourished COPD patients, with maximal benefits when combined with exercise.

If you have COPD and are losing weight or have low muscle mass, nutritional supplements are recommended. Focus on high-protein, high-fat oral supplements taken in small, frequent portions throughout the day rather than large meals. This strategy helps overcome the breathlessness associated with eating large volumes and supports muscle maintenance. Combining this with exercise may yield the best functional results.

Intentional weight loss, particularly through bariatric surgery or significant lifestyle changes, reduces the risk of obesity-associated cancers, including endometrial and breast cancer.

If you are obese, losing weight can significantly lower your risk of endometrial and breast cancer. Even a modest loss of 20 pounds or more has been shown to reduce risk. Bariatric surgery, for those eligible, offers even greater protection.

In short-term trials (≤16 weeks), increasing physical activity expressed as weekly energy expenditure is positively related to reductions in total adiposity in a dose-response manner.

If you want to lose fat using only exercise, you must burn a significant amount of calories (around 3000 per week) over a short period (under 4 months). This typically means walking 45-60 minutes at a moderate pace most days. Do not expect this to work well or be sustainable over many months, as the dose-response relationship disappears in long-term studies.

Obesity and high-fat diets impair male fertility by increasing oxidative stress, reducing sperm concentration, motility, and DNA integrity, while moderate exercise and healthy diets (e.g., Mediterranean) can improve these parameters.

Maintaining a healthy weight through a balanced diet (like the Mediterranean diet) and regular moderate exercise can improve sperm quality by reducing oxidative stress. Avoid high-fat diets and sedentary behavior.

Weight loss, achieved through lifestyle modifications (diet, exercise) or bariatric surgery, significantly improves or resolves Obstructive Sleep Apnea (OSA) and its associated metabolic derangements.

Losing weight is the most effective way to treat OSA. This can be done through lifestyle changes (diet and exercise) or, if those fail, through bariatric surgery. Both methods significantly improve OSA symptoms and metabolic health. If you have OSA, prioritize weight loss as a primary treatment strategy alongside or instead of just using CPAP.

Diet-induced weight loss of approximately 10% of body weight significantly improves hepatic steatosis, necroinflammation, and insulin resistance in patients with NAFLD/NASH, with histological improvement correlating with the magnitude of weight loss.

To improve your liver health, aim to lose about 10% of your current body weight through a caloric deficit. This can be achieved via low-fat or low-carbohydrate diets, as both show benefit. Consistency is key; even losing 5-7% helps, but 10% yields the best histological improvements. Combine this with moderate exercise (like walking 40 minutes, 3-4 times a week) for synergistic benefits on insulin sensitivity and visceral fat.

Ultra-endurance athletes should consume 30 to 70 g of liquid carbohydrates per hour during exercise to maintain blood glucose oxidation and delay fatigue.

During long events (>6 hours), drink 30-70 grams of carbohydrates per hour. Use liquid forms (sports drinks) rather than solids to avoid stomach issues. This helps keep your blood sugar stable and delays fatigue.

Replacing seated computer work with walking-and-working on a vertical workstation significantly increases energy expenditure (by ~119 kcal/h) in obese individuals, potentially leading to substantial annual weight loss if sustained.

If you have obesity and sit at a computer all day, try replacing 2-3 hours of sitting with walking on a treadmill desk. This simple change can burn an extra ~120 calories per hour. Over a year, this could theoretically lead to significant weight loss (20-30 kg) without changing your diet, provided you stay consistent. Start with a slow walking speed and adjust as needed.

Discontinuation of physical exercise during confinement is associated with weight gain, whereas maintaining or starting exercise is associated with weight loss.

Keep exercising or start moving if you haven't. Stopping exercise is linked to gaining about 1 kg, while continuing or starting helps you lose nearly 1 kg during confinement.

High intake of refined grains, sweets, desserts, and refined bread is associated with increased weight gain and larger increases in waist circumference.

Limit refined grains, white bread, sweets, desserts, and sugar-sweetened beverages. These are linked to weight gain and increased waist circumference. Replace them with whole grains, fruits, and vegetables.

Increasing fruit and vegetable consumption without substituting other foods leads to a small but significant reduction in body weight (approx. 0.68 kg) and does not increase energy intake in the short term.

To manage weight, simply increase your daily fruit and vegetable intake by about 133 grams (roughly one to one-and-a-half extra portions) without worrying about cutting out other foods. Over a few months, this addition is associated with a small but statistically significant weight reduction (approx. 0.7 kg) compared to not increasing intake, without requiring you to restrict other food groups.

Frequent fast food consumption (more than once per week) is directly associated with higher BMI and a significantly increased risk of obesity in Mediterranean adults.

If you eat fast food more than once a week, you are statistically more likely to have a higher BMI and be obese. To mitigate this, reduce the frequency of fast food consumption or compensate by reducing energy intake from other sources, as fast food is energy-dense and often displaces healthier options.

Postoperative exercise following bariatric surgery is associated with a greater degree of weight loss (mean difference of 4.2% total BMI loss) at 12 months compared to no exercise.

If you have had bariatric surgery, aim for at least 30 minutes of moderate exercise, like walking, at least three days a week. This habit is associated with losing about 4% more of your total body mass index compared to not exercising. Start with walking, as it is safe and effective.

Intentional weight loss (5-10% of body weight) through combined diet and exercise improves metabolic health, reduces inflammation, and decreases the incidence of CMS in older adults.

If you are older and overweight, aim for a modest 5-10% weight loss through a combination of healthy eating and regular exercise. This can significantly reduce your risk of heart disease and diabetes without necessarily causing harmful muscle loss if you include strength training.

Obesity is primarily driven by a caloric surplus resulting from a Westernized diet high in fats and sugars combined with reduced physical activity, leading to increased morbidity and mortality risks for type II diabetes, hypertension, and cardiovascular disease.

Focus on reducing intake of Western-style foods (high fat/sugar) and increasing daily physical activity. This combination is the primary lever for preventing and treating obesity and its associated diseases like diabetes and heart disease.

Vigorous aerobic exercise (≥3 days/week, 30+ min, ≥60% VO2max) and combined resistance training improve insulin sensitivity and androgen levels in adolescents with PCOS.

Teens with PCOS should aim for at least 3 days of vigorous aerobic exercise (keeping heart rate at 60% of max) and 3 days of strength training per week. This combination is more effective for improving androgen levels than exercise alone.