Browse the evidence

Short-Term Fasting (STF) is defined as fasting regimens with a duration of 2–3 days, while Prolonged Fasting (PF) refers to regimens lasting 4 or more consecutive days.

If you fast for 2-3 days, it is Short-Term Fasting (STF). If you fast for 4 or more consecutive days, it is Prolonged Fasting (PF). Choose based on your experience and goals.

Standardized validation protocols, including regular combustion or gas infusion tests, are required to ensure the accuracy and precision of whole-room indirect calorimetry systems for measuring human energy expenditure.

If you are using a whole-room calorimeter, you must validate its performance regularly using traceable standards (like combustion or gas infusion) and report these validation results (accuracy, precision, zero tests) in your publications. This ensures your energy expenditure data is comparable across studies and laboratories.

Bariatric surgery is the most effective long-term treatment for severe obesity, significantly reducing risks of CVD, type 2 diabetes, and adverse pregnancy outcomes, yet access is inequitable due to socioeconomic and structural barriers.

If you have severe obesity and comorbidities, bariatric surgery is the most effective treatment for long-term health. Seek out high-volume centers and ensure your insurance covers the procedure and follow-up care.

A long-term intensive lifestyle intervention (caloric restriction and increased physical activity) does not significantly reduce the prevalence of electrocardiographic left ventricular hypertrophy (ECG-LVH) in overweight or obese adults with type 2 diabetes.

For individuals with type 2 diabetes and obesity, engaging in a long-term intensive lifestyle intervention (diet and exercise) is unlikely to reverse electrocardiographic signs of left ventricular hypertrophy, even if it helps maintain weight loss. While lifestyle changes are crucial for overall health, patients should not expect this specific cardiac structural improvement as a guaranteed outcome of modest weight loss.

Global adult body-mass index (BMI) has significantly increased from 1975 to 2014, with obesity prevalence surpassing underweight prevalence in the majority of countries by 2014.

Global trends show that average body weight has been steadily increasing for decades. This is not a temporary fluctuation but a long-term shift. Public health efforts are currently failing to halt this rise, meaning individual efforts to maintain a healthy weight may face increasing environmental and societal headwinds.

Severe and morbid obesity are increasing globally, with significant regional disparities, particularly in Polynesia and Micronesia.

Severe obesity is becoming more common, especially in certain regions. This is a serious health risk that requires attention and support, not stigma.

An intensive lifestyle intervention focused on weight loss through caloric restriction and increased physical activity does not reduce the rate of major cardiovascular events in overweight or obese adults with type 2 diabetes compared to diabetes support and education.

For people with type 2 diabetes, focusing solely on weight loss through diet and exercise may not be enough to prevent heart attacks or strokes, even if it improves blood pressure and blood sugar. While lifestyle changes are beneficial for overall health and quality of life, they should not be relied upon as the sole strategy for cardiovascular protection in this population without considering other medical interventions.

Global obesity prevalence has increased significantly and now exceeds underweight prevalence in the vast majority of countries, creating a 'double burden' of malnutrition driven by rising obesity rather than persistent undernutrition.

Focus on healthy nutrition transitions that enhance access to nutritious foods. Address the remaining burden of underweight while curbing and reversing the increase in obesity.

Large-volume abdominal liposuction in obese women fails to improve insulin sensitivity, inflammatory markers, or coronary heart disease risk factors, despite significant reduction in subcutaneous fat mass.

Liposuction removes fat but does not fix the metabolic problems associated with obesity, such as insulin resistance or inflammation. If your goal is to improve metabolic health or reduce heart disease risk, liposuction alone is not sufficient; you must achieve a negative energy balance through diet and lifestyle changes to get those benefits.

Transplanting gut microbiota from obese donors to lean recipients can predispose the recipient to greater weight gain, demonstrating a causal role of the microbiome in adiposity.

Your current gut bacteria might be helping you gain weight. While you can't directly swap your microbiome, you can influence it through diet. The paper suggests that weight loss and dietary changes can alter this composition, potentially reducing the efficiency of energy harvest.

Female athletes with Anorexia Nervosa (BMI <16.5) or severe Bulimia Nervosa (purging >4 times/week) should be categorically restricted from sports participation due to high mortality and morbidity risks.

If you are a female athlete with a BMI under 16.5 or purging more than 4 times a week, you are not allowed to compete. This is a categorical restriction based on high mortality risk. Focus on getting help from a multidisciplinary team. Return to play is possible only after significant health improvement and clearance.

AMPK acts as a cellular energy sensor that restores homeostasis by activating catabolic pathways (ATP generation) and inhibiting anabolic pathways (ATP consumption) in response to energy stress.

Your cells have a built-in energy sensor (AMPK) that switches on fat burning and turns off fat storage when energy is low. This happens naturally during fasting or exercise.

Classically activated (M1) macrophages reprogram their metabolism to favor aerobic glycolysis and lactate production over oxidative phosphorylation, leading to TCA cycle interruptions and accumulation of metabolites like citrate and succinate.

When immune cells fight acute threats, they switch to a fast, inefficient energy mode (glycolysis) that produces lactate and specific metabolites. This metabolic shift is a key part of the inflammatory response.

Chemical uncouplers like 2,4-dinitrophenol (DNP) increase energy expenditure but are dangerous and cause severe side effects including hyperpyrexia and death.

Do not use DNP for weight loss. It is a toxin that can cause fatal overheating. The risks far outweigh any potential metabolic benefits.

Calorie restriction (energy deficit) is the primary driver of weight loss, with macronutrient composition having a secondary or negligible impact on long-term outcomes.

To lose weight, you must consume fewer calories than you burn. The specific type of diet (low-carb, low-fat, etc.) matters less for long-term success than maintaining that calorie deficit. Choose a dietary pattern you can sustain that creates this deficit.

Reducing dietary energy density (consuming larger portions of lower-calorie foods) improves satiety and aids weight loss maintenance, regardless of total caloric intake in the short term.

To make your diet easier to stick to, choose foods that are less energy-dense. This means eating more vegetables, fruits, and lean proteins relative to fats and sugars. You can eat larger portions of these foods, which helps you feel fuller for longer, making it easier to maintain a calorie deficit without feeling deprived.

Increasing physical activity (specifically total, light, and moderate-to-vigorous activity) or decreasing sedentary time during a dietary energy restriction intervention is associated with a faster rate of weight loss in women with overweight and obesity.

If you are on a calorie-restricted diet to lose weight, try to stay active or increase your daily movement. This paper shows that people who increased their physical activity (even light activity) or reduced their sitting time lost weight faster than those who became more sedentary. You don't need to start a rigorous gym routine; simply maintaining or slightly increasing your daily steps and reducing sedentary time can help you reach your goal sooner.

Increases in total and moderate-to-vigorous physical activity (MVPA) during the post-weight loss maintenance phase are associated with less weight regain (or greater weight loss) one year after the intervention.

After you reach your weight loss goal, don't stop moving. This study found that people who kept up or increased their moderate-to-vigorous exercise (like brisk walking or jogging) after losing weight were much more likely to keep it off one year later. Treat your post-goal activity as a permanent part of your lifestyle, not just a tool for getting to the goal.

Caloric restriction is the primary and most effective method for weight loss in obesity treatment, regardless of macronutrient composition.

To lose weight effectively, focus on reducing your total daily calories rather than obsessing over specific macronutrient ratios. Aim for a daily intake of approximately 25 kcal per kg of your standard body weight. If you have severe obesity (BMI ≥ 35), start with 20-25 kcal/kg. A modest weight loss of 3-5% of your current body weight is sufficient to improve health risks like high blood pressure and blood sugar. Combine this with behavioral changes like self-monitoring and adequate protein intake to preserve muscle mass.

Aerobic physical activity (30-60 minutes, moderate to vigorous intensity, most days) improves cardiometabolic risk factors and reduces visceral fat, even without significant weight loss.

Aim for 30-60 minutes of moderate to vigorous aerobic exercise most days of the week. This will reduce dangerous visceral fat and improve your blood pressure and blood sugar, even if you don't lose much weight on the scale.

Moderate intensity physical activity (150-250 min/week) prevents weight gain, while >250 min/week is required for weight maintenance after loss.

To keep weight off, aim for more than 250 minutes of moderate exercise per week. To prevent gaining weight, 150-250 minutes is sufficient. Do not rely on exercise alone for weight loss; combine it with dietary changes.

Regular physical activity reduces the risk of colorectal cancer and probably reduces the risk of breast cancer.

Engage in regular physical activity. This is recommended to help reduce the risk of colorectal and breast cancer.

Increased consumption of non-starchy fruits and vegetables is inversely associated with weight gain, with specific subtypes like berries, apples/pears, cruciferous, and green leafy vegetables showing the strongest protective effects against weight change.

To manage weight, focus on increasing your intake of specific fruits and vegetables. Berries, apples, pears, cruciferous vegetables (broccoli, cauliflower), and green leafy vegetables are most effective at preventing weight gain. Be cautious with starchy vegetables like potatoes, corn, and peas, as increased intake is linked to weight gain. Aim for whole fruits rather than juice.

Weight loss of 3-10% of baseline body weight reduces systolic and diastolic blood pressure by approximately 3 mmHg, independent of salt restriction, primarily through decreased sympathetic nervous system activity and improved insulin sensitivity.

If you have high blood pressure and are overweight, aim to lose just 3-10% of your current body weight. You do not need to reach a 'perfect' weight to see benefits; this modest loss can lower blood pressure by about 3 mmHg. Work with a dietitian to achieve this gradually using calorie reduction and behavioral strategies like appetite awareness, rather than crash dieting.