Browse the evidence

Predictive equations for Resting Energy Expenditure (Mifflin, Harris-Benedict, Derumeaux, WHO) significantly overestimate individual REE in adolescents with severe obesity, rendering them clinically unreliable for prescribing specific caloric deficits.

Do not rely on standard online calculators or clinic formulas to determine your daily calorie limit if you are an adolescent with severe obesity. These tools often overestimate your energy needs by a significant margin (sometimes nearly double), leading to failed weight loss or unhealthy restriction. Focus on sustainable lifestyle habits and professional guidance rather than precise calorie counting based on these flawed estimates.

Intermittent diet breaks (one week of energy balance every two weeks) during a 25% energy deficit do not improve body composition or resting metabolic rate compared to continuous energy restriction in resistance-trained females.

If you are a resistance-trained woman, taking one-week diet breaks every two weeks during a 25% calorie deficit will not help you lose fat or preserve muscle any better than dieting continuously for the same total time in deficit. You can use breaks if you psychologically need them, but do not expect them to save your metabolism or muscle mass compared to sticking to the deficit continuously.

In adults with type 2 diabetes, behavioral weight loss interventions do not significantly reduce the long-term risk of cardiovascular disease events or all-cause mortality compared to standard care.

For people with type 2 diabetes, relying solely on behavioral weight loss interventions (diet and exercise) may not be enough to prevent cardiovascular disease or death in the long term. While weight loss is still recommended for other benefits like diabetes remission, patients should discuss comprehensive cardiovascular risk management, including medications with proven cardiovascular benefits, with their healthcare provider.

A small change approach (SCA) consisting of a 2000-step daily increase and 100 kcal daily reduction does not prevent long-term weight gain in adults with overweight or obesity compared to monitoring alone over 2-3 years.

If you have overweight or obesity, simply adding 2000 steps and cutting 100 calories a day is unlikely to keep your weight off in the long run (2+ years). While you might see some benefit for the first year, it eventually fades to being no better than just having your weight checked regularly. For long-term management, you likely need more than just these small, isolated changes.

Switching from a healthy low-fat diet to a healthy low-carbohydrate diet (or vice versa) after 6 months of weight loss does not result in renewed or accelerated weight loss compared to continuing the initial diet.

If you hit a weight loss plateau after 6 months, simply switching from a low-fat diet to a low-carb diet (or vice versa) is unlikely to restart weight loss. The body's physiological response to weight loss (slower metabolism, increased hunger) persists regardless of the specific macronutrient composition of a 'healthy' diet. Focus on maintaining the deficit and behavioral adherence rather than expecting a diet switch to magically overcome the plateau.

BMI is an inadequate measure of obesity because it does not distinguish between lean muscle mass and adipose tissue, leading to misclassification of metabolic health.

Don't rely on BMI alone. If you have a normal BMI but feel unwell, ask about waist circumference and metabolic health. If you have a high BMI but are muscular, focus on metabolic markers rather than just weight.

When subcutaneous white adipose tissue (scWAT) reaches its maximal storage capacity, it becomes dysfunctional and fails to store lipids appropriately, leading to ectopic fat accumulation in the liver and visceral depots, thereby causing non-alcoholic fatty liver disease (NAFLD).

If you are obese, your body's ability to store fat safely in your subcutaneous areas (like thighs and arms) may be maxed out. Once this 'buffer' is full, excess fat spills over into your liver and visceral organs, causing disease. Strategies to improve metabolic health should focus on preventing this overflow, potentially through interventions that support adipose tissue health or reduce caloric intake to match storage capacity.

Reduction of adipocyte-derived SPARC protects against high-fat diet-induced obesity and metabolic dysfunction in female mice by enhancing energy expenditure and lipolysis.

This research identifies SPARC, a protein elevated in obesity, as a key regulator of fat storage. Reducing SPARC (naturally via caloric restriction or potentially via future therapies) may help manage weight by increasing energy expenditure and breaking down fat, particularly in women. While not a direct diet advice, it highlights that lowering this specific protein is linked to improved metabolic health.

Pharmacological activation of brown and beige adipose tissue thermogenesis via beta-3 adrenergic signaling or UCP1-independent futile cycles increases energy expenditure and improves systemic metabolic health.

Your fat tissue is not just storage; it actively regulates your metabolism. While cold exposure can activate brown fat, current medical strategies focus on pharmacological agents (like GLP-1 agonists) that may indirectly support metabolic health. Understanding that visceral fat is metabolically harmful while subcutaneous fat is more neutral can guide lifestyle choices, but surgical removal of fat is not a cure for metabolic disease.

Counter-regulatory mechanisms, specifically adaptive thermogenesis and increased eating drive, are potent physiological responses to weight loss that actively promote weight regain, thereby limiting the long-term efficacy of lifestyle interventions and pharmacotherapies.

When you lose weight, your body fights back by lowering your metabolic rate and increasing hunger. This is a normal biological response, not a personal failure. To maintain weight loss, you must anticipate this metabolic adaptation and likely require ongoing, structured support rather than relying on initial willpower alone.

Global Positioning Systems (GPS) and metabolic power calculations tend to underestimate energy expenditure during soccer match-play compared to indirect calorimetry, particularly during recovery phases.

Be cautious when using GPS devices to estimate calorie burn. They often underestimate energy expenditure, especially during rest periods in soccer. Use this data as a rough guide rather than an exact number when planning nutrition.

In strength-trained individuals, acute carbohydrate intake does not improve resistance training performance (repetitions to failure or total volume) when compared to a fed state with a 2-5 hour post-prandial window, provided the workout volume is moderate (≤10 sets per muscle group).

If you eat a normal meal 2-5 hours before lifting, you do not need to force-feed yourself carbohydrates right before training to get better reps or strength. Your muscles have enough glycogen. Save the carbs for post-workout or general daily intake. If you train fasted or do extremely high volume (>10 sets/muscle), then carbs may help, but for standard sessions, don't stress about pre-workout carbs.

Bariatric surgery reduces all-cause and cardiovascular mortality and heart failure incidence, but its effect on reducing *incident* atrial fibrillation is not statistically significant.

Bariatric surgery significantly reduces death and heart failure in obese patients, but it does not significantly reduce the risk of *developing* new atrial fibrillation. It is still beneficial for overall heart health.

Ketogenic diets (KD) do not independently reduce energy intake or increase energy expenditure compared to non-ketogenic diets when energy density and behavioral factors are controlled; any observed weight loss is attributable to caloric deficit rather than ketosis itself.

If you are choosing a diet for weight loss, know that a ketogenic diet is not metabolically superior to a high-carbohydrate diet in terms of appetite control or energy expenditure. You will lose weight on either diet if you maintain a caloric deficit. Do not expect ketones to magically suppress your hunger or boost your metabolism beyond what is achieved by simply eating fewer calories.

Rapid and substantial weight reduction, such as that achieved by bariatric surgery or certain medications, may result in greater reductions in lean muscle mass compared to gradual weight reduction.

If you are undergoing rapid weight loss (e.g., surgery or strong medications), prioritize resistance training and adequate protein intake to protect your muscle mass. Monitor your body composition, not just scale weight, to ensure you are losing fat, not muscle.

Hepatic protein kinase Cbeta (PKCβ) deficiency mitigates late-onset obesity in mice by increasing energy expenditure through β3-adrenergic receptor signaling, independent of FGF21.

This research suggests that as we age, our liver may produce more PKCβ, which can suppress our body's ability to burn fat and heat (thermogenesis). While you cannot change your genetics, maintaining liver health through regular physical activity—which is shown to repress PKCβ expression—may help preserve your metabolic rate and resistance to age-related weight gain.

Increasing resistance training volume from moderate (3 sets/exercise) to high (5 sets/exercise) does not improve lean mass or muscle thickness preservation during a moderate caloric deficit in trained males.

If you are dieting to lose fat but want to keep your muscle, you do not need to drastically increase your training volume. A moderate volume (e.g., 3 sets per exercise) is just as effective as high volume (5 sets) for preserving muscle mass, provided you are eating enough protein (approx. 2.8g/kg FFM) and maintaining a moderate caloric deficit. Focus on keeping weights heavy (close to failure) rather than adding extra sets.

Energy-restricted diets have limited efficacy in reducing body fat and preventing cardiovascular events in T2DM compared to metabolic surgery or newer pharmacological interventions.

While healthy eating is crucial for T2DM, energy-restricted diets alone may not significantly reduce body fat or prevent heart problems in the long term. Combining diet with newer medications that target fat loss may be more effective.

Obesity severity (Class I, II, III) is directly correlated with increased direct medical costs, with Class III obesity costing up to 3.3 times more than normal weight individuals.

Higher obesity classes (II and III) are associated with significantly higher medical costs (up to 3.3x normal weight). This highlights the economic urgency of addressing obesity, especially in higher severity classes, through early intervention.

High host-driven digestibility (HDD) diets, such as ultra-processed foods, decouple host and microbial nutrient status by maximizing small intestinal absorption, which leads to host energy surplus and gut microbial nutrient limitation.

To optimize gut health and metabolic balance, prioritize foods with low host-driven digestibility (high fiber, resistant starch, whole foods). These foods escape small intestinal absorption, reaching the colon to feed beneficial microbes, which in turn produce short-chain fatty acids that support host health. Ultra-processed, high-digestibility foods absorb quickly, leading to host energy surplus and starving the gut microbiome.

Body Mass Index (BMI) is a major confounder in studies linking macronutrient intake to mortality, and its exclusion from multivariate analysis in the PURE study is questionable.

When evaluating studies on diet and health, check if BMI was included as a confounder. Its absence may skew results, as BMI is strongly linked to both diet and mortality.

Bariatric surgery significantly reduces the incidence of obesity-associated cancers and cancer-specific mortality compared to non-surgical controls.

For individuals with morbid obesity, bariatric surgery is a highly effective intervention for reducing cancer risk. Discuss surgical options with a specialist if lifestyle changes are insufficient.

High cardiorespiratory fitness (CRF) mitigates or eliminates the 'obesity paradox' in heart failure, meaning overweight patients with high CRF do not have better survival than normal-weight patients with low CRF.

For heart failure patients, being overweight is not inherently protective if you are unfit. High cardiorespiratory fitness (CRF) is the key determinant of survival. Focus on improving your fitness through exercise (like the 6-minute walk test or CPX) rather than just focusing on BMI, as high fitness eliminates the 'obesity paradox' survival advantage.

High intake of dietary fructose (common in Western diets) metabolically rewires innate immunity by increasing mTORC1 activity and IL1B expression in monocytes/macrophages, thereby promoting a pro-inflammatory state and reducing metabolic flexibility.

If you consume a diet high in processed foods containing corn syrup or high-fructose ingredients, you may be inadvertently keeping your immune system in a state of low-grade alert. This happens because fructose pushes immune cells to prioritize inflammatory signaling over metabolic flexibility. Reducing processed fructose intake can help restore normal immune metabolic function.