Browse the evidence

A 1-month very-low-calorie ketogenic diet (VLCKD) in women with obesity causes a significant reduction in 24-hour energy expenditure (24hEE) and sleeping metabolic rate (SMR), primarily driven by the loss of lean soft tissue (LST) rather than metabolic adaptation alone.

If you follow a very-low-calorie ketogenic diet, expect your daily calorie burn to drop by about 10% after a month. This isn't just 'metabolic damage'; it's largely because you are lighter and have lost some muscle. To protect your metabolism, prioritize the protein target (1.2-1.5g/kg ideal body weight) and incorporate light resistance or walking to preserve lean tissue.

Intermittent fasting (IF) produces weight loss and metabolic improvements comparable to continuous caloric restriction (CCR) in adults with overweight or obesity, without providing superior benefits.

If you are overweight or obese, intermittent fasting is a viable option for weight loss, but do not expect it to work better than simply eating fewer calories every day. Studies show that IF and continuous calorie restriction lead to similar weight loss (around 5% of body weight) and metabolic improvements over a year. Choose the method that you can stick with long-term, as adherence is key.

Lactobacillus sp. supplementation is safe and well-tolerated in non-comorbid obese individuals, with no significant adverse events reported.

You can take Lactobacillus probiotics with confidence regarding safety. Clinical trials show they are well-tolerated with no significant increase in side effects compared to a placebo.

Increasing exercise volume from 3 sessions/week to 6 sessions/week further reduces fat mass and visceral adipose tissue, although the difference in fat-free mass preservation between 3 and 6 sessions was not statistically significant for absolute fat-free mass kg.

Even 3 days of exercise per week, combined with diet, significantly improves fat loss compared to diet alone. You do not need 6 days to see benefits, but 6 days provides greater fat loss and better muscle preservation.

Higher baseline body weight and BMI strongly predict greater absolute weight loss and fat mass reduction on a very low-calorie ketogenic diet (VLCKD), with men losing significantly more weight than women.

If you have a higher starting weight, you are likely to lose more absolute weight on a VLCKD than someone with a lower starting weight. Men also tend to lose more weight than women on this specific protocol. Use your baseline weight as a predictor of success rather than comparing yourself to others with different starting points.

Flexible time-restricted eating leads to a spontaneous reduction in total energy intake without altering macronutrient composition.

If you use an 8-hour eating window, you will likely eat fewer calories without needing to count them or change your food choices. This spontaneous reduction in energy intake is a key driver of the fat loss seen with flexible TRE.

MBS serves as an effective bridge to other specialty surgeries (joint arthroplasty, hernia repair, organ transplantation) by reducing surgical risks and complications.

If you need joint surgery, hernia repair, or an organ transplant and are obese, getting MBS first can make the other surgery safer, shorter, and less likely to have complications.

Brown adipose tissue (BAT) activity is negatively associated with BMI and body fat percentage; higher BAT activity is linked to lower BMI and body fat, suggesting it plays a protective role against obesity by burning calories.

Increasing brown fat activity through exposure to cold, adequate sleep, and exercise may help counteract the decline in metabolic rate associated with higher body fat. This is a biological lever to support weight management efforts.

Obesity contributes to OSAS pathogenesis by causing upper airway narrowing due to fat deposition in the pharynx and thoracic cavity, reducing vital capacity, and altering ventilation-perfusion ratios.

Losing weight can mechanically open your airway by reducing fat deposition in the neck and pharynx. This is a primary treatment strategy for OSAS, especially if you are overweight.

Increased energy intake, driven by the availability of cheap, energy-dense, ultra-processed foods, is the primary driver of the obesity epidemic, outweighing the contribution of reduced physical activity.

Focus on reducing caloric intake, particularly from ultra-processed, energy-dense foods, as this is the primary driver of obesity. While exercise is beneficial for health, its impact on weight management is secondary to dietary changes in the current food environment.

Bariatric surgery is an effective treatment for severe obesity in adolescents and adults with NAFLD, significantly improving liver histology, fibrosis, and metabolic parameters, but carries risks of complications.

For severe obesity that hasn't responded to lifestyle changes, bariatric surgery is a recommended option that can significantly improve liver health and fibrosis. Discuss the risks and benefits with a specialist, especially if you have advanced liver disease.

Endurance and resistance exercise training lowers plasma BCAA levels and enhances BCAA oxidation, serving as a natural strategy to mitigate BCAA-related insulin resistance.

Engage in regular endurance and resistance training. This naturally lowers circulating BCAA levels and improves their oxidation, helping to counteract insulin resistance. You don't need extreme protocols; consistent training is effective.

Obesity moderates the dose-response relationship for cognitive benefits, with overweight/obese older adults reaching maximal cognitive benefits at lower exercise doses (~600 METs-min/week) than those with healthy BMI.

If you are overweight or obese, you may achieve maximum cognitive benefits with around 600 METs-min of exercise per week. Pushing beyond this may not yield additional cognitive gains and could be unrealistic. Start with moderate doses.

Intermittent fasting and time-restricted feeding activate AMPK and improve health outcomes by mimicking some benefits of caloric restriction without necessarily reducing total calories.

Try eating all your meals within a restricted window of time each day (e.g., 8 hours). This activates AMPK, a key energy sensor, which can improve health and function even if you don't count calories.

Long-term caloric restriction (25% reduction) slows the pace of biological aging as measured by DunedinPACE in healthy adults, though it does not significantly alter static biological age estimates from PhenoAge or GrimAge clocks.

If you can sustain a moderate calorie deficit (even around 10-15%), it may slow the rate at which your body ages biologically, as measured by specific epigenetic markers. This does not necessarily reverse your current biological age, but it may slow the accumulation of age-related damage. Consistency over two years is key, and behavioral support helps maintain the deficit.

Diet order effects on energy balance and body composition are not observed when comparing Ultra-Processed Foods (UPF) to Minimally Processed Foods (MPF) if the diets are matched for macronutrients, energy density, and fiber.

When comparing ultra-processed foods to minimally processed foods, the physical properties of the food (energy density, fiber, volume) matter more than the processing status itself for determining intake. In this study, when UPF and MPF were matched for these properties, there was no difference in weight loss or energy intake based on which diet was eaten first. This suggests that formulating UPF to match the fiber and density of whole foods may mitigate overeating behaviors.

GLP-1 receptor agonists do not significantly increase energy expenditure in humans, despite evidence in animal models.

Don't expect GLP-1 drugs to burn extra calories at rest. They work by reducing food intake.

Supervision has a trivial and statistically non-significant impact on body composition outcomes (body fat %, fat mass, fat-free mass) compared to unsupervised training.

Do not expect a coach to help you lose fat or gain muscle mass more than you would on your own, provided you follow the program. Focus on consistency and progressive overload. Supervision is more valuable for learning complex lifts and maximizing strength than for changing body composition.

In healthy adults, total energy expenditure (TEE) is a repeatable, durable trait that is not associated with short-term changes in body weight or body composition, meaning low TEE is not a risk factor for weight gain and high TEE is not protective against fat gain.

Stop blaming your weight on a 'slow metabolism.' This study shows that in healthy adults, metabolic rate is a stable trait and does not predict who gains weight or fat. Whether you burn calories fast or slow, it doesn't inherently protect you from or cause you to gain fat. Focus on the net energy balance (what you eat vs. what you move) rather than trying to 'boost' your metabolism, as your baseline expenditure is likely fixed and repeatable.

Bariatric surgery is the most effective intervention for reducing epicardial fat volume and improving HFpEF outcomes, superior to modest lifestyle changes.

For obese HFpEF patients, bariatric surgery is the most effective way to reduce epicardial fat and improve heart function. It reduces EAT more effectively than modest lifestyle changes. Consult with a bariatric specialist to see if you are a candidate.

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.