Browse the evidence

High consumption of ultra-processed foods (UPF) in young adult women is associated with a long-term increase in fat mass and a decrease in lean mass by early middle age.

For women, consistently high intake of ultra-processed foods (over 35% of daily grams) in your 20s predicts higher fat mass and lower muscle mass in your late 30s. To mitigate this, prioritize whole foods and minimize UPFs, as they are linked to unfavorable body composition changes over time.

Physical activity increases the competitive advantage of skeletal muscle cells by depleting their stored energy (glycogen/lipids), thereby improving insulin sensitivity and reducing the partitioning of nutrients to fat cells.

Engage in regular physical activity to deplete muscle glycogen and lipids. This forces muscle cells to compete more aggressively for blood nutrients, improving insulin sensitivity and reducing the amount of energy stored as fat. This is more effective than exercise alone for weight loss because it addresses the underlying cellular competition.

Fat cell hyperplasia (increase in number) is the primary competitive strategy of adipocytes, leading to increased partitioning of nutrients to fat and poorer treatment outcomes for weight loss compared to hypertrophy (increase in size).

If you have been obese for a long time, you may have more fat cells (hyperplasia). This makes weight loss harder because each cell competes for nutrients. Consistent physical activity and dietary management are crucial to manage this increased capacity for fat storage.

Intensive weight loss via energy restriction and increased aerobic exercise induces adaptive thermogenesis (reduced resting energy expenditure beyond mass loss predictions) in both male and female physique athletes.

If you are cutting weight for a competition, expect your metabolism to slow down more than your weight loss would predict. This is a normal biological response called adaptive thermogenesis. It is driven by the energy deficit and increased exercise volume. The good news is that this adaptation is temporary and reverses during recovery.

Physical activity alone is an effective strategy for reducing obesity and related comorbidities, particularly abdominal fat, even without dietary energy restriction.

To lose fat, you do not necessarily need to diet. Engaging in 45-60 minutes of moderate exercise daily is sufficient to reduce body mass and abdominal fat. Focus on consistency rather than extreme intensity if you are not restricting calories.

Exercise interventions typically result in less weight loss than predicted by simple energy balance models due to metabolic and behavioral compensation.

Do not be discouraged if you do not lose weight as fast as you calculate. Your body will try to compensate by making you hungrier or moving less. Focus on the health benefits and consistency rather than just the scale.

Long-term intentional weight loss via intensive lifestyle intervention causes greater bone mineral density loss at the hip in men with type 2 diabetes compared to control, increasing frailty fracture risk.

If you have type 2 diabetes and are planning to lose weight, be aware that men may experience greater bone loss at the hip over the long term. To mitigate this, ensure your weight loss plan includes bone-preserving strategies such as resistance training, adequate calcium and vitamin D intake, and regular monitoring of bone density, rather than relying solely on caloric restriction and walking.

High-intensity interval training (HIIT) elicits higher plasma lactate concentrations than work-matched moderate-intensity continuous training (MICT) during the exercise bout.

If you do HIIT, you will produce more lactate than if you did moderate continuous training of the same work. This is expected and part of what drives the unique adaptations.

Obesity is an independent risk factor for severe COVID-19 outcomes, including hospitalization, ICU admission, and mortality, with risk increasing as BMI increases.

Obesity significantly increases your risk of severe illness, hospitalization, and death from COVID-19. Maintaining a healthy weight is a critical protective factor against severe viral infections.

Weight gain after a type 2 diabetes diagnosis is associated with an increased risk of cardiovascular disease events and all-cause mortality.

Avoiding weight gain after a type 2 diabetes diagnosis is important for reducing the risk of heart disease and death. Maintaining a stable weight is associated with better cardiovascular outcomes than gaining weight.

Faster rates of body mass gain (via larger energy surpluses of 5-15%) primarily increase the rate of fat accumulation rather than augmenting strength or muscle hypertrophy compared to maintenance or moderate surpluses.

If your goal is to maximize muscle and strength gains, you do not need a large caloric surplus. A moderate surplus (approx. 5% above maintenance, leading to ~0.5% body weight gain per 2 weeks) is likely just as effective as a large surplus (15%) for muscle growth, while resulting in significantly less fat gain. Focus on progressive resistance training and adequate protein (>=1.8g/kg) rather than overeating.

Viscous fiber supplementation (median dose 8 g/day) leads to modest reductions in body weight and waist circumference in individuals on ad libitum diets, primarily through increased satiety and energy excretion.

If you are not strictly counting calories, adding about 8 grams of viscous fiber daily (found in foods like oats, beans, or supplements) can help modestly reduce body weight and waist size by making you feel fuller and slightly increasing calorie excretion.

During single-joint resistance training, non-recruited muscles undergo significant volume loss (atrophy), particularly when energy and protein intake are low, suggesting a localized reallocation of muscle mass from untrained to trained tissues.

If you are doing targeted resistance training (like arm curls or leg extensions) and not eating enough calories or protein, your untrained muscles may actually shrink. To maximize net muscle gain, ensure your energy and protein intake are sufficient to support the metabolic cost of building new tissue in your trained muscles, preventing your body from cannibalizing untrained muscles for energy.

In adult females aged 19-50, higher pasta consumption (tertiles) is associated with reduced body weight, waist circumference, and BMI compared to non-consumption, whereas no such weight-related benefits are observed in males or older adults.

If you are a woman between 19 and 50, including pasta in your diet is associated with lower body weight and BMI compared to not eating it. You can enjoy pasta as part of a weight-conscious diet.

Dietary energy density and the proportion of hyper-palatable foods are stronger predictors of ad libitum energy intake than macronutrient composition or gut hormone levels.

To control calories, prioritize foods with lower energy density (more volume for fewer calories) and reduce hyper-palatable combinations (high fat/sugar/sodium). These physical properties drive intake more than the specific macronutrient ratios or hormonal responses.

During weight-loss maintenance, a low-carbohydrate diet (20% carbs) increases the estimated energy requirement by approximately 200-300 kcal/day compared to a high-carbohydrate diet (60% carbs), indicating higher energy expenditure on low-carb diets.

If you are maintaining weight loss, switching to a lower carbohydrate diet (around 20% of calories) may increase your daily energy expenditure by roughly 200-300 calories compared to a high-carb diet. This metabolic advantage might make weight maintenance easier without conscious effort.

Greater weight loss during treatment is associated with a lower likelihood of discontinuing GLP-1 RA, and weight regain after discontinuation is associated with a higher likelihood of reinitiating treatment.

Your weight loss progress directly impacts your likelihood of staying on GLP-1 RA. Greater weight loss correlates with better adherence, while weight regain after stopping often prompts patients to restart. If you experience a plateau, discuss it with your provider rather than stopping abruptly, as continued use may still offer health benefits.

Blood pressure reduction from exercise training in MetS patients is conditional on achieving a minimum cumulative exercise duration and lower baseline triglyceride levels.

To lower blood pressure through exercise, you likely need to do more than just 'move'. This study suggests you need to reach a minimum weekly volume (e.g., >100 minutes) and that your baseline triglyceride levels influence how much your blood pressure will drop. If your triglycerides are high, you may need even more volume or different strategies to see BP benefits.

Changes in insulin resistance (measured by HOMA-IR) can be accurately predicted and monitored using serial measurements of body weight and fat mass via the Weight-Fat-Energy (WFE) calculation framework, eliminating the need for direct insulin or glucose testing.

To monitor your metabolic health without blood tests, track your body weight and fat mass daily using a reliable scale (bioimpedance or DXA). Use a mobile app that applies the Weight-Fat-Energy (WFE) model to these serial measurements. The app calculates your 'Rw-ratio' and predicts changes in insulin resistance based on the strong correlation between your body composition changes and metabolic health. This allows you to see the impact of your diet and exercise on your metabolic health indirectly but accurately.

Intermittent Energy Restriction (IER) paradigms, including Intermittent Fasting (IMF) and Time-Restricted Feeding (TRF), produce equivalent weight loss compared to Continuous Energy Restriction (CER) when total caloric intake is matched.

If you are overweight or obese, you can lose weight using Intermittent Fasting (fasting 2-3 days a week or restricting eating to 8-10 hours a day) just as effectively as eating less every single day. The key is that you don't need to restrict calories on your 'fed' days, and most people naturally eat less overall. Focus on consistency with your chosen window rather than perfection, as the total energy deficit matters most.

Obesity is primarily caused by a sustained positive energy balance where caloric intake exceeds energy expenditure, driven by biological, behavioral, and environmental factors.

Focus on creating a sustainable energy deficit through modest dietary changes and increased physical activity, while recognizing that biological and environmental factors may make this challenging. Addressing these factors (e.g., sleep, stress, food environment) is crucial for long-term success.

Weight loss achieved via a very-low-carbohydrate, high-saturated-fat diet does not impair endothelial function (measured by flow-mediated dilatation) and improves other cardiovascular risk markers, refuting the hypothesis that such diets inherently damage vascular health.

If you are overweight and have abdominal obesity, losing weight through a very-low-carbohydrate, high-saturated-fat diet does not appear to harm your blood vessel health (endothelial function) over an 8-week period. In fact, other markers of inflammation and clotting risk improved. The key factor seems to be the weight loss itself, which may counteract the negative effects of high saturated fat intake seen in people who don't lose weight.

Intentional weight loss of >5 pounds in patients with intermittent claudication reduces the annual decline in walking distance, independent of muscle loss.

If you have PAD and are overweight, aim to lose more than 5 pounds. This specific amount of weight loss has been shown to help you walk further for longer, even if you lose some leg muscle in the process. Combine this with exercise for best results.

Low-carbohydrate/high-fat diets (e.g., Atkins) primarily result in weight loss through caloric restriction and water loss, not superior metabolic advantages, and may increase long-term mortality risk if animal proteins and fats are used.

If you choose a low-carb diet, be aware that weight loss is likely due to eating fewer calories and losing water weight, not magic metabolism. Also, be cautious of long-term risks associated with high animal protein/fat intake.