Browse the evidence

Intensive Weight Management Programmes (IWMPs) utilizing Total Diet Replacement (TDR) achieve substantial, sustained weight loss (5-15%) and metabolic improvements in populations with obesity and type 2 diabetes, though specific evidence for women with PCOS is currently insufficient.

For women with PCOS, standard diet and exercise advice often fails to produce lasting metabolic benefits. Intensive programs using meal replacements (TDR) for a few months, followed by a structured return to food, can produce significant weight loss (5-15%) and improve metabolic health. However, because specific studies on PCOS are lacking, this approach should be considered promising but unproven for this specific group, requiring careful monitoring.

Both ketogenic-like (KLD) and ultra low-fat (ULF) diets produce similar weight loss and improvements in insulin resistance when adhered to, regardless of macronutrient composition.

You can lose significant weight and improve insulin resistance on either a very low-carb or a very low-fat diet, provided you stick to it. The specific macronutrient ratio matters less than your ability to maintain the diet and create a caloric deficit. Choose the pattern that allows you to minimize added sugars and refined grains while maximizing vegetables.

SANA (a nitroalkene derivative of salicylate) promotes weight loss and improves glucose management in humans through creatine-dependent thermogenesis, independent of UCP1 and AMPK.

SANA is an experimental drug that appears to trigger weight loss by increasing energy expenditure through creatine-dependent thermogenesis, rather than by suppressing appetite or increasing physical activity. In early human trials, doses of 200-400mg daily led to weight loss and improved glucose control within two weeks with a good safety profile. It works independently of the traditional UCP1 pathway, offering a potential alternative for those who do not respond to other mechanisms. Consult a physician for clinical trials or future availability.

Caloric restriction (CR) and fasting improve cardiac health and mitigate heart failure with preserved ejection fraction (HFpEF) by inducing autophagy, mitophagy, and reducing systemic inflammation.

For HFpEF patients, caloric restriction and fasting regimens (like intermittent fasting) can improve heart function and reduce inflammation. However, these diets are hard to stick to long-term and may cause side effects like muscle loss in some older adults. Because of these challenges, doctors are exploring medications that mimic these benefits without requiring strict dieting.

Caloric restriction mimetics (CRMs) such as SGLT2 inhibitors, GLP-1 agonists, and specific compounds like spermidine and rapamycin can replicate the beneficial effects of caloric restriction on HFpEF without requiring dietary restriction.

If you have HFpEF and struggle with strict dieting, ask your doctor about medications that mimic the effects of fasting. Drugs like SGLT2 inhibitors and GLP-1 agonists, as well as emerging compounds, may help improve heart function and reduce inflammation without requiring you to eat significantly less.

Female powerlifters are more likely than males to restrict energy intake and diet for body composition reasons during competition preparation and competition phases.

Female powerlifters should be aware that they are statistically more likely to restrict energy for body composition. Ensure that caloric restriction does not lead to Low Energy Availability (LEA), which can impair reproductive and skeletal health. Monitor energy intake relative to fat-free mass (aiming for >30-45 kcal/kg FFM/day depending on phase).

Powerlifters increase energy intake on hard training days but do not reduce intake on easier/rest days, prioritizing recovery and muscle growth over caloric deficit on low-volume days.

On easy or rest days, do not automatically slash your calories. Most powerlifters maintain intake to support muscle recovery and growth. Only reduce calories if your specific goal is fat loss and you are managing the deficit carefully, but prioritize recovery needs.

Faster rates of body mass gain may slightly enhance hypertrophy in muscles receiving the greatest training stimulus (e.g., biceps brachii), although the evidence is weak.

While larger surpluses generally lead to more fat gain, if you are heavily training a specific muscle (like biceps), a slightly faster weight gain might offer a marginal hypertrophy benefit. However, this effect is weak and likely outweighed by the fat gain.

Low energy availability (energy deficit) following ACL injury can impair skeletal muscle hypertrophy and recovery, as the body may not have sufficient energy to support both healing and muscle growth.

After ACL surgery, avoid cutting calories to 'stay lean.' Your body needs sufficient energy to heal and rebuild muscle. Focus on eating enough to support your activity level and recovery, rather than restricting food intake.

Female volleyball players are at high risk of Low Energy Availability (LEA), leading to negative health outcomes like menstrual dysfunction and bone loss.

Ensure you are eating enough to fuel your training. If you are feeling constantly tired, missing periods, or getting injured often, you might not be eating enough. Focus on balanced meals with enough carbohydrates, protein, and fats to support your activity level.

GLP-1 receptor agonists and GIP analogs show potential for achieving Type 2 diabetes remission through significant weight loss, but current trial data is limited.

For those with overweight or obesity, GLP-1 and GIP-based medications can facilitate significant weight loss, which is a key driver for Type 2 diabetes remission. While trials are still mapping their long-term efficacy for remission, they represent a promising tool for achieving weight loss goals necessary for reversing the disease.

Time-Restricted Feeding (TRF) without explicit caloric restriction can lead to weight loss and reduced body fat percentage, primarily by reducing the total duration of eating.

If you prefer not to count calories, try eating all your meals within an 8 to 10-hour window each day (e.g., 10 AM to 6 PM). You don't need to restrict what you eat during this window, but you will likely eat less overall because you have less time to eat. This can lead to modest weight loss and reduced body fat.

Long-term dietary interventions (≥12 months) involving moderate macronutrients, low-fat/high-carbohydrate, or high-fat/low-carbohydrate diets all produce significant and comparable weight loss, BMI reduction, and waist circumference reduction compared to a usual diet, with no clinically significant difference between the specific diet types.

If you are overweight or obese, any structured diet that involves active counseling and reduces calories will help you lose weight over the long term (12+ months). Whether you choose high-fat, low-fat, or moderate macronutrients, the amount of weight lost is roughly the same (around 5 kg). Do not waste energy trying to find the 'magic' macronutrient ratio; instead, choose the dietary pattern that fits your lifestyle and preferences so you can stick with it.

High-glycemic load diets lower energy expenditure and increase hunger compared to low-glycemic load or low-carbohydrate diets, even when calorie intake is controlled.

If you feel constantly hungry or have low energy, consider that your diet might be slowing your metabolism. Switching from high-glycemic foods to lower-glycemic options or reducing total carbohydrates may help normalize your energy expenditure and reduce hunger.

During COVID-19 lockdown restrictions, rugby union players experienced a significant reduction in training volume and access to equipment, leading to a mismatch between energy intake and expenditure, with 36% reporting increased total food intake despite reduced physical activity.

If you are an athlete facing a period of reduced training (like lockdown or injury), do not assume your appetite or intake will automatically decrease. The study shows a significant portion of players increased their food intake despite training less. To maintain body composition, you must actively monitor your total food intake and adjust it to match your reduced energy expenditure, focusing on maintaining protein intake to preserve lean mass.

Very-low carbohydrate ketogenic diets (<10% carbs) promote weight loss and improve lipid profiles (lower triglycerides, higher HDL) primarily through energy restriction and ketone body production, rather than macronutrient partitioning alone.

If you choose a ketogenic diet, expect short-term weight loss and improved triglycerides/HDL. However, note that these benefits are largely due to eating fewer calories, not just the lack of carbs. Be aware that this diet excludes many healthy foods like whole grains and fruits, and long-term adherence is difficult.

The holiday season (late November to mid-January) causes significant weight gain in adults, with gains of 0.4 to 0.9 kg that are rarely lost subsequently.

Expect to gain 0.4-0.9 kg during the holidays. This gain is rarely lost later. To prevent this, use self-monitoring strategies like daily weighing or regular check-ins, as these have been shown to mitigate weight gain during this period.

Substituting low- and no-calorie sweetened beverages (LNCSB) for sugar-sweetened beverages (SSB) is associated with lower body weight and reduced risk of coronary heart disease, type 2 diabetes, and mortality, with effects comparable to substituting water for SSB.

If you currently drink sugar-sweetened beverages, switching to low- or no-calorie sweetened beverages (like diet soda or unsweetened iced tea) can help you lose a small amount of weight over time and may lower your risk of heart disease and type 2 diabetes. This benefit is similar to switching to water, making LNCSBs a viable, safe option for reducing sugar intake.

CrossFit-trained athletes typically consume energy and carbohydrates significantly below ISSN recommendations, creating a state of low energy availability that risks health and performance.

If you do CrossFit, you are likely eating too few calories and carbohydrates for your activity level. This can lead to fatigue, poor performance, and health issues like menstrual disorders in women. Aim to increase your carbohydrate intake to at least 5-8 grams per kilogram of body weight daily, and ensure your total energy intake matches your high energy expenditure.

High-energy nutritional supplements combined with exercise training improve functional capacity (6MWT) and fat-free mass index in malnourished COPD patients, but do not consistently improve peak VO2.

If you have COPD and are losing weight or muscle, ask your doctor about high-energy nutritional supplements alongside your exercise program. They may help you walk further and maintain muscle mass, even if they don't always improve your maximum oxygen uptake. Focus on supplements if you are underweight or have lost muscle.

High-volume resistance training (>10 sets per muscle group) performed in a fasted state may benefit from acute carbohydrate supplementation compared to fasting or non-caloric placebo, likely due to glycogen sparing effects.

If you do a very high-volume leg or back session (e.g., 15+ sets) and you train fasted, consider eating carbohydrates before or during the workout. It will likely help you get more reps or sets. If you train fed, or do low volume, you don't need to worry about pre-workout carbs.

In normal weight individuals, both weight loss and weight gain are associated with an increased risk of cardiovascular disease (CVD) compared to weight maintenance.

If you are normal weight, try to maintain your current weight. Both losing and gaining weight were associated with a higher risk of cardiovascular disease compared to staying stable. This may be because weight loss in normal weight individuals can be a sign of underlying illness.

In individuals with obesity, weight gain is associated with a higher risk of cardiovascular disease (CVD) compared to weight maintenance.

If you have obesity, avoiding weight gain is important for cardiovascular health. Gaining weight was associated with a higher risk of CVD compared to maintaining your current weight. Focus on strategies to maintain your current weight.

In older patients with diabetes mellitus, energy intake between 25 and 35 kcal/kg of body weight per day is associated with the lowest all-cause mortality, forming a U-shaped relationship where both lower and higher intakes increase mortality risk.

Older adults with diabetes should aim for an energy intake of 25 to 35 kcal per kilogram of body weight per day. This range is associated with the lowest risk of death. Both eating significantly less than this (leading to potential malnutrition/sarcopenia) and significantly more (excessive nutrition) increases mortality risk. This optimal range may be higher than what is traditionally calculated using standard body weight formulas.