Browse the evidence

Commercial weight loss programs (Atkins, Weight Watchers, Slim-Fast, Rosemary Conley) produce clinically significant weight and fat loss over six months, with no statistically significant difference in final efficacy between the four diets.

Choose a commercial weight loss program that you can realistically adhere to for at least six months. Expect to lose approximately 5-8 kg (11-18 lbs) and 4-5 kg of fat if you stick with it. Do not expect one specific brand (like Atkins or Weight Watchers) to be inherently superior to others in the long run; success depends on your ability to follow the specific rules of the chosen program consistently.

A mobile phone-operated weight-loss program utilizing text messaging for daily weight reporting and immediate tailored feedback significantly improves short- and long-term weight loss and waist circumference reduction compared to no intervention in healthy overweight adults.

To use this method, you need a mobile phone and internet access. Enroll in a program that sends you daily text messages asking for your weight. You will receive immediate, personalized feedback on how much to eat based on your progress. Expect to contact the program frequently (several times a week) initially, as higher contact frequency predicts better weight loss. Adjust your target weight every few months as you progress.

Long-term use of structured meal replacements (one meal and one snack daily) significantly improves weight maintenance and metabolic biomarkers (blood pressure, triglycerides) compared to conventional energy-restricted diets in obese patients.

To maintain weight loss long-term, use a structured meal replacement plan. Replace one meal and one snack daily with fortified shakes or bars, and eat one balanced whole-food meal. This structure reduces decision fatigue and improves metabolic health (blood pressure, triglycerides) more effectively than standard calorie counting alone. Expect to lose about 8% of body weight over 4 years with this approach.

Consuming a diet rich in medium-chain triglycerides (MCTs) for 28 days significantly reduces upper body adipose tissue in overweight men compared to long-chain triglycerides (LCTs).

If you are overweight, replacing some of your long-chain fats (like olive oil or butter) with medium-chain triglycerides (MCTs) may help you lose a bit more upper body fat over a month, provided you keep your overall calories stable. Don't expect miracles; the metabolic boost is real but small. Focus on the quality of your fats, not just the quantity.

VLCDs improve specific medical comorbidities (diabetes, hypertension, hyperlipidemia) more rapidly than LCDs, with some metabolic benefits (e.g., glycemic control in Type II diabetes) persisting even after weight regain.

If you have Type II diabetes or high blood pressure, a VLCD can improve your health markers faster than a standard diet. Crucially, some of these benefits (like better blood sugar control) may last even if you regain some weight, likely due to improved insulin function.

A very low-calorie ketogenic (VLCK) diet (under 50g carbohydrates, 600-800 kcal) is safe and effective for short-term weight loss and glycemic control in type 2 diabetes patients, without causing renal deterioration despite high protein intake.

For a Type 2 Diabetic with obesity, a short-term (4-month) very low-calorie ketogenic diet (under 50g carbs, 600-800 calories) is a safe and highly effective way to lose weight and improve blood sugar control, provided you do not have advanced kidney disease. It is more effective than standard low-calorie diets and does not harm kidney function in the short term. Expect mild side effects like fatigue or headache initially, which usually subside.

High consumption of ultra-processed foods (UPF), defined as >30.8% of total daily energy intake, significantly increases the risk of large weight gain (≥1.68 kg/year) and large waist circumference gain (≥2.42 cm/year) compared to low consumption (<17.8% of energy).

To minimize weight and waist gain, limit ultra-processed foods to less than 17.8% of your daily energy intake. Focus on minimally processed foods, as UPFs are designed to be overconsumed due to low satiety and high energy density, regardless of sugar content.

High consumption of ultra-processed foods increases the risk of incident overweight and obesity (BMI ≥ 25 kg/m²) in individuals who are not overweight at baseline, with a 20% greater risk observed in the highest consumption quartile.

If you are currently normal weight, limiting UPF intake is crucial to prevent future weight gain. High UPF consumption increases your risk of becoming overweight by 20% compared to low consumption.

Adhering to a low-fat vegan diet for 18 weeks significantly reduces body weight, LDL cholesterol, and HbA1c in overweight adults and those with type 2 diabetes compared to no dietary changes.

To lose weight and improve heart health markers, switch to a whole-food, plant-based diet for 18 weeks. You do not need to count calories; focus on eating whole grains, vegetables, legumes, and fruits while avoiding animal products and added oils. The high fiber content helps you feel full sooner, naturally reducing your calorie intake, while the lack of animal fat improves your cholesterol levels.

Higher consumption of ultra-processed foods is associated with greater BMI, waist circumference, and odds of obesity in adults, with a dose-response relationship observed across both sexes.

To reduce obesity risk, prioritize unprocessed or minimally processed foods and actively reduce the proportion of ultra-processed foods in your diet. The study shows a clear dose-response: as UPF intake increases, BMI and waist circumference increase significantly. This is not just about calories; the nature of these foods promotes overconsumption and metabolic disruption.

Consuming low-energy density (low-ED) foods promotes satiety, reduces hunger, and decreases energy intake in the short term, leading to moderate weight loss in long-term studies.

To lose weight, prioritize foods with low energy density, such as those high in fiber and water (vegetables, fruits, legumes) and low in fat. This approach promotes satiety and reduces overall energy intake. While low-fat diets help, combining them with high fiber yields significantly better weight loss results.

Adhering to 60 minutes per day of moderate-to-vigorous aerobic exercise for 12 months significantly reduces body weight, BMI, and total body fat mass in both men and women, even without dietary changes.

To lose weight and body fat without changing your diet, commit to 60 minutes of moderate-to-vigorous aerobic exercise (like brisk walking, cycling, or swimming) 6 days a week. Start slowly over the first 3 months to build up to this duration. This protocol has been proven to reduce weight and fat mass in adults aged 40-75.

Greater increases in physical activity adherence (measured by steps per day, exercise minutes, or VO2max) are associated with greater decreases in weight, BMI, body fat, and intra-abdominal fat.

To maximize fat loss, focus on increasing your daily physical activity over time. Whether through more steps, more minutes of exercise, or improved fitness (VO2max), greater adherence leads to greater fat loss. Start where you are and gradually increase your activity levels.

For overweight and obese adults, low-carbohydrate diets (≤120g carbs/day) produce significantly greater weight loss and greater reductions in predicted atherosclerotic cardiovascular disease (ASCVD) risk compared to low-fat diets (≤30% energy from fat).

If you are overweight or obese, trying a low-carbohydrate diet (limiting carbs to 120g or less per day) may help you lose more weight and improve your heart health risk profile compared to a low-fat diet. This approach works best if you can adhere to the dietary restrictions consistently over several months.

Intentional weight loss of approximately 13% significantly reduces the risk of developing type 2 diabetes, sleep apnea, hypertension, dyslipidemia, and asthma compared to maintaining a stable higher BMI.

If you have obesity (BMI 25-50) and lose about 13% of your body weight intentionally, you significantly lower your risk of type 2 diabetes, sleep apnea, high blood pressure, high cholesterol, and asthma. This benefit is greater than just having a lower BMI without losing weight, suggesting metabolic improvements beyond just mass reduction. Focus on sustainable weight loss strategies like dietary changes and physical activity, as even partial maintenance of loss yields substantial health protection.

Both intermittent calorie restriction (5:2 diet) and low-carb high-fat (LCHF) diets significantly reduce hepatic steatosis in NAFLD patients compared to standard of care, with no significant difference in liver fat reduction between the two specific diets.

To reduce fatty liver, you need to lose weight. You can do this by restricting calories on 2 days a week (5:2 diet) or by eating low-carb/high-fat (LCHF). Both methods work equally well for reducing liver fat if you maintain a calorie deficit. The 5:2 diet may be easier to stick with and has better effects on cholesterol, while LCHF might raise LDL slightly. Choose the one that fits your lifestyle and preferences.

Successful long-term weight loss and maintenance in adults requires a comprehensive approach combining energy restriction (often via fat reduction), regular physical activity, and behavioral strategies such as self-monitoring.

To lose and keep off weight, you must create a calorie deficit, move your body regularly, and track your progress. Focus on reducing fat intake and increasing fiber if possible. Use self-monitoring tools like food and weight diaries. This combination is the most reliable strategy for long-term success.

Continuous self-monitoring via wearable technology (SenseWear Armband) combined with a group-based behavioral weight loss program yields significantly greater weight loss than standard care or the behavioral program alone in sedentary overweight or obese adults.

If you are overweight and sedentary, a weight loss manual alone is likely insufficient for significant results. To maximize your chances, combine a structured behavioral program (like group sessions or coaching) with a wearable activity monitor that provides real-time feedback. The key is continuous, automated self-monitoring of energy balance, which improves adherence and leads to better weight loss outcomes than self-directed efforts or technology alone.

Intermittent fasting significantly reduces BMI and improves glucose metabolism (fasting glucose and HOMA-IR) compared to non-fasting controls in adults without diabetes.

If you are an adult without diabetes, trying intermittent fasting (like time-restricted feeding or alternate-day fasting) for at least 4 weeks can help lower your BMI and improve how your body handles blood sugar, even if you don't lose a massive amount of weight. It may be easier to stick to than daily calorie restriction.

Work-equivalent High-Intensity Interval Training (HIIT) and Moderate-Intensity Continuous Training (MICT) produce comparable reductions in abdominal visceral fat area (AVFA) and total fat mass in obese young women over 12 weeks.

If you are obese and want to lose visceral fat, you can choose either High-Intensity Interval Training (HIIT) or Moderate-Intensity Continuous Training (MICT). The key is to match the total work done (energy expended). If you choose HIIT, you will finish your workout faster, but you will lose the same amount of belly fat as if you exercised for a longer duration at a moderate pace. Ensure you maintain your diet and do not increase your overall daily activity outside of these workouts.

A pre-packaged, nutritionally complete prepared meal plan produces significantly greater long-term weight loss and cardiovascular risk factor improvements compared to a self-selected usual-care diet in overweight/obese patients with hypertension, dyslipidemia, or type 2 diabetes.

If you struggle with the daily effort of planning and cooking healthy meals, a pre-packaged meal plan can help you lose more weight and improve your heart health markers (like blood pressure and cholesterol) compared to trying to manage your diet on your own. The key benefit is the simplicity and structure, which helps you stick with it long-term. Ensure the plan meets your specific caloric needs and nutritional requirements.

A ketogenic diet leads to greater weight loss compared to low-fat diets in patients with overweight or obesity, regardless of diabetes status.

If you are overweight or obese, a ketogenic diet is likely to help you lose more weight than a standard low-fat diet, whether or not you have diabetes. This benefit is consistent across diabetic and non-diabetic groups.

Intermittent energy restriction (IER) produces weight loss and cardiometabolic improvements comparable to continuous energy restriction (CER) over short-term trials (8-24 weeks).

If you are struggling with daily calorie counting, intermittent fasting (like the 5:2 diet) is a valid alternative that yields similar weight loss results. It does not offer a 'magic' advantage in fat loss over standard daily restriction, so choose the pattern that you can stick to consistently.

Long-term lifestyle interventions combining diet, exercise, and behavior therapy significantly reduce the risk of developing type 2 diabetes and metabolic syndrome in adults with impaired glucose tolerance or obesity compared to control groups.

To prevent type 2 diabetes, rely on a combination of dietary changes, regular physical activity, and behavioral strategies rather than just one. Studies show this multi-component approach significantly lowers diabetes risk compared to no intervention or diet alone.