Browse the evidence

Dietary intake of fermentable fibers and prebiotics boosts the abundance of SCFA-producing bacteria (e.g., Bifidobacteria, Lachnospiraceae), leading to increased production of short-chain fatty acids (SCFAs) which regulate gut homeostasis, immunity, and metabolic health.

To improve your gut health and metabolic markers, focus on eating foods that feed your good bacteria. This means consuming prebiotic fibers found in foods like garlic, onions, bananas, oats, and resistant starches (like cooled potatoes or rice). This fosters bacteria that produce beneficial short-chain fatty acids, which support your gut barrier, immune system, and metabolism. Direct SCFA supplements have shown mixed results in humans, so diet is the primary lever.

Weight loss is the primary therapy for NAFLD, improving liver biochemistry, histology, and insulin sensitivity.

Lose weight through diet and exercise. This is the most effective way to improve liver health in NAFLD patients, even without medication.

Bariatric and metabolic surgery leads to resolution of NAFLD/NASH in the majority of patients and regression of liver fibrosis.

For eligible patients, bariatric surgery is a highly effective treatment that can resolve NAFLD and reverse liver fibrosis.

Habitual consumption of sugar-sweetened beverages (SSBs) causes weight gain and increases the risk of type 2 diabetes, cardiovascular disease, and all-cause mortality.

To prevent age-related weight gain and reduce chronic disease risk, limit or eliminate sugar-sweetened beverages. Replacing SSBs with non-caloric options (water, unsweetened tea/coffee) has been shown to reduce body weight, particularly in individuals with overweight or obesity. Be aware that liquid calories from soda do not make you feel full, so you are likely to consume these calories on top of your normal food intake.

Replacing SSBs with non-caloric beverages reduces body weight and BMI gain, especially in children and individuals with overweight or obesity.

If you want to lose weight or prevent weight gain, swap your sugary drinks for water or unsweetened alternatives. This is particularly effective if you have excess weight. You do not need to eliminate all sugar from your diet, but removing liquid sugar is one of the most impactful single changes you can make.

Wearable activity trackers effectively increase daily physical activity, resulting in an average increase of 1800 steps per day and 40 minutes of walking per day across diverse populations.

Use a wearable activity tracker (pedometer, smartwatch, or fitness app) to increase your daily movement. The device acts as a tool for self-monitoring and goal setting. Evidence shows this intervention leads to an average increase of 1800 steps and 40 minutes of walking per day, regardless of whether you are healthy or have a chronic condition. The key is consistent wear and using the feedback to set goals.

Dietary caloric restriction and regular exercise are effective interventions to reduce inflammation and metabolic dysfunction in obesity, although dietary weight loss alone may be less effective as a long-term anti-inflammatory intervention compared to exercise.

Combine caloric restriction with regular exercise to manage obesity and its associated inflammation. Prioritize exercise for long-term anti-inflammatory benefits, as diet alone may not sustain these effects as effectively over time.

Lifestyle modifications, specifically weight loss of 5-10% combined with regular exercise (150 min moderate or 75 min vigorous per week) and a diet rich in fiber/low in saturated fats and high-glycemic carbohydrates, are the preferred first-line therapy for managing Polycystic Ovary Syndrome (PCOS) symptoms and restoring ovulation.

For PCOS management, prioritize lifestyle changes over medication initially. Aim to lose 5-10% of your body weight through calorie restriction and a diet high in fiber and low in saturated fats and high-glycemic carbs. Incorporate 150 minutes of moderate or 75 minutes of vigorous exercise weekly. This approach is clinically proven to restore regular menstruation and reduce metabolic risks.

A ketogenic diet (KD) improves glycemic control and insulin sensitivity in patients with Type 2 Diabetes Mellitus (T2DM) by reducing carbohydrate intake, lowering serum insulin, and enhancing fat catabolism.

For T2DM patients, adopting a ketogenic diet can significantly lower blood sugar and HbA1c levels compared to standard low-calorie diets. This is achieved by restricting carbohydrates, which lowers insulin levels and improves insulin sensitivity. However, medical supervision is critical, especially if you are taking insulin or SGLT2 inhibitors, to avoid dangerous side effects like hypoglycemia or ketoacidosis.

Lifestyle interventions combining calorie restriction and moderate-intensity exercise are the primary recommended treatment for NAFLD, with weight loss of >7% body weight improving NASH histology and ~10% weight loss leading to fibrosis regression in 45% of patients.

Focus on losing 7-10% of your body weight through a combination of eating fewer calories and doing moderate exercise. This is the most effective way to improve liver health and potentially reverse fibrosis. Even if you don't lose all the weight, regular exercise alone can reduce liver fat.

Insufficient sleep duration (less than 7 hours) disrupts hormonal regulation of appetite by decreasing leptin and increasing ghrelin, leading to increased caloric intake, preference for high-calorie foods, and higher risk of obesity.

Prioritize getting 7-9 hours of sleep. If you are sleep-deprived, you are biologically predisposed to eat more and crave high-calorie foods due to hormonal shifts (low leptin, high ghrelin). Fixing sleep is often more effective for weight management than dieting alone.

African American women with obesity and low insulin sensitivity lose significantly more fat mass and maintain higher total energy expenditure when following a low-carbohydrate diet compared to a low-fat diet.

If you are an African American woman with obesity and have struggled to lose weight on standard low-fat diets, switching to a low-carbohydrate approach (around 20% carbs, 55% fat) may help you lose more fat and keep your metabolism higher. This benefit is specifically linked to having lower insulin sensitivity, which is common in this demographic. Focus on whole foods, complex carbohydrates, and healthy fats while maintaining a caloric deficit.

Lifestyle interventions, specifically calorie-restricted diets combined with at least 150 minutes of weekly aerobic exercise, are the first-line treatment for improving insulin sensitivity in women with PCOS.

Start with lifestyle changes before medication. Focus on eating fewer calories and aiming for 150 minutes of aerobic exercise per week, ensuring at least 90 minutes are vigorous. Prioritize sleep and mental health, as these support metabolic health. If lifestyle changes are too difficult to sustain alone, consider adding insulin-sensitizing drugs like Metformin as a chronic treatment option.

Weight loss of 10% or more through lifestyle interventions (hypocaloric diet and exercise) is necessary to achieve regression of liver fibrosis in patients with NAFL/NASH.

To reverse liver scarring (fibrosis), you need to lose at least 10% of your body weight. This requires a daily calorie deficit of about 750 calories combined with 200 minutes of walking per week. While losing 3-5% helps fat and 5-7% helps inflammation, hitting that 10% mark is what actually reverses fibrosis. This is the most effective treatment available, but it is hard to maintain.

Engaging in brief, sporadic bouts of vigorous-intensity physical activity (VILPA) lasting 1-2 minutes during daily life significantly reduces all-cause, cardiovascular, and cancer mortality in non-exercisers, with effects comparable to structured vigorous exercise.

You do not need to join a gym or set aside large blocks of time for exercise to significantly lower your risk of death from heart disease or cancer. Look for opportunities in your daily routine to move vigorously for just 1-2 minutes at a time. Examples include climbing stairs quickly, walking very fast to catch a bus, or moving briskly between tasks. Doing this 3 times a day (totaling about 4-5 minutes) provides substantial health benefits comparable to structured exercise.

Caloric restriction in humans improves metabolic health by reducing visceral adipose tissue, intramyocellular lipid content, and inflammatory markers, although long-term insulin sensitivity benefits may diminish after two years.

Sustained caloric restriction can reduce visceral fat and inflammation. However, be aware that insulin sensitivity improvements may plateau after two years, and the effort required is high.

Aggressive resistance training is the most effective intervention to offset anabolic resistance and improve muscle mass and function in older adults, especially when combined with adequate protein intake.

Engage in regular, aggressive resistance training and ensure you consume enough protein. This is the most effective way to maintain muscle and metabolic health as you age.

Lifestyle interventions, specifically caloric restriction and exercise, are the foundational first-line treatment for NAFLD, capable of inducing 5-10% weight loss and improving insulin resistance and hepatic steatosis.

Start with lifestyle changes as your primary treatment. Aim for a 5-10% reduction in body weight through a combination of a Mediterranean-style diet (high in plants, healthy fats) and regular exercise (both resistance and aerobic). This is the foundational step recommended by major guidelines before considering medications.

Adhering to specific dietary modifications (smaller portions, low-fat, bland foods) and slow eating habits significantly reduces the frequency and severity of gastrointestinal adverse events (nausea, vomiting, diarrhea, constipation) in patients initiating GLP-1 receptor agonist therapy.

Start with small, bland, low-fat meals and eat slowly. Stop eating when you feel full, not stuffed. This simple behavioral change is the first line of defense against nausea and vomiting when starting GLP-1 medications.

Accumulating up to 10,000 steps per day is associated with a lower risk of all-cause, cardiovascular disease (CVD), and cancer mortality, as well as reduced incidence of CVD and cancer.

Aim for more steps, but don't obsess over hitting 10,000 if it feels like a chore. The research shows significant mortality and disease risk reductions occur well before that number. Focus on increasing your daily average from your current baseline; every 2,000 steps adds benefit, with the curve flattening around 10,000.

Early time-restricted feeding (eTRF), defined as an 8-hour eating window between 06:00 and 15:00, significantly improves insulin sensitivity, reduces fasting glucose, lowers body mass and adiposity, and reduces inflammation in healthy non-obese adults compared to ad libitum eating.

If you are healthy and not obese, try eating all your meals within an 8-hour window that ends by 3 PM (e.g., 7 AM to 3 PM). You do not need to count calories or restrict food types, just the timing. This specific timing window has been shown to improve insulin sensitivity and reduce body fat more effectively than eating later in the day or eating whenever you want.

Physical activity enhances sleep quality in adults, with specific benefits observed in older populations.

Incorporate regular physical activity into your routine to improve sleep quality, which is essential for healthy ageing and overall well-being.

Resistance exercise yields clinically meaningful cognitive improvements in older adults at significantly lower doses (78–679 METs-min/week) compared to aerobic or mixed modalities.

If you are over 50 and want to protect your memory, prioritize resistance training (bands or weights). You do not need to do high volumes of exercise; even low doses (e.g., 15-20 minutes of resistance work a few times a week) can yield significant cognitive benefits, potentially more so than equivalent amounts of aerobic exercise.

Regular moderate-intensity physical activity improves sleep quality and reduces sleep disorders (e.g., insomnia) in adults, with benefits observed across age groups including children and the elderly.

Aim for 30 minutes of moderate-intensity exercise, three times a week. This is the most effective dose for improving sleep quality and managing insomnia. If you are short on time, even 10 minutes of light morning exercise can provide benefits. Avoid high-intensity exercise within 3 hours of bedtime, as it may disrupt sleep.