Browse the evidence

Hypocaloric diets reduce the secretion of leptin, TNF-alpha, IL-6, and IL-8 from adipose tissue, but do not alter the secretion of adiponectin or PAI-1, regardless of whether the diet is low-fat/high-carbohydrate or moderate-fat/moderate-carbohydrate.

If you are obese and lose weight through a caloric deficit, your body will likely reduce the secretion of leptin and inflammatory cytokines (TNF-alpha, IL-6, IL-8) from fat tissue. However, do not expect your adiponectin or PAI-1 secretion from fat tissue to change with moderate weight loss. The specific type of diet (low-fat vs. moderate-fat) matters less than the total calorie reduction for these specific markers.

Intermittent fasting (IF) regimens produce weight loss results statistically similar to traditional Caloric Energy Restriction (CER).

You can achieve the same amount of weight loss with intermittent fasting as you can with standard calorie counting. Choose the method that you can stick to long-term.

Physical activity is significantly more effective for maintaining weight loss after achievement than for producing initial weight loss.

Use diet to lose the weight and use exercise to keep it off. While exercise has health benefits, it is less effective than dietary changes for initial weight loss. Focus on creating a caloric deficit through food first, then use moderate activity (like 1 hour of brisk walking daily) to maintain your new weight.

Meal replacement diets significantly reduce oxidative stress (measured by urine lipid peroxides) during weight maintenance compared to food-based diets, independent of the magnitude of weight loss.

If you are concerned about long-term health markers like oxidative stress, a structured meal replacement diet may offer additional benefits beyond just weight loss, specifically in reducing oxidative stress markers during the maintenance phase.

Weekend lifestyle patterns, specifically higher dietary intake and lower physical activity, cause weight gain or cessation of weight loss, thereby hindering long-term weight management efforts.

To lose weight effectively, you must maintain your weekday dietary and activity habits on weekends. The study shows that even small daily caloric surpluses on Saturdays and Sundays can completely halt weight loss or cause weight gain, negating the deficit created during the rest of the week. Treat weekends as part of the intervention, not a break from it.

Consuming 2.56 mg of capsaicin with every meal during a negative energy balance prevents the typical reduction in resting energy expenditure and diet-induced thermogenesis, thereby supporting fat oxidation without increasing blood pressure.

If you are dieting, adding a specific amount of capsaicin (approx. 2.56 mg per meal, found in about 1 gram of red chili pepper) to your meals may help maintain your metabolic rate and burn more fat, without raising your blood pressure. This strategy works best if you are already used to eating spicy foods and are in a caloric deficit.

Roux-en-Y gastric bypass surgery induces significantly higher postprandial energy expenditure and 24-hour total energy expenditure compared to vertical banded gastroplasty (VBG) in weight-stable patients, despite similar body composition and caloric intake.

This research suggests that Roux-en-Y gastric bypass surgery alters metabolism to burn more calories after meals compared to other restrictive surgeries like VBG, even when patients eat the same amount and have similar body composition. This increased energy expenditure may be a key reason why gastric bypass leads to better long-term weight loss maintenance. For non-surgical approaches, mimicking these metabolic changes (e.g., through gut hormone modulation) could be a promising strategy.

Caloric restriction (30-40% reduction) extends mean and maximal lifespan and delays age-related diseases in nonhuman primates, suggesting similar effects in humans.

Caloric restriction of 30-40% significantly extends lifespan and reduces disease risk in primates, with strong evidence in rodents and preliminary evidence in monkeys. While likely beneficial for humans, strict adherence is difficult, suggesting a need for alternative strategies (mimetics).

Long-term energy-restricted diets for obesity result in modest, heterogeneous weight loss (approx. 3.5-4.5% at 3-4 years) with high rates of weight regain, driven by biological compensatory mechanisms.

Expect modest long-term weight loss (3-5%) rather than dramatic results. Most people will regain some weight due to biological drives (hunger, lower metabolism). Success requires accepting that maintenance is an active, ongoing biological challenge, not just a one-time diet. Focus on strategies to manage hunger and metabolic adaptation rather than expecting permanent loss from the initial diet alone.

Very-low-energy diets (VLED) provide greater short-term weight loss than moderately energy-restricted diets, but do not yield superior long-term weight loss or maintenance.

If you need rapid weight loss for medical reasons, a VLED (<800 kcal/day) works faster than standard diets. However, do not expect it to be easier to maintain long-term. You must pair it with behavioral counseling to prevent rapid weight regain, as the long-term results are no better than standard calorie restriction.

Low-carbohydrate/high-fat diets produce greater short-to-medium term weight loss than low-fat/high-carbohydrate diets, primarily due to spontaneous energy restriction rather than a unique metabolic advantage.

Low-carb diets often lead to faster weight loss in the first 6 months because they help you eat less without counting calories. This is likely due to reduced hunger and food monotony, not a magical metabolic shift. If you prefer this way of eating, it is effective, but you must still manage your total energy intake for long-term success.

Consumption of nuts at recommended doses (approx. 28-42.5g/day) does not cause weight gain or increased adiposity in adults, and is associated with a lower incidence of overweight/obesity in long-term prospective cohorts.

You can eat nuts daily without fear of weight gain. Guidelines recommend about 1-1.5 ounces (28-42.5 grams) per day. They are high in calories but also high in fiber and protein, which helps you feel full. If you replace other snacks with nuts, you may actually lose weight or maintain it better than if you ate low-fat, high-carb snacks.

Ipragliflozin treatment for 24 weeks in type 2 diabetes patients reduces body weight primarily through fat mass loss while preserving total muscle mass and bone mineral content.

If you have type 2 diabetes and are already using insulin, adding 50mg of ipragliflozin daily for 24 weeks can help you lose about 2.8 kg of body weight. This weight loss comes mostly from fat, and your overall muscle mass and bone strength are likely to stay the same, which is important for maintaining strength and health.

Three weeks of 40% caloric restriction in normal-weight young men suppresses leucine flux and oxidation during exercise, yet preserves whole-body aerobic performance despite significant lean mass loss.

If you are a fit young male restricting calories by 40% for three weeks, expect to lose about 2kg of lean mass. However, your ability to perform aerobic exercise (like cycling endurance) will likely remain unchanged because your body adapts by reducing protein breakdown during activity. Do not assume performance will drop just because you are in a deficit.

Caloric restriction in normal-weight men reduces basal metabolic rate (BMR) by approximately 15% over 21 days, independent of the amount of lean mass lost.

When you restrict calories, your resting energy expenditure drops significantly (by ~15% in this study). This drop is not strictly tied to how much muscle you lose, suggesting a general metabolic slowdown to conserve energy.

A 12-week low-calorie diet inducing mild weight loss (approx. 4.8% body weight) significantly increases plasma levels of medium- and long-chain acylcarnitines (e.g., hexanoylcarnitine, octanoylcarnitine) in overweight adults, a change that negatively correlates with reductions in visceral fat area.

For overweight individuals, a sustainable, mild caloric deficit (approx. 300 kcal/day, roughly one-third of a bowl of rice per meal) sustained over 12 weeks is sufficient to reduce visceral fat and increase markers of fatty acid oxidation (acylcarnitines). You do not need extreme restriction to see metabolic benefits; consistency with a modest deficit works.

Negative energy balance induced by aerobic exercise or hypocaloric diet produces similar reductions in visceral adipose tissue (VAT) when weight loss is matched, regardless of exercise amount or intensity.

To reduce visceral fat, focus on creating a consistent negative energy balance. Whether you choose to do this through diet, exercise, or both, the key is the total caloric deficit. You do not need to perform high-intensity or high-volume exercise to see significant visceral fat loss; moderate-intensity aerobic exercise is equally effective. Aim for a modest weight loss (around 7%), which can yield a substantial (~25%) reduction in dangerous visceral fat.

Aerobic exercise reduces liver fat (LF) independently of weight loss, although the magnitude of reduction is modest compared to diet-induced weight loss.

Regular aerobic exercise (150-300 minutes/week) reduces liver fat, even if you don't lose weight. This is a key benefit for metabolic health. While diet-induced weight loss produces larger reductions in liver fat, exercise provides a significant independent benefit. Do not stop exercising if the scale doesn't move; your liver is still benefiting.

High dietary fat intake promotes obesity primarily by increasing energy density and promoting passive overconsumption, while failing to stimulate compensatory fat oxidation, leading to positive energy balance in sedentary individuals.

Focus on reducing the energy density of your diet rather than just cutting fat percentages. High-fat foods are often high-calorie and low-satiety, leading to passive overconsumption. To manage weight, prioritize foods with lower energy density (high water/fiber) and ensure you are not in a caloric surplus, as your body does not efficiently burn off excess dietary fat.

Progressive weight loss triggers adaptive physiological reductions in energy expenditure, specifically a drop in Resting Metabolic Rate (RMR) at ≥5% weight loss and a reduction in Exercise-Induced Energy Expenditure (EIEE) at ≥10% weight loss, which creates metabolic resistance to further weight loss.

If you are losing weight and then stall, do not assume you have failed or are eating too much. Your body is biologically reducing its energy needs (Resting Metabolic Rate drops at 5% loss, Exercise Efficiency increases at 10% loss) to conserve energy. This is a normal survival mechanism. To continue, you must adjust your expectations, potentially increasing physical activity or slightly adjusting intake, knowing this is a temporary physiological hurdle, not a permanent failure.

Low-carbohydrate diets produce significantly greater short-term weight loss (3-8 months) in obese individuals compared to non-carbohydrate-restricted diets, but this advantage disappears in the long term (10-30 months).

If you are obese, a low-carb diet will help you lose more weight than a standard balanced diet for the first 6-8 months. However, do not expect this advantage to last beyond a year; after 10 months, your weight loss will likely match that of someone on a balanced diet. The key benefit of LC diets in the long run is not weight loss, but improved lipid profiles (lower triglycerides, higher HDL).

The 5:2 intermittent energy restriction diet produces weight loss equivalent to standard brief lifestyle advice over 12 months, with no adverse effects on physical activity or macronutrient intake.

Try the 5:2 diet by restricting calories to 500 (women) or 600 (men) on two non-consecutive days a week. Eat normally on the other five days. Expect modest weight loss (around 2kg) over a year, similar to standard diet advice. If you struggle with hunger, know that it often decreases over time, and consider joining a support group to help you stick with it initially.

Performing 250 minutes per week of self-paced aerobic exercise yields modest weight loss regardless of whether the exercise is performed in the morning (06:00–09:00) or evening (16:00–19:00).

If you want to lose weight, focus on getting 250 minutes of moderate aerobic exercise per week. It does not matter if you do it in the morning or the evening; the weight loss results are the same. Choose the time that fits your schedule best to ensure you stick with it.

In healthy, normal-weight young adults, 5:2 intermittent energy restriction (IER) produces equivalent weight loss and postprandial metabolic responses to continuous energy restriction (CER), but yields superior improvements in fasting blood glucose and fasting subjective appetite scores.

If you are a healthy, normal-weight individual looking to lose weight, 5:2 intermittent fasting is just as effective as eating slightly less every day. You will lose the same amount of weight and see similar improvements in how your body handles food after meals. However, 5:2 fasting may offer a slight edge in lowering your fasting blood sugar and reducing hunger feelings when you wake up, which might help with long-term compliance for some people.