Browse the evidence

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.

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.

An 8-week sulfur amino acid restriction (SAAR) diet (~2 g/day) in humans with overweight or obesity produces significantly greater weight loss (~20% greater) compared to a control diet (~5.6 g/day), despite maintaining similar resting metabolic rates.

To lose more weight than standard dietary restriction, try reducing sulfur amino acids (methionine and cysteine) to about 2 grams per day for 8 weeks. This can be done by eating a plant-based diet and avoiding high-sulfur supplements or specific high-sulfur foods, while allowing one flexible meal a week to maintain social life. Expect roughly 20% more weight loss than a standard control diet, even if your resting metabolism doesn't change.

Metabolic adaptation (a lower-than-predicted resting metabolic rate after weight loss) significantly increases the time required to reach specific weight loss goals, independent of dietary adherence.

If you are strictly following a calorie deficit but your weight loss has stalled or slowed significantly, it may be due to metabolic adaptation (a drop in your resting metabolic rate). This is a biological defense mechanism, not a personal failure. Adjusting expectations regarding the timeline, rather than just increasing restriction, is necessary.

Fasting-based strategies (FBS) produce slightly greater short-term weight loss and fat mass reduction compared to continuous caloric restriction (CCR) in obese adults, but these differences are not clinically significant and disappear in long-term interventions (>6 months).

If your goal is weight loss, fasting strategies (like time-restricted eating) might help you lose a bit more weight and fat in the first few months compared to simply counting calories every day. However, this advantage is small (less than 1 kg) and disappears after 6 months. Since both methods result in similar long-term weight loss, choose the approach that fits your lifestyle and is easier for you to maintain consistently.

Intermittent Energy Restriction (IER) produces short-term weight loss comparable to Continuous Energy Restriction (CER), but offers no significant long-term advantages in anthropometric, cardiometabolic, inflammatory, or appetite outcomes.

If you are considering Intermittent Fasting for weight loss, expect it to work similarly to standard daily calorie restriction in the short term. Do not expect it to provide better long-term health or weight maintenance results than simply counting calories every day. The choice between IER and continuous restriction should be based on which pattern you can stick to consistently, as neither offers a long-term advantage over the other.

Static energy balance models (e.g., the 3500 kcal rule) significantly overestimate weight loss because they ignore adaptive thermogenesis, which causes resting energy expenditure to drop beyond what is explained by the loss of metabolically active tissue.

If you are dieting and hitting a plateau despite strict adherence to a calorie deficit, do not simply slash calories further. Your body has likely triggered adaptive thermogenesis, lowering your metabolic rate to protect fat stores. Recognize this as a biological defense mechanism, not a personal failure. Sustainable weight management may require longer adaptation periods or strategies that preserve fat-free mass, rather than aggressive restriction.

Metabolic adaptation (adaptive thermogenesis) is dynamic and largely reversible; it persists during negative energy balance but diminishes or disappears during weight stability or positive energy balance (refeeding).

Once you stop losing weight and reach your goal weight, your metabolic rate may partially recover if you maintain that weight. However, if you regain weight, the metabolic adaptation may return. Long-term maintenance requires accepting that your maintenance calories may be lower than before your weight loss, due to the loss of metabolically active tissue (FFM).

Intermittent Energy Restriction (IER) combined with High-Intensity Interval Training (HIIT) produces greater reductions in body weight, body fat percentage, waist circumference, and hip circumference compared to Continuous Energy Restriction (CER) combined with HIIT in overweight/obese adults, although the difference is not statistically significant in a 4-week trial.

If you are overweight or obese, combining High-Intensity Interval Training (HIIT) with an Intermittent Energy Restriction (IER) diet may help you lose more weight and body fat than a standard daily calorie-restricted diet over a short period. Specifically, eating only 30% of your daily calorie needs on two non-consecutive days a week, while eating normally on the other five days, resulted in nearly double the weight loss (4.6 kg vs 2.5 kg) compared to eating 70% of your needs every day. Although the difference wasn't statistically significant in this small 4-week study, the trend favors IER for body composition improvements.

Weight loss acts as a significant moderator for the effect of combined interventions on visceral fat area (VFA), but not for liver fat or intramuscular triglycerides (IMTG).

Losing weight helps reduce visceral fat, but it may not be enough to reduce liver or muscle fat. If you have concerns about liver or muscle fat, you may need additional strategies beyond just weight loss.

Long-term weight loss via lifestyle interventions reduces cervical subcutaneous adipose tissue (cervical-SAT) significantly, whereas chin subcutaneous adipose tissue (chin-SAT) shows a significant initial reduction but rebounds to baseline levels after 18 months.

If you are losing weight, expect your neck fat to decrease more sustainably than chin fat. While you may see an initial reduction in chin fat, it is likely to return as you maintain your weight long-term, whereas neck fat reduction is more persistent. This does not mean weight loss is ineffective, but rather that fat distribution changes are depot-specific.

Time-restricted eating (TRE) combined with caloric restriction (CR) does not yield superior weight loss compared to caloric restriction alone in overweight and obese women.

If you are already restricting calories to lose weight, adding a strict eating window may not give you any extra weight loss benefit. You can achieve similar results with just calorie control.

A 1-month very-low-calorie ketogenic diet (VLCKD) in women with obesity causes a significant reduction in 24-hour energy expenditure (24hEE) and sleeping metabolic rate (SMR), primarily driven by the loss of lean soft tissue (LST) rather than metabolic adaptation alone.

If you follow a very-low-calorie ketogenic diet, expect your daily calorie burn to drop by about 10% after a month. This isn't just 'metabolic damage'; it's largely because you are lighter and have lost some muscle. To protect your metabolism, prioritize the protein target (1.2-1.5g/kg ideal body weight) and incorporate light resistance or walking to preserve lean tissue.

Intermittent fasting (IF) produces weight loss and metabolic improvements comparable to continuous caloric restriction (CCR) in adults with overweight or obesity, without providing superior benefits.

If you are overweight or obese, intermittent fasting is a viable option for weight loss, but do not expect it to work better than simply eating fewer calories every day. Studies show that IF and continuous calorie restriction lead to similar weight loss (around 5% of body weight) and metabolic improvements over a year. Choose the method that you can stick with long-term, as adherence is key.

Lactobacillus sp. supplementation is safe and well-tolerated in non-comorbid obese individuals, with no significant adverse events reported.

You can take Lactobacillus probiotics with confidence regarding safety. Clinical trials show they are well-tolerated with no significant increase in side effects compared to a placebo.

Increasing exercise volume from 3 sessions/week to 6 sessions/week further reduces fat mass and visceral adipose tissue, although the difference in fat-free mass preservation between 3 and 6 sessions was not statistically significant for absolute fat-free mass kg.

Even 3 days of exercise per week, combined with diet, significantly improves fat loss compared to diet alone. You do not need 6 days to see benefits, but 6 days provides greater fat loss and better muscle preservation.

Higher baseline body weight and BMI strongly predict greater absolute weight loss and fat mass reduction on a very low-calorie ketogenic diet (VLCKD), with men losing significantly more weight than women.

If you have a higher starting weight, you are likely to lose more absolute weight on a VLCKD than someone with a lower starting weight. Men also tend to lose more weight than women on this specific protocol. Use your baseline weight as a predictor of success rather than comparing yourself to others with different starting points.

Flexible time-restricted eating leads to a spontaneous reduction in total energy intake without altering macronutrient composition.

If you use an 8-hour eating window, you will likely eat fewer calories without needing to count them or change your food choices. This spontaneous reduction in energy intake is a key driver of the fat loss seen with flexible TRE.

Exercise frequency positively correlates with gut microbial diversity and the abundance of beneficial bacteria (e.g., Faecalibacterium, Roseburia) that produce short-chain fatty acids (SCFAs), enhancing intestinal barrier function.

Regular physical activity boosts gut bacterial diversity and increases beneficial bacteria that produce SCFAs, which strengthen the gut barrier. Aim for daily exercise to support a healthy microbiome.

Obesity is primarily driven by long-term energy imbalance (calories consumed vs. expended), though food quality and source significantly modulate this relationship.

While energy balance is the fundamental driver of obesity, focusing exclusively on calorie counting may be less effective than prioritizing the quality and source of your food. The paper suggests that what you eat (food sources and nutrient quality) matters more than just how much you eat for controlling weight and preventing disease. Consider shifting your focus from strict calorie restriction to improving the nutritional quality of your diet.