Browse the evidence

Sex is a significant predictor of the disparity (range) between highest and lowest daily carbohydrate intakes during peak week, with males exhibiting a wider range than females.

If you are male, expect to cycle your carbohydrates more aggressively (higher highs and lower lows) during peak week than if you are female. The study found sex was the only significant factor predicting this disparity.

A bodybuilding-specific carbohydrate-loading protocol (following glycogen depletion) increases muscle thickness and body mass, but these changes are likely too small to exceed measurement error or daily biological fluctuations to be considered practically meaningful for aesthetics.

If you are an experienced bodybuilder, you can try a carbohydrate loading protocol (approx 9g/kg CHO on the final day after depletion) to potentially increase muscle thickness. However, do not expect guaranteed visual improvements, as the changes are small and may not be visible to judges. If you are a newer competitor, avoid this protocol due to the risk of negative effects (like obscuring definition) with little aesthetic reward. Always test your specific response to loading during training, not just before the show.

Saturated fat intake (8% of energy) is not associated with increased mortality or cardiovascular disease risk compared to higher fat intakes.

Do not fear saturated fat from whole food sources. The PURE study suggests that moderate saturated fat intake (around 8-10% of energy) is not associated with increased health risks. Focus on the overall quality of your diet, including the source of fats and carbohydrates.

Plasma fatty acid levels (specifically C16:0, C20:3 n-6, and C20:5 n-3) are independently associated with obesity risk in ethnic minority populations, whereas dietary fatty acid intake is not a consistent independent predictor.

For individuals in these ethnic groups, monitoring blood lipid profiles (specifically saturated and certain polyunsaturated fatty acids) may be more relevant for assessing obesity risk than tracking dietary fat intake alone. Specific fatty acids like C16:0, C20:3 n-6, and C20:5 n-3 were linked to higher obesity odds.

The correlation between dietary fatty acid intake and plasma fatty acid levels varies significantly by ethnicity, being positive in some groups (Bulang, Naxi) but absent in others (Hani, Wa).

Nutritional interventions targeting fatty acid intake may need to be tailored to specific ethnic backgrounds, as the link between what you eat and your blood fat levels is not universal.

Orlistat is the least effective registered anti-obesity drug for weight reduction and is associated with significant gastrointestinal side effects.

Orlistat (120 mg three times daily) is available but is considered the least effective registered option for weight loss and is associated with significant gastrointestinal side effects. It is typically used as a third-line treatment.

Restricting saturated fat intake does not consistently reduce cardiovascular disease risk and may be associated with lower mortality when replaced by carbohydrates, challenging blanket low-fat dietary guidelines.

Stop fearing saturated fat in whole foods like meat, dairy, and nuts. Current evidence suggests that restricting these foods does not lower heart disease risk and may be worse if you replace them with high-carbohydrate foods. Focus on eating whole, unprocessed foods rather than isolating fat content.

Self-reported macronutrient intake (fat, carbs, protein, sugar) is not consistently associated with future hypothalamic gliosis in humans.

Unlike in animal studies, simply changing your macronutrient ratios (fat, carbs, protein) doesn't seem to predict brain inflammation in humans. Focus on overall metabolic health rather than obsessing over specific macronutrient percentages for brain health.

High dietary linoleic acid intake inhibits the conversion of short-chain omega-3 fatty acids (ALA) to long-chain omega-3 fatty acids (EPA/DHA) by inhibiting delta-desaturase enzyme activity.

If you consume high amounts of seed oils, your body's ability to convert plant-based omega-3s (ALA) into active forms (EPA/DHA) is reduced. Consider direct sources of EPA/DHA if you are not consuming fish.

Genotype-matched dietary interventions (low-fat vs. low-carbohydrate) may not consistently predict weight loss success in postmenopausal women compared to general overweight populations.

Do not rely solely on genetic testing to dictate whether you should eat low-fat or low-carb. Focus on sustainable dietary patterns like DASH or MED, as genotype matching has not consistently proven superior for weight loss in recent large studies.

Protein supplementation provides no additional performance benefit over resistance training alone for resistance-trained athletes who consume adequate dietary protein.

If you are already eating enough protein from food to support your training, adding protein supplements will not make you stronger or bigger than training alone. Focus on your resistance training program and a balanced diet. If you struggle to meet protein needs through food, supplements can help, but they are not a magic performance booster.

Other protein supplements (soy, casein, pea, rice, etc.) do not show statistically significant differences in muscle strength or fat-free mass gains compared to placebo in healthy adults undergoing resistance training.

If you are using other protein supplements like soy, casein, or pea protein, they may not provide significant additional benefits for muscle strength or mass gains compared to a placebo. Focus on collagen or whey if you want to maximize your results.

GLP-1 receptor agonist pharmacotherapy in older adults causes significant loss of lean skeletal muscle mass (approx. 26-40% of total weight lost), which independently predicts adverse outcomes including mortality, functional decline, and frailty.

If you are an older adult using GLP-1 medications, do not focus solely on the number on the scale. The medication causes you to lose muscle along with fat, which can lead to frailty and higher mortality. You must actively counteract this by combining your medication with resistance exercise and adequate protein intake to preserve your muscle mass.

Rapid and significant weight loss induced by Tirzepatide leads to aesthetic changes, including facial volume loss ('Ozempic face'), skin laxity, and altered collagen structure, which are secondary to fat loss rather than direct drug toxicity.

Significant weight loss can cause your face to look older or saggy due to loss of facial fat. This is a side effect of the weight loss, not the drug itself. Eating enough protein and vitamins (like D and B12) during treatment may help maintain skin health.

In Korean adults, adherence to a low-carbohydrate diet (LCD) is associated with higher odds of metabolic syndrome, primarily because LCDs in this population often substitute refined carbohydrates with processed meats and animal fats rather than healthy unsaturated fats.

If you are Korean or have an East Asian metabolic profile, simply reducing carbohydrates may not lower your metabolic syndrome risk and could potentially increase it if you replace rice with processed meats or unhealthy fats. Focus on the quality of your diet—choosing whole grains, unsaturated fats, and lean proteins—rather than just cutting carbs.

There is no significant difference between various macronutrient dietary groups (VLCLP, MCLP, MCHP, etc.) in their ability to lower blood glucose, blood pressure, or total cholesterol compared to a moderate fat-low protein (MFLP) control diet.

Do not expect that switching to a specific macronutrient ratio (like Keto or Low Fat) will significantly lower your blood pressure, blood glucose, or total cholesterol compared to a standard moderate-fat diet. The evidence for these specific outcomes is weak and shows no clear winner among the diets studied.

Personalized nutrition significantly reduces carbohydrate intake compared to control diets, with a median mean difference of -10.8% of energy.

Personalized nutrition interventions in this review led to a significant reduction in carbohydrate intake (averaging 10.8% less energy from carbs) compared to standard diets. This suggests that personalized approaches may naturally guide patients toward lower-carb profiles that benefit their specific metabolic health.

Post-exercise consumption of soy flour (providing ~29g protein) combined with structured resistance training significantly increases leg muscle strength in young athletes.

If you are a young athlete doing leg resistance training (like lunges) twice a week, consuming about 73 grams of soy flour mixed with water and a bit of sugar immediately after your workout can help increase your leg strength. This works best when your training is structured and progressive.

Natural compounds, specifically oligomeric procyanidins from apple polyphenol extract and tetrahydrofuran from nutmeg, inhibit pancreatic lipase activity in vitro and in animal models, potentially offering safer alternatives to synthetic inhibitors.

Some natural extracts, like those from apples (procyanidins) and nutmeg, show promise in blocking fat-digesting enzymes in lab tests. However, they are not yet proven to be effective or safe for weight loss in humans compared to established treatments. Do not rely on them as a primary weight loss strategy without medical guidance.

Low-carbohydrate diet scores are not associated with a reduced risk of type 2 diabetes.

Following a low-carbohydrate diet does not appear to offer a specific advantage in reducing the risk of type 2 diabetes compared to moderate-carbohydrate diets, according to this meta-analysis. Focus on overall dietary quality and maintaining a healthy weight.

Timing of protein ingestion (before vs. after resistance training) does not significantly affect total body lean mass gains.

You do not need to rush to drink protein immediately after your workout. As long as you consume your protein within a few hours before or after training, your muscle growth will be the same. Focus on getting enough total protein throughout the day rather than stressing about the exact timing.

Timing of protein ingestion does not significantly affect upper body (chest press) strength gains.

For upper body exercises like chest press, it does not matter if you drink your protein before or after your workout. Your strength gains will be the same. Focus on getting enough total protein throughout the day.

The 'Lipid Theory' and 'Food Pyramid' guidelines, which recommend limiting saturated fat and increasing carbohydrates, have contributed to the 'diabesity pandemic'.

Be critical of official dietary guidelines. The paper argues that the 'Lipid Theory' and 'Food Pyramid' have contributed to the 'diabesity pandemic'. Focus on whole food sources of carbohydrates and healthy fats, and avoid processed foods and refined sugars.

The German Nutrition Society's (DGE) 2024 dietary guidelines, which prioritize minimizing environmental burden and deviation from current consumption over health outcomes, are methodologically flawed and potentially harmful because they significantly increase carbohydrate intake while reducing protein and fat without evidence-based justification.

Do not follow the new DGE guidelines blindly, especially if you are concerned about metabolic health, weight, or blood sugar. The guidelines significantly increase carbohydrates and decrease fats and proteins without strong evidence. Instead, focus on nutrient-dense foods, prioritize protein and healthy fats for satiety and metabolic health, and consider that local, sustainably sourced animal products can be part of a healthy and environmentally sound diet.