Browse the evidence

Increasing relative exercise intensity shifts fuel utilization from fat to carbohydrate, with carbohydrate becoming the predominant fuel source above the 'crossover point' (typically ~50% VO2max in untrained individuals).

As you exercise harder (higher % of your max capacity), your body switches from burning fat to burning sugar. For fat loss purposes, moderate intensity allows for higher fat oxidation, but high intensity burns more total calories and sugar.

Replacing carbohydrates with Saturated Fat (SFA) has no significant effect on fasting glucose, though it may slightly lower fasting insulin.

If you swap carbohydrates for saturated fats, do not expect your fasting blood glucose to improve. While it may slightly lower fasting insulin, it does not offer the broader metabolic benefits (like improved HbA1c and insulin secretion) that replacing carbs with polyunsaturated fats does.

High-fat, low-carbohydrate diets impair high-intensity endurance performance by down-regulating pyruvate dehydrogenase (PDH) activity and reducing muscle glycogenolysis rates, thereby limiting ATP production at intensities above 60% VO2max.

If you train or race at high intensities (above 60% of your max effort), avoid high-fat, low-carb diets. They slow down your body's ability to use carbohydrates, which are your primary fuel for speed. Stick to high-carbohydrate availability to maintain performance.

Genotype-based personalization of macronutrient intake (high-fat vs. high-carbohydrate) does not result in greater weight loss compared to genotype-discordant diets in individuals with overweight or obesity.

If you are overweight or obese, matching your diet to your genetic profile (e.g., high-fat vs. high-carb) does not provide a weight loss advantage over a diet that doesn't match your profile. Focus on sustainable caloric restriction and macronutrient choices you can maintain, as genetic testing for diet response currently offers no predictive benefit for weight loss magnitude.

Timing protein intake around resistance training sessions provides no additional benefit for muscle strength or hypertrophy compared to consuming the same total daily protein amount at other times.

Stop stressing about eating protein immediately before or after your workout. The research shows that as long as you consume enough protein throughout the day (at least 1.6 g/kg/day is suggested for maximizing muscle accretion), the specific timing of those meals does not significantly impact your muscle growth or strength gains. Focus on hitting your total daily protein goal rather than adhering to a rigid post-workout feeding window.

Trans fat consumption remains high globally, with 99.4% of the adult population consuming levels above the optimal limit of 0.5%E.

Actively minimize trans fat intake. Since 99.4% of the global population exceeds optimal levels, prioritize avoiding processed foods containing partially hydrogenated oils. Aim for <0.5% of energy from trans fats.

Higher circulating and tissue levels of arachidonic acid (AA) are not associated with an increased risk of cardiovascular disease, and may be associated with a lower risk of total CVD.

You do not need to worry about high levels of arachidonic acid (AA) in your blood as a risk factor for heart disease. This study shows that higher AA levels are not associated with increased CVD risk and may even be linked to lower risk.

Obesity can result from an intrinsic metabolic disorder that shifts fuel partitioning toward storage and sequestration in adipose tissue, causing 'internal starvation' and compensatory hyperphagia, independent of excessive energy intake.

This paper argues that for some individuals, obesity is driven by a biological defect in how the body handles fuel (partitioning), not just by eating too much. This biological defect traps energy in fat cells, causing the body to feel starved and triggering hunger. While this explains specific pathological cases in animal models, it suggests that for some humans, treating obesity requires addressing these underlying metabolic shifts rather than just focusing on calorie restriction.

The DASH diet does not significantly affect fasting glucose, Triglycerides (TAG), or HDL cholesterol concentrations.

Do not expect the DASH diet to significantly lower your blood sugar, Triglycerides, or raise your HDL cholesterol. Its primary benefits are on blood pressure and LDL cholesterol. Manage your expectations and focus on the proven benefits.

Short-term dietary interventions cause rapid but transient fluctuations in the adult gut microbiome, which typically returns to its baseline stable state once the intervention ends.

Don't panic if your gut feels different after a few days of eating differently. In adults, the microbiome is resilient and will bounce back to its normal state once you return to your usual diet. To make lasting changes, you need to maintain new dietary habits for months or years, not just days.

Caloric restriction (CR) and dietary restriction (DR) extend lifespan and healthspan, largely by suppressing the IIS/mTOR axis, although CR may also act through mTOR-independent mechanisms.

Reducing calorie intake by 20-40% or restricting specific nutrients like protein or methionine can extend lifespan and healthspan in model organisms. This works partly by suppressing the mTOR pathway, but also through other mechanisms. For humans, this suggests that mindful eating, potentially focusing on protein quality and quantity, may offer longevity benefits.

Low-carbohydrate diets are not superior to higher-carbohydrate or low-fat diets for weight loss in adults with type 2 diabetes.

Do not expect low-carb diets to produce more weight loss than low-fat or high-carb diets if calories are matched. The choice of macronutrients should be based on preference and adherence, not expected superior weight loss results.

A long-term dietary intervention reducing total fat to 20% of calories and increasing fruits, vegetables, and grains does not significantly reduce the risk of coronary heart disease, stroke, or composite cardiovascular disease in postmenopausal women.

For postmenopausal women, simply switching to a low-fat diet (20% of calories) with more fruits, vegetables, and grains is not enough to prevent heart disease or stroke on its own. While it may slightly improve cholesterol and blood pressure, it does not significantly lower cardiovascular event rates. More targeted interventions focusing on specific risk factors are likely necessary.

In normal, non-overfed humans, de novo hepatic lipogenesis (the conversion of carbohydrate to fat) is a quantitatively minor pathway, contributing less than 2% of circulating VLDL fatty acids even under high carbohydrate refeeding conditions.

You do not need to fear carbohydrates turning into body fat. In healthy individuals, even with high carbohydrate intake, the body converts less than 2% of those carbs into fat. Focus on total calorie balance and overall diet quality rather than avoiding carbs to prevent fat gain.

Atherogenesis is fundamentally driven by the accumulation of oxidatively modified LDL in the arterial intima, facilitated by endothelial dysfunction and scavenger receptor uptake by macrophages to form foam cells.

High LDL cholesterol is a primary cause of atherosclerosis. The risk is highest when LDL is oxidized and taken up by macrophages to form foam cells. Managing LDL levels and reducing oxidative stress are key to preventing plaque buildup.

Athletes should consume 1.4–2.0 g of protein per kg of body weight per day to optimize lean body mass and strength during resistance training.

If you train with weights, aim for 1.4 to 2.0 grams of protein for every kilogram of your body weight each day. This range is the scientific standard for building and keeping muscle while you train hard.

Natural bodybuilders in contest preparation should consume 2.3-3.1 g/kg of lean body mass per day of protein to maximize lean body mass retention.

Calculate your lean body mass (LBM) and multiply it by 2.3 to 3.1 to determine your daily protein target in grams. For example, if your LBM is 150 lbs (approx 68 kg), aim for 156-211 grams of protein per day. This high intake is crucial to prevent muscle loss while you are dieting. If you are leaner or have a larger caloric deficit, aim for the higher end of this range.

In overweight/obese adults, a low-carbohydrate diet (26% of calories) without calorie restriction produces significantly greater weight loss and BMI reduction than a calorie-restricted diet (1200-1500 kcal) with standard carbohydrate intake (55-65%).

If you are overweight or obese, try reducing your carbohydrate intake to about 26% of your total calories (roughly 50-60g of carbs per day for many adults) without worrying about counting calories. Eat more fat and protein. You do not need to restrict your total energy intake to lose weight effectively; in fact, you may eat more calories than on a standard low-calorie diet and still lose more weight. This approach was shown to be superior to standard calorie restriction over 12 weeks.

For individuals performing resistance training, muscle strength increases linearly with total protein intake up to 1.5 g/kg body weight per day, with no additional benefit from higher intakes.

If you lift weights, aim for 1.5 grams of protein per kilogram of body weight daily. This is the sweet spot for maximizing strength gains. Eating more than this does not provide additional strength benefits.

In overweight and obese adults, low-carbohydrate diets (LCD) produce greater reductions in triglycerides, diastolic blood pressure, and body weight, along with greater increases in HDL cholesterol, compared to low-fat diets (LFD) over a duration of 6 to 23 months.

If you are overweight or obese, switching to a diet with less than 40% of your calories from carbohydrates (instead of less than 30% from fat) is likely to help you lose more weight, lower your triglycerides, raise your 'good' HDL cholesterol, and lower your diastolic blood pressure over the next 6-23 months. However, this benefit disappears after 24 months, where both diets are equally effective.

Limiting consumption of sugar-sweetened beverages (SSBs) is a critical intervention for weight control and obesity prevention.

Cut out sugary sodas and sweetened juices. Replacing them with water or non-caloric beverages is one of the most effective single changes for preventing weight gain, especially in children.

Adherence to a traditional Mediterranean dietary pattern is associated with reduced overall mortality and lower incidence of cardiovascular disease, coronary heart disease, and stroke.

Adopt a dietary pattern rich in vegetables, fruits, nuts, legumes, and whole grains, using olive oil (or local healthy oils like mustard/rice bran oil) as the primary fat source. Limit red meat and processed foods. If you drink alcohol, do so moderately with meals, preferably wine, though this may not apply to all populations. Focus on the overall pattern rather than single nutrients.

The health benefits of the Mediterranean diet are driven by specific components, particularly high plant food consumption, moderate alcohol (wine), low meat intake, and olive oil, rather than a single 'magic bullet' nutrient.

Focus on increasing your intake of vegetables, fruits, nuts, and legumes, as these contribute the most to health benefits. Complement this by reducing red meat and using olive oil (or similar healthy oils) as your primary fat source. If you drink alcohol, do so moderately with meals.

Adherence to the Alternate Healthy Eating Index (AHEI), which emphasizes unsaturated fats, whole grains, and moderate alcohol while limiting red/processed meats and trans fats, significantly reduces the risk of major chronic disease and cardiovascular disease in adults compared to low adherence.

To lower your risk of heart disease and chronic illness, focus on the quality of your food choices rather than just calories. Prioritize vegetables, fruits, whole grains, fish, and poultry over red and processed meats. Use unsaturated oils (like olive or canola oil) instead of butter or animal fats. If you drink alcohol, limit it to moderate levels (1-2 drinks for men, 1 for women). This pattern, known as the Alternate Healthy Eating Index, has been shown to significantly reduce cardiovascular risk in large population studies.