Browse the evidence

Increasing daily protein intake to 1.4 g/kg body weight, specifically emphasizing lean beef, does not enhance resistance training-induced adaptations in skeletal muscle volume, strength, or patellar tendon cross-sectional area in older women compared to a normal protein intake of 0.8 g/kg.

If you are an older woman doing resistance training, you do not need to force-feed yourself high amounts of protein or lean beef to see muscle and strength gains. A standard intake of 0.8 g of protein per kg of body weight is sufficient to support these adaptations. While higher protein (1.4 g/kg) from beef did not hurt, it also did not help more than the lower amount. Focus on consistent training rather than maximizing protein intake beyond standard recommendations.

Increasing protein intake from 1.0 g/kg/day to 1.6 g/kg/day via egg white or whey protein supplementation does not further enhance physical performance (strength, endurance, aerobic capacity) in recreationally trained males and females undergoing high-intensity functional training (HIFT).

If you are already eating about 1 gram of protein per kilogram of body weight daily, adding extra protein supplements (like whey or egg white) will not make you stronger or more enduring during high-intensity functional training. Focus on your training consistency and total daily protein intake rather than buying extra supplements.

In healthy adults, dietary glycemic index (GI) and glycemic load (GL) are not significantly associated with metabolic syndrome after adjusting for confounders such as BMI, physical activity, and macronutrient intake.

For healthy adults, simply avoiding high-GI foods may not prevent metabolic syndrome if your overall diet is high in saturated fats or sugars. Focus on maintaining a healthy weight, staying active, and balancing your macronutrients rather than obsessing over glycemic index numbers.

In healthy adults, there is no significant association between dietary glycemic load (GL) and metabolic syndrome or its components.

Tracking the total glycemic load of your diet may not be necessary for preventing metabolic syndrome in healthy individuals. Focus on overall diet quality, including fiber and healthy fats, rather than just the total glycemic impact of carbohydrates.

High carbohydrate intake (highest tertile, median 59.3% energy) is associated with increased MRI-detected vascular brain injury (covert brain infarcts and white matter hyperintensities) and lower cognitive scores (MoCA and DSST) in middle-aged adults.

If you are middle-aged and concerned about brain health, look at your overall macronutrient balance. High carbohydrate intake (over 59% of calories) is linked to more silent brain injuries and lower cognitive scores. Try shifting some of those carbohydrates to healthy fats, like those found in nuts, olive oil, or fish, which were associated with better brain health in this study.

Gluten-free diets do not appear to impact IBD disease activity, hospitalization, or surgery rates, despite many patients self-reporting symptom improvement.

For most IBD patients, a gluten-free diet does not reduce disease activity, hospitalizations, or surgery rates. While some patients report subjective symptom improvement, this does not translate to better clinical outcomes. It is not recommended as a primary treatment for IBD unless Celiac Disease is diagnosed.

Higher total protein intake (up to ~116g/day) is not significantly associated with reduced risk of cardiovascular disease (CVD), coronary heart disease (CHD), or stroke in middle-aged adults.

If you are a middle-aged adult concerned about heart disease, simply eating more protein than you currently do is unlikely to lower your risk of heart attack or stroke. Focus on overall dietary patterns and established risk factors rather than just maximizing protein grams.

Higher diversity of protein sources (specifically 'count' of sources) is weakly associated with a marginally higher risk of CVD, while 'dissimilarity' of sources shows no association.

Don't assume that eating many different types of protein (e.g., chicken, beef, fish, beans, tofu) will protect your heart. This study suggests that having a high count of protein sources might be weakly linked to higher risk, possibly due to what those sources are (e.g., processed meats).

Modern commercial Paleolithic diet variants (low-carb/high-fat) and extreme Carnivore diets contradict anthropological evidence of ancestral carbohydrate intake (35-72% of energy) and may increase cardiovascular risk by promoting high saturated fat intake and dyslipidemia.

If you are following a commercial Paleo or Carnivore diet, be aware that your macronutrient profile (very low carb, high saturated fat) differs significantly from what anthropological evidence suggests ancestral humans ate. Current scientific consensus links high saturated fat intake to elevated LDL and cardiovascular risk. While these diets may offer short-term benefits (possibly via elimination of processed foods or FODMAPs), long-term adherence to high saturated fat levels may increase cardiovascular risk. Consider aligning your diet with evidence-based guidelines that limit saturated fat, rather than relying on evolutionary arguments alone.

A diet high in fiber and low in glycemic index does not enhance weight loss or fat loss compared to a standard diet when both are in a caloric deficit.

Eating a low-glycemic, high-fiber diet won't help you lose more weight than a standard diet if you are already eating fewer calories. Focus on the total calorie deficit rather than strictly avoiding high-glycemic foods.

Time-restricted eating (TRE) does not significantly preserve lean body mass compared to control groups in adults with obesity.

Don't worry that TRE will cause you to lose muscle faster than a standard diet. The evidence shows lean mass loss is similar to control groups. Focus on protein intake and strength training to preserve muscle, as TRE itself doesn't offer a specific advantage in this regard.

Long-term adherence to a low-carbohydrate (LC) diet (defined as <45% energy from carbs) results in significant weight regain and increased triglyceride levels compared to a low-fat (LF) diet in overweight or obese adults.

If you are trying to lose weight long-term, a strict low-carb diet (<45% carbs) may not be better than a low-fat diet and could actually lead to more weight regain and higher triglycerides after a year. Focus on sustainable calorie restriction and food quality rather than extreme macronutrient restriction. Low-fat diets showed better or equivalent long-term weight maintenance and lipid profiles in this review.

Global consumption of vegetable oils has increased significantly (threefold in developing countries), contributing to higher energy availability and improved food security, but also altering macronutrient profiles.

Vegetable oil consumption has tripled in many developing nations, boosting calorie availability. While this helps food security, it also changes the diet's fat profile. Monitor total fat intake even when using plant-based oils.

Meat consumption, particularly poultry, has increased dramatically in developing countries (e.g., China, Brazil), while red meat consumption has stagnated or declined in industrial nations.

In developing economies, meat consumption is rising fast, especially poultry. In industrial nations, red meat intake is falling, possibly due to health scares and changing preferences. Prioritize poultry if increasing animal protein intake.

High-fat diets and saturated fatty acids can disrupt intestinal barrier integrity and promote systemic inflammation via TLR4 activation and bile acid alterations.

Limiting saturated fat intake and focusing on unsaturated fats can help maintain gut barrier integrity and reduce systemic inflammation, especially in individuals prone to metabolic issues.

The method of calculating 'available carbohydrate' significantly impacts GI values, with newer methods accurately measuring resistant starch (RS) preventing the overestimation of GI in foods with indigestible fibers.

Be aware that older GI values might be slightly inaccurate for foods high in resistant starch (like cooled potatoes or legumes). Newer testing methods provide more accurate GI scores by accounting for indigestible fibers.

Reducing dietary carbohydrate intake to low levels (24 g/day) in obese individuals significantly decreases fecal butyrate concentrations and reduces the abundance of butyrate-producing bacteria (specifically Roseburia spp. and Eubacterium rectale).

If you follow a very low-carbohydrate diet (like Keto), you may see a significant drop in butyrate, a beneficial compound for colon health. This happens because you are feeding fewer of the bacteria that produce it. To mitigate this, consider including specific fermentable fibers or resistant starches even on a low-carb diet to support these bacteria.

During prolonged low-intensity exercise, the relative contribution of free fatty acids (FFA) to total oxygen metabolism in working muscles increases progressively, eventually exceeding the contribution of glucose.

For long, slow workouts, your body naturally shifts to burning more fat as time goes on. You don't need to force-feed yourself carbohydrates during these sessions; your body will access stored fat efficiently.

Liver PPAR-gamma is essential for triglyceride clearance; its absence causes hyperlipidemia and insulin resistance even when hepatic steatosis is reduced.

Do not assume that reducing liver fat automatically improves metabolic health. The liver plays a critical role in clearing triglycerides from the blood. If the mechanism for this clearance (PPAR-gamma) is impaired, reducing liver fat can actually worsen insulin resistance and heart disease risk by forcing lipids into other tissues like muscle and fat.

Liver PPAR-gamma protects extra-hepatic tissues from triglyceride accumulation and insulin resistance by facilitating hepatic lipid clearance.

Your liver's ability to clear fats from your blood is critical for your muscle health. If your liver cannot process lipids efficiently (due to low PPAR-gamma activity), those fats accumulate in your muscles, leading to insulin resistance and metabolic disease, even if your liver itself looks healthy.

Urbanization is a primary driver of dietary changes, specifically increasing energy intake from fats and sweeteners, independent of total GNP per capita.

Moving to a city in a low-income country tends to increase fat and sugar intake. Policies should focus on urban food environments to prevent this shift.

Inhibition of Acetyl-CoA Carboxylase 1 (ACC1) reduces de novo fatty acid synthesis and hepatic triglyceride accumulation, but may not sufficiently improve insulin sensitivity or fatty acid oxidation on its own compared to ACC2 inhibition.

Blocking the creation of new fat (via ACC1) reduces liver fat but does not fix insulin resistance or obesity on its own. The body compensates by trying to store fat elsewhere or failing to burn it. Effective treatment requires targeting ACC2 to ensure fat is actually burned, not just not made.

Lactate inhibits lipolysis in adipose tissue via HCAR-1 receptor binding and inhibits mitochondrial fatty acid oxidation via malonyl-CoA, thereby controlling energy substrate partitioning.

During high-intensity exercise, your body temporarily shifts away from burning fat to use lactate as fuel. This is a normal metabolic switch, not a failure of fat loss mechanisms.

The introduction of supermarkets into deprived communities has mixed effects on fruit and vegetable intake; while some studies show small improvements, robust quasi-experimental studies (e.g., in Glasgow) found little to no effect compared to control areas.

Moving to a neighborhood with a supermarket or expecting a new store to open near you is unlikely to significantly change your diet or help you lose weight. Studies show that simply adding stores does not reliably increase fruit and vegetable intake. Focus on your actual purchasing habits, budget, and food choices rather than relying on the presence of a specific store type.