Browse the evidence

A weight loss diet reduced in carbohydrates and high in protein decreases the abundance of Eubacterium rectale and Collinsella aerofaciens, likely due to reduced substrate availability for these specific bacterial groups.

When following a low-carbohydrate weight loss diet, you may see a decrease in certain butyrate-producing bacteria like E. rectale. This is likely due to less carbohydrate substrate for them to ferment. This is a normal physiological response to the diet composition rather than a sign of gut damage.

Sleep serves to enforce rest and fasting, thereby optimizing metabolic processes (anabolism vs catabolism) at the appropriate phase of the 24-hour cycle.

Align your eating schedule with your active hours. Avoid large meals during your habitual sleep window to allow your body to perform restorative catabolic processes (like gluconeogenesis) without interference from incoming nutrients.

Reduced muscle mass is a critical phenotypic criterion for malnutrition, measurable via body composition techniques (DXA, BIA, CT) or anthropometrics (calf/arm circumference) when advanced tools are unavailable.

Check muscle mass, not just weight. Use simple measurements like calf or arm circumference if you don't have advanced body composition tools. Low muscle mass is a key sign of malnutrition.

Higher adherence to a Mediterranean diet, as measured by a 14-item screener, is inversely associated with abdominal obesity (waist-to-height ratio) and general obesity in high-risk adults, independent of total caloric intake.

To reduce abdominal fat, prioritize a Mediterranean dietary pattern over simple calorie restriction. Focus on increasing intake of nuts, olive oil, vegetables, and fish, while reducing sweetened beverages and red/processed meats. Use the waist-to-height ratio as a more accurate health indicator than BMI alone. This approach is particularly effective for individuals with existing cardiovascular risk factors.

Ultra-processed foods act as significant vectors for 'risk ingredients' (added sugars, sodium, trans-fats, and cosmetic additives), contributing disproportionately to the intake of these harmful components compared to unprocessed foods.

Check labels for added sugars, sodium, and trans-fats. UPFs often contain high levels of these 'risk ingredients' even if they appear healthy (e.g., flavored yogurts, sauces). Reducing UPF intake naturally reduces the intake of these harmful components.

Among women who achieved the lowest intakes of saturated fat (<6.1% energy) or trans fat (<1.1% energy), or highest intakes of vegetables and fruits (>=6.5 servings/day), there was a trend toward reduced CHD risk, although it did not reach statistical significance after adjustment for confounders.

While the overall low-fat diet didn't prevent heart disease, focusing specifically on minimizing saturated and trans fats, and maximizing vegetable and fruit intake, may offer some protective benefit against coronary heart disease.

Replacing saturated fats with monounsaturated or polyunsaturated fats reduces LDL cholesterol without lowering HDL, thereby reducing coronary heart disease risk, whereas replacing saturated fats with carbohydrates may lower HDL and reduce the predicted benefit.

To improve your heart health, focus on swapping saturated fats (like butter and fatty meats) for unsaturated fats (like olive oil, nuts, and fish). Avoid simply replacing fat with refined carbohydrates, as this can lower your good cholesterol (HDL) and reduce the heart benefits.

Adopting a vegetarian or vegan diet is associated with a significantly reduced risk of ischemic heart disease incidence and mortality compared to an omnivorous diet.

If you switch to a vegetarian or vegan diet, you may lower your risk of heart disease by about 25% compared to eating meat. This is based on large observational studies. Ensure your diet is balanced to maintain health.

High intake of saturated fat and cholesterol is associated with an increased risk of incident dementia, particularly dementia with a vascular component.

If you are over 55, consider reducing your intake of saturated fats and cholesterol to potentially lower your risk of dementia. Focus on balancing your diet with healthier fats, such as those found in fish, which this study links to a reduced risk.

Fish consumption, a source of n-3 polyunsaturated fatty acids, is associated with a reduced risk of incident dementia, particularly Alzheimer's disease.

Include fish in your diet regularly to potentially lower your risk of dementia, especially Alzheimer's disease. Even modest consumption levels were associated with significant benefits in this study.

Dietary fats modulate postprandial inflammation and metabolic risk, with long-chain n-3 polyunsaturated fatty acids (LC n-3 PUFA) attenuating adipose inflammation and restoring endogenous anti-inflammatory lipid mediators (resolvins/protectins) in obese individuals, whereas saturated fatty acids (SFA) may promote pro-inflammatory states via inflammasome activation.

Focus on the quality of your dietary fats rather than just reducing total fat. Incorporate sources of long-chain n-3 polyunsaturated fatty acids (like fatty fish) to help reduce inflammation and improve metabolic health, especially if you have excess body weight. Be mindful that high intake of saturated fats may promote inflammatory pathways, but the impact can vary based on individual genetics and overall diet context.

A dietary intervention reducing fat intake to approximately 15-20% of calories significantly improves relapse-free survival in women with early-stage breast cancer, with a greater benefit observed in those with estrogen receptor-negative (ER-negative) tumors.

For breast cancer survivors, adopting a low-fat diet (targeting ~15-20% of calories from fat) is a feasible lifestyle change that may improve survival outcomes, particularly for those with ER-negative tumors. This should be done under the guidance of a dietitian to ensure nutritional adequacy, focusing on fat gram counting and self-monitoring without necessarily aiming for weight loss.

High carbohydrate intake is positively associated with the abundance of the archaeal genus Methanobrevibacter and the fungal genus Candida in the human gut microbiome, whereas high protein, amino acid, and fatty acid intake is negatively associated with these taxa.

If you eat a diet high in carbohydrates, you are likely to have higher levels of Methanobrevibacter (an archaea) and Candida (a fungus) in your gut. Conversely, diets high in protein, amino acids, and fats are associated with lower levels of these specific taxa. This relationship holds for both long-term dietary habits and recent food intake, particularly for Candida.

Asian and Hispanic populations have a higher risk of type 2 diabetes and hypertension at lower BMIs compared to Caucasians.

If you are Asian or Hispanic, your risk for diabetes and heart disease starts at a lower weight than the standard 'obese' BMI. Aim for a lower BMI (around 21-23) and monitor waist circumference, not just the scale.

Consumption of sugar-sweetened beverages containing fructose or high fructose corn syrup promotes de novo lipogenesis and triggers inflammatory responses leading to hepatocyte apoptosis, directly contributing to the development of nonalcoholic fatty liver disease (NAFLD).

Limit sugar-sweetened beverages, particularly those with high fructose corn syrup or sucrose. The paper links drinking two average servings daily for six months to the development of NAFLD features. Reducing these beverages is a primary dietary intervention to lower liver fat accumulation.

Moderate carbohydrate intake (50–55% of energy) is associated with the lowest all-cause mortality risk, whereas both low (<40%) and high (>70%) carbohydrate intakes are associated with increased mortality.

Aim for 50–55% of your daily calories from carbohydrates. This range is associated with the lowest risk of death in large long-term studies. Avoid going below 40% or above 70% of calories from carbs, as both extremes are linked to higher mortality.

When carbohydrates are restricted, replacing them with animal-derived protein and fat increases mortality risk, whereas replacing them with plant-derived protein and fat decreases mortality risk.

If you choose to eat fewer carbohydrates, replace them with plant-based proteins and fats (like nuts, vegetables, and whole grains) rather than animal products (like red meat and dairy). This substitution is associated with a lower risk of death.

Substituting 3% of total energy intake from plant protein for animal protein (specifically processed or unprocessed red meat) is associated with significantly lower all-cause and cardiovascular mortality.

To lower your risk of dying from heart disease or other causes, swap 3% of your daily calories from animal protein (especially processed and unprocessed red meat) with plant protein (beans, nuts, legumes). This swap is most beneficial if you have other unhealthy lifestyle habits like smoking, being overweight, or being inactive. You do not need to change your total protein amount, just the source.

High intake of animal protein is associated with higher cardiovascular mortality, while high intake of plant protein is associated with lower all-cause and cardiovascular mortality, particularly in individuals with unhealthy lifestyle factors.

If you smoke, drink heavily, are overweight, or are inactive, the source of your protein matters more for your heart health. High animal protein intake increases your risk of dying from heart disease, while high plant protein intake lowers your risk of dying from any cause. Focus on getting protein from plants, especially if you have other health risks.

Western diets should reduce the n-6 to n-3 fatty acid ratio from the current 10-25:1 to approximately 1-2:1 to support cardiovascular health, normal development, and homeostasis.

Shift your fat sources. Reduce intake of corn, soybean, and sunflower oils (high in n-6) and increase sources of alpha-linolenic acid (ALA) like flaxseed, canola, and walnuts, while incorporating marine sources of EPA/DHA. Aim for a dietary ratio of n-6 to n-3 closer to 4:1 or lower, rather than the typical 15:1 found in Western diets.

Increasing dietary alpha-linolenic acid (ALA) reduces platelet aggregation and improves cardiovascular risk markers, although it is less potent than long-chain n-3 fatty acids (EPA/DHA) due to conversion competition with linoleic acid (LA).

If you rely on plant sources like flax or walnuts, minimize high-n-6 oils (corn, soy, sunflower) in your diet. This reduces competition for enzymes, allowing your body to convert more ALA into beneficial EPA/DHA. Note that ALA alone will not lower triglycerides as effectively as fish oil.

US adults significantly improved overall diet quality between 1999 and 2012, driven primarily by increased consumption of whole grains, nuts/seeds, and whole fruit, alongside decreased consumption of sugar-sweetened beverages.

Focus on swapping sugar-sweetened beverages for water or unsweetened options, and increasing intake of whole grains, nuts, seeds, and whole fruit. These specific changes are the primary drivers of improved diet quality in the US population.

Visceral adipose tissue accumulation drives insulin resistance and metabolic syndrome, whereas subcutaneous adipose tissue accumulation is protective or neutral.

Focus on reducing visceral fat (belly fat) rather than just total weight. While subcutaneous fat (hips/flanks) is less harmful, visceral fat is a primary driver of insulin resistance. Strategies that target visceral fat, such as aerobic exercise and stress management, are likely more effective for metabolic health than weight loss alone.

Obese individuals exhibit a specific, differential pattern of dietary underreporting where total energy intake is underreported significantly more than protein intake, leading to an overestimation of the proportion of energy derived from protein.

If you are obese, your self-reported diet likely underestimates your total calorie intake more than your protein intake. This means your calculated 'protein percentage' of total calories is likely artificially high. To get an accurate picture of your macronutrient balance, rely on biomarkers or objective measures rather than just your memory of what you ate, as you likely omit high-carb/fat snacks while remembering protein sources.