Browse the evidence

Low-carbohydrate diets (defined as <40% energy) improve short-term cardiovascular risk markers, specifically reducing triglycerides and increasing HDL, compared to low-fat diets, but these benefits diminish or become insignificant after 24 months.

If you switch to a low-carb diet (under 40% of calories), you will likely see improved cholesterol markers (lower triglycerides, higher HDL) and weight loss within the first 6 months. However, these specific lipid benefits tend to fade after 2 years, and LDL cholesterol might rise slightly. Because long-term adherence is difficult, consider focusing on high-quality carbohydrates (fiber, whole grains) if you cannot sustain strict low-carb intake.

High salt intake (from 2-3 sources) is significantly associated with higher odds of diabetes and overweight/obesity in older adults.

If you are over 40 and live in an urban area, reducing salt intake from multiple sources (cooking, table, snacks) can help lower your risk of diabetes and obesity. Try to limit added salt and choose less processed foods.

In women, higher intake of total protein, animal protein, polyunsaturated fatty acids (PUFA), and n-3 fatty acids is associated with decreased all-cause mortality, whereas higher carbohydrate intake is associated with increased all-cause mortality.

If you are a woman over 40, prioritizing adequate protein (especially animal sources like fish or lean meat), healthy fats (PUFA and n-3), and moderating carbohydrate intake may support longevity. If you are a man, ensuring sufficient fat intake (including saturated and monounsaturated fats) might be beneficial. These findings suggest that sex-specific dietary patterns, rather than one-size-fits-all macronutrient ratios, may be optimal for healthspan.

In men, higher intake of total fat, saturated fatty acids (SFA), monounsaturated fatty acids (MUFA), and n-6 fatty acids is associated with decreased all-cause mortality.

If you are a man over 40, ensuring adequate intake of fats, including saturated and monounsaturated fats (from sources like meat, cheese, nuts), may support longevity. This does not mean overconsumption, but rather that fat restriction may not be necessary for men in the same way it is often recommended.

Substituting 3% of total energy intake from polyunsaturated fatty acids (PUFA) for carbohydrates (low or high glycemic index) or proteins (animal or vegetable) significantly reduces systolic blood pressure (SBP) in adults.

To potentially lower systolic blood pressure, try replacing 3% of your daily calories from saturated or monounsaturated fats with Polyunsaturated Fats (PUFA). This can be done by swapping some animal proteins or refined carbohydrates for PUFA-rich foods like fatty fish, walnuts, or sunflower oil. This swap should be done while keeping your total calorie intake the same. Note that this benefit was observed in men for SBP reduction and in women for hypertension risk reduction in this specific population.

Substituting Polyunsaturated Fatty Acids (PUFA) for carbohydrates (LGI or HGI) significantly reduces the odds of developing hypertension.

To potentially lower your risk of developing hypertension, consider replacing 3% of your daily calories from carbohydrates (both low and high glycemic index) with Polyunsaturated Fats (PUFA). This is particularly beneficial for women in this study. Ensure you keep your total calorie intake the same by reducing carbs rather than adding extra fat. Good sources of PUFA include fatty fish, walnuts, and sunflower oil.

Moderate adherence to a nutrient pattern rich in unsaturated fatty acids and vitamin E is associated with lower all-cause and cancer mortality, whereas high adherence is associated with increased cerebrovascular disease mortality.

Include unsaturated fats (like those in fish and vegetable oils) and vitamin E sources in your diet, but avoid excessive consumption. The study suggests that moderate intake lowers cancer and all-cause mortality, while very high intake might increase stroke risk, possibly due to how these fats are prepared (e.g., deep-frying) or paired with other high-fat foods.

Replacing saturated fatty acids with polyunsaturated fatty acids reduces the risk of coronary heart disease, whereas replacing saturated fat with carbohydrates does not.

Don't just cut fat; look at what you eat instead. If you reduce saturated fats (like butter or fatty meat), replace them with polyunsaturated fats (like vegetable oils, nuts, or seeds) to lower heart disease risk. Replacing them with carbohydrates (like bread or sugar) does not provide the same benefit.

Higher animal protein intakes (1.2-2.2 g/kg body weight) do not harm bone health and may be beneficial, provided calcium intake is adequate.

You can safely consume high amounts of protein (1.2-2.2 g/kg body weight) to support muscle and bone health. Ensure you are eating enough calcium (dairy, leafy greens, fortified foods) to offset any urinary calcium loss. This combination supports bone strength without the feared bone loss associated with the 'acid-ash' theory.

Cow milk consumption is associated with lower risk of mortality and major cardiovascular disease events, and can improve insulin resistance, particularly when derived from pasture-fed cows with higher CLA and n-3 PUFA content.

Incorporating cow milk, particularly from pasture-fed cows, can support cardiovascular health and insulin resistance. The benefits are linked to higher levels of CLA and n-3 fatty acids in pasture-fed milk. Choose high-quality dairy sources for maximum metabolic benefit.

Plant-based diets require higher total protein intake than the standard RDA to achieve equivalent amino acid utilization compared to mixed diets.

If you eat a plant-based diet, the standard protein recommendation might not be enough because plant proteins are harder for your body to use. You likely need to eat more total protein than the standard guideline suggests to maintain muscle and health. Focus on variety and ensure you are getting enough calories to meet these higher protein needs.

Replacing saturated fatty acids (SFA) with polyunsaturated (PUFA) or monounsaturated fatty acids (MUFA) reduces serum HDL-C, whereas replacing carbohydrates with these fatty acids increases HDL-C.

If you want to raise your HDL-C through diet, replacing carbohydrates (especially refined carbs) with unsaturated fats (like olive oil or nuts) is more effective than replacing saturated fats (like butter) with those same unsaturated fats. However, remember that HDL-C is just a number; the functional quality of your HDL particles is what ultimately matters for heart health.

Orlistat (60mg OTC or 120mg Rx) is a pharmacological option that reduces fat absorption but has significant gastrointestinal side effects (steatorrhea) that can be managed through patient education.

Orlistat (60mg OTC, 120mg Rx) inhibits fat absorption. It is less effective than GLP-1s. Key to adherence is educating patients to eat a low-fat diet to avoid steatorrhea. It is an adjunct to lifestyle changes.

Consuming lipids with a higher solid fat content (SFC) and crystalline structure significantly delays postprandial plasma triglyceride (TAG) increases and reduces the total incremental area under the curve compared to compositionally identical liquid lipids.

If you are concerned about post-meal blood fat spikes, the physical form of the fat you eat matters. Solid fats (like those in butter or palm stearin) digest more slowly and may result in lower post-meal triglyceride levels compared to liquid oils (like olive or canola oil), even if they have the same fatty acid makeup. This suggests that food structure and fat state are important levers for metabolic health.

A low-carbohydrate diet improves cardiovascular risk markers (specifically HDL cholesterol and triglycerides) more effectively than a conventional diet, even when weight loss differences are accounted for.

Switching to a low-carb diet can significantly improve your HDL ('good') cholesterol and lower triglycerides more than a standard low-fat diet. While LDL cholesterol might rise initially, it often stabilizes over time. This suggests that focusing solely on fat intake might be less important than the overall macronutrient balance and its effect on your lipid profile.

Low-carbohydrate diets produce greater weight loss, improved HDL, and lower triglycerides compared to low-fat diets over 6-12 months, but result in higher LDL and total cholesterol levels.

If you are choosing between low-carb and low-fat for weight loss, low-carb diets tend to yield slightly better results (about 1.3 kg more loss) and improve triglycerides and HDL more effectively over 6-12 months. However, be aware that low-carb diets may raise LDL and total cholesterol. If you have high baseline LDL, a low-fat diet might be safer for your lipid profile, even if weight loss is slightly less. Monitor your lipids regardless of the diet chosen.

Low-carbohydrate diets improve triglyceride levels more than balanced-carbohydrate diets in overweight/obese adults without type 2 diabetes, regardless of weight loss duration.

If you have high triglycerides, a low-carb diet may help lower them more effectively than a balanced diet, even if your weight loss is similar.

Tirzepatide treatment for obesity results in a 3:1 ratio of fat mass reduction to fat-free mass (FFM) reduction, leading to improved body composition rather than proportional lean tissue loss.

If you are using Tirzepatide for weight loss, you can expect your body composition to improve favorably. The medication targets fat stores more aggressively than lean muscle tissue, resulting in roughly three times more fat loss than muscle loss. This helps maintain your metabolic rate and physical function better than traditional caloric restriction alone, which often depletes lean mass proportionally.

Higher intake of cereal fiber is inversely associated with the risk of NIDDM in men, independent of other fiber types and dietary confounders.

Increase your intake of cereal fiber by choosing whole grains over refined grains. Aim for more than 8.1 grams of cereal fiber per day to significantly lower your risk of type 2 diabetes.

Training with low carbohydrate availability ('train low') enhances metabolic adaptations (e.g., enzyme activity) but does not currently provide convincing evidence for improved athletic performance compared to high carbohydrate availability strategies.

Don't intentionally train with low glycogen to 'trick' your body into getting faster. While it might change some muscle markers, it won't make you faster and might make your hard workouts worse. Instead, fuel high-intensity sessions well. You can naturally train with lower carbs during easy recovery days or early morning sessions if convenient, but don't force it for performance gains.

Higher intake of n-3 fatty acids (from fish or plant sources) substantially lowers the risk of cardiovascular mortality.

Include sources of n-3 fatty acids, such as fatty fish or plant sources (like walnuts or flaxseed), in your diet to support heart health and reduce mortality risk.

The protective effect of a Mediterranean dietary pattern on coronary heart disease is stronger in women with a BMI of 25 kg/m2 or higher compared to those with a BMI below 25 kg/m2.

If you are overweight or obese, adopting a Mediterranean-style diet may offer even greater protection against heart disease than it does for those with a normal BMI. Focus on plant-based foods, healthy fats, and limiting processed meats.

High consumption of ultra-processed foods is strongly and linearly associated with excessive intake of added sugars, with ultra-processed foods contributing nearly 90% of added sugar energy in the US diet.

To significantly reduce your added sugar intake, focus on minimizing ultra-processed foods. These items, which make up nearly 60% of US calories, are responsible for almost 90% of added sugars. Look for products with long ingredient lists containing additives, emulsifiers, and added sugars, and prioritize whole or minimally processed foods instead.

Higher intake of linoleic acid (a polyunsaturated fat) is associated with a lower risk of type 2 diabetes, specifically in men under 65 years of age and those with a BMI less than 25 kg/m2.

If you are a man under 65 and have a healthy weight (BMI <25), increasing your intake of linoleic acid (found in vegetable oils like sunflower, safflower, and corn oil) may help lower your risk of type 2 diabetes. This benefit was not seen in older or overweight men, so age and weight matter when considering this dietary change.