Browse the evidence

Low-carbohydrate diets improve triglycerides and HDL more effectively than low-fat diets, while low-fat diets are more effective at reducing LDL cholesterol.

If your main issue is high triglycerides or low HDL, a low-carb diet may improve your heart health markers more than a low-fat diet. If your main issue is high LDL cholesterol, a low-fat diet might be more effective for that specific number. Consult a professional to interpret your full lipid panel.

Long-term adherence to a high-quality low-carbohydrate diet (HQ-LCDS) is associated with favorable changes in HDL cholesterol and triglycerides, whereas a low-quality low-carbohydrate diet (LQ-LCDS) is associated with adverse changes in fasting glucose.

If you follow a low-carbohydrate diet, ensure the carbohydrates you do eat are high-quality (high fiber, whole foods). Avoid replacing healthy carbs with refined grains or added sugars, as this can negatively impact blood glucose levels. Prioritizing high-quality carbs in your low-carb pattern improves HDL and lowers triglycerides.

High-carbohydrate diets (≥45% TDCI) are superior to low-carbohydrate diets for reducing LDL cholesterol in healthy adults under energy-matched conditions.

If your primary concern is lowering LDL cholesterol, and you are willing to eat more carbohydrates (at least 45% of your calories), this may be more effective than a low-carb diet, provided you keep your total calorie intake the same.

Low-carbohydrate diets provide short-term improvements in HbA1c and body weight but lack consistent long-term superiority over balanced diets.

Low-carb diets can be useful for short-term metabolic improvement in selected patients, but require clinical monitoring. They are not superior to balanced diets in the long term for everyone.

Replacing saturated fatty acids (SFAs) with polyunsaturated fatty acids (PUFAs) significantly reduces the risk of coronary heart disease (CHD) and fatal CHD.

To lower your heart disease risk, swap some of the saturated fats in your diet (like butter or fatty meats) for polyunsaturated fats (like vegetable oils, nuts, or seeds). Aim to replace about 5% of your total calories from saturated fat with these healthier fats. This change is linked to a significant drop in heart disease risk.

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.

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.

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.

High intake of refined carbohydrates and high glycemic index foods promotes oxidative stress and chronic inflammation via NF-κB-mediated signaling, contributing to insulin resistance and metabolic syndrome.

Focus on reducing refined carbohydrates and high glycemic index foods (like white rice and added sugars) to lower oxidative stress and inflammation. Opt for lower glycemic index options to help manage blood sugar and metabolic health, especially if you are overweight or have metabolic syndrome.

High intake of processed meats, particularly those cooked at high temperatures, increases the formation of genotoxic and carcinogenic compounds like heterocyclic amines and N-nitroso compounds, contributing to oxidative stress and colorectal cancer risk.

Limit intake of processed meats and avoid cooking red meat at high temperatures (e.g., grilling, charring) to reduce the formation of carcinogenic compounds and oxidative stress. Opt for fresh, unprocessed meats and gentler cooking methods.

Replacing saturated fatty acids (SFA) with monounsaturated fatty acids (MUFA) lowers LDL cholesterol but has an unclear or neutral effect on clinical cardiovascular disease events and mortality compared to SFA.

Swapping saturated fats for monounsaturated fats (like olive oil) will lower your bad (LDL) cholesterol. However, this swap alone may not be enough to prevent heart attacks or strokes. For better protection against heart disease, prioritize replacing saturated fats with polyunsaturated fats (like fish oils, walnuts) or whole grains instead.