Browse the evidence

US adults significantly improved diet quality between 1999 and 2016 by decreasing low-quality carbohydrates (primarily added sugars) and increasing high-quality carbohydrates (primarily whole grains), plant protein, and polyunsaturated fats.

Focus on swapping low-quality carbohydrates for high-quality ones. Specifically, reduce added sugars and increase intake of whole grains, plant-based proteins (like nuts and whole grains), and polyunsaturated fats. While overall diet quality has improved, these specific swaps are the key drivers of that improvement.

An isocaloric Mediterranean diet intervention significantly lowers total, LDL, and HDL plasma cholesterol in overweight and obese adults within 4 weeks, independent of energy intake or physical activity changes.

If you are overweight or obese, switching to a Mediterranean dietary pattern can lower your total and LDL cholesterol within just 4 weeks, even if you do not lose weight or change your exercise habits. Focus on replacing meat and refined cereals with fruits, vegetables, whole grains, legumes, and nuts. The greater your adherence to this pattern, the more your cholesterol drops.

Restricting total carbohydrate intake to less than 130 g/day is not recommended for the management of diabetes.

Do not restrict your carbohydrate intake to less than 130 grams per day. Your brain needs glucose, and restricting carbs this low may deprive you of essential nutrients like fiber and vitamins. Aim for 45-65% of your calories from carbohydrates, focusing on high-quality sources.

Orlistat (60-120 mg three times daily) combined with a hypocaloric diet produces significantly greater weight loss and improved cardiovascular risk factors compared to diet and placebo alone.

Take orlistat (60mg or 120mg) with your three main meals if you consume fat. Combine this with a calorie-controlled diet for the first year, then switch to a maintenance diet. Expect significant weight loss and improved cholesterol/blood pressure, but be prepared for mild, temporary gastrointestinal side effects if you eat too much fat.

Replacing 5% of total energy intake from saturated fats with polyunsaturated fatty acids (PUFA) or monounsaturated fatty acids (MUFA) is associated with a significant reduction in total mortality.

To lower your risk of death, focus on swapping saturated fats (found in red meat, butter, full-fat dairy) with unsaturated fats (found in olive oil, nuts, seeds, fish). Specifically, aim to replace about 5% of your daily calories from saturated fats with an equal amount of calories from polyunsaturated or monounsaturated fats. This swap is linked to a 13-27% lower risk of dying from any cause. Do not replace these fats with refined carbohydrates like white bread or sugar, as that offers no mortality benefit.

Higher intake of trans-fatty acids (TFA) is associated with increased total mortality and cause-specific mortality (particularly cardiovascular and neurodegenerative diseases).

Avoid industrial trans fats, which are found in partially hydrogenated oils used in some fried foods and baked goods. Higher intake of trans fats is linked to a 13% higher risk of total mortality and a 20% higher risk of cardiovascular disease mortality. Check labels for 'partially hydrogenated oils' and minimize consumption.

For prolonged endurance exercise (2-3 hours), ingesting 60 g/h of a single carbohydrate source (like glucose or maltodextrin) is the recommended maximum for oxidation, as intestinal transporters (SGLT1) become saturated.

For races lasting 2 to 3 hours, aim to consume 60 grams of carbohydrates per hour using a single source like glucose or maltodextrin. This is the maximum amount your gut can typically absorb and use for energy without causing stomach upset.

For ultra-endurance exercise (>2.5 hours), ingesting 90 g/h of multiple transportable carbohydrates (e.g., glucose and fructose in a 2:1 ratio) maximizes exogenous oxidation rates and improves performance compared to single-source carbohydrates.

For races longer than 2.5 hours, consume 90 grams of carbohydrates per hour using a mix of glucose and fructose (ideally in a 2:1 ratio). This allows your body to absorb and use more fuel than single-source carbs, delaying fatigue.

Partial replacement of saturated fatty acids (SFA) with polyunsaturated (PUFA) or monounsaturated fatty acids (MUFA) significantly lowers fasting total and LDL cholesterol concentrations.

To improve your cholesterol, swap saturated fats (found in butter, fatty meats, full-fat dairy) for unsaturated fats (found in olive oil, nuts, seeds, fish). You don't need to eliminate fat entirely; focus on the type. This substitution is strongly supported by evidence to lower LDL cholesterol.

Partial replacement of saturated fat with polyunsaturated fat (PUFA) decreases the risk of cardiovascular disease (CVD), particularly in men.

To lower your risk of heart disease, replace saturated fats (butter, fatty meats) with polyunsaturated fats (vegetable oils, nuts, fish). This change is strongly linked to a lower risk of cardiovascular events, especially for men.

Reducing dietary saturated fatty acid (SFA) intake significantly lowers plasma total and LDL cholesterol levels in healthy adults across diverse demographic subgroups.

To lower your LDL cholesterol, gradually replace saturated fats (found in meats, butter, full-fat dairy) with unsaturated fats and carbohydrates while keeping total calories and dietary cholesterol constant. Aim for a diet where saturated fats make up less than 10% of your total calories. This change is effective for men, women, and people of all races.

Reducing total dietary carbohydrate content lowers triglycerides regardless of whether the carbohydrates are high or low glycemic index.

If you have high triglycerides, reducing your total carbohydrate intake (e.g., from 58% of calories to 40%) is an effective strategy, regardless of whether you choose high or low glycemic index carbs. This reduction lowers triglycerides significantly without needing to focus on glycemic index alone.

Postexercise carbohydrate ingestion at 1.2 g · kg–1 · hr–1 maximizes muscle glycogen synthesis rates, and adding protein does not further increase synthesis rates at this dosage.

To maximize glycogen recovery after intense exercise, consume 1.2 grams of carbohydrate per kilogram of body weight per hour, split into doses every 15-30 minutes. You do not need to add protein to speed this up if you are hitting this carbohydrate target. However, if you cannot eat that much carbohydrate, adding 0.2-0.4 g/kg/hr of protein will help you achieve the same glycogen replenishment rate with less total carbohydrate.

Macronutrient composition (low-carb vs. low-fat) has no significant difference on weight loss outcomes when total caloric intake and adherence are controlled.

Don't obsess over whether you should be low-carb or low-fat. The most important factor is that you eat fewer calories than you burn. You can achieve this with almost any dietary pattern (Mediterranean, low-carb, low-fat) as long as you stick to it and maintain a calorie deficit.

Replacing carbohydrates with Monounsaturated Fat (MUFA) lowers HbA1c and HOMA-IR, but does not significantly improve insulin secretion capacity (AIR) compared to PUFA.

Swapping carbohydrates for Monounsaturated Fats (like olive oil or avocados) can help lower HbA1c and improve insulin resistance. However, if your goal is to maximize insulin secretion capacity, Polyunsaturated Fats (PUFA) may offer an additional benefit that MUFA does not.

Endurance training increases absolute rates of fat oxidation but does not change the relative balance of substrate utilization (CHO vs. fat) when exercise is performed at the same relative intensity (percentage of VO2max).

Endurance training makes you faster and allows you to burn more fat in absolute terms, but your body still relies primarily on carbohydrates for energy at any given percentage of your maximum effort. Do not expect training alone to make you a 'fat-burning machine' at high intensities.

Carriers of the BMI-increasing FTO rs9939609 minor allele exhibit a specific genetic predisposition to consume higher dietary protein, independent of total energy intake or BMI.

If you carry the FTO risk variant for obesity, you may have a biological tendency to prefer protein-rich foods. Instead of viewing this as a flaw, use it: structure your meals to be higher in protein. This aligns with your genetic appetite signals, potentially making it easier to manage satiety and body weight without strictly counting total calories.

High-fat and fasting diets increase lipid oxidation (LIPOX) and lower respiratory quotient (RQ), which is directly associated with increased circulating acylcarnitines and decreased glycerophospholipids, indicating a coordinated metabolic shift toward mitochondrial beta-oxidation.

When you eat a high-fat or fasted state, your body shifts to burning fat for fuel. This shift is measurable through specific blood markers (acylcarnitines) and breathing ratios (RQ). If you want to increase fat oxidation, reducing carbohydrate intake or fasting are effective strategies.

Macronutrient composition (carbohydrate vs fat vs protein ratios) does not significantly impact weight loss outcomes when total caloric intake is controlled, provided the diet is sustainable.

You do not need to follow a specific 'low-carb' or 'low-fat' diet to lose weight. Studies show that when calories are equal, the source of those calories (carbs vs fat vs protein) matters less for weight loss than the total amount. Focus on finding a dietary pattern you enjoy and can stick with long-term.

There is no universally superior diet (low-carb vs. low-fat) for long-term weight loss; both result in similar energy intake and weight loss outcomes when protein and calories are controlled.

Don't obsess over whether to cut carbs or fat. Both approaches work equally well for weight loss if you maintain a calorie deficit. Choose the dietary pattern that fits your lifestyle, preferences, and health markers (like blood sugar) best, as no single diet is superior for everyone.

Total fat intake is not significantly related to the risk of coronary heart disease in women; the type of fat is the critical determinant.

Do not focus on reducing the total amount of fat you eat. Instead, focus on the type of fat. Replacing saturated and trans fats with unsaturated fats (like those in olive oil, nuts, and fish) is the key to heart health, not simply eating less fat.

Global consumption of saturated fat and dietary cholesterol is generally within recommended limits, whereas intakes of polyunsaturated fats (omega-6, omega-3) and trans fats are suboptimal for public health.

Prioritize the quality of fats you eat over the total amount. Ensure your diet includes adequate sources of polyunsaturated fats (like fish, nuts, seeds, and vegetable oils) while keeping saturated fat and trans fat intakes low. Global averages show we are doing well on saturated fat/cholesterol but failing to get enough beneficial unsaturated fats.

Seafood omega-3 and plant omega-3 intakes are significantly below optimal levels for the majority of the global population.

Increase your intake of omega-3 fatty acids. Aim for at least 250 mg/day of seafood omega-3 and 1,100 mg/day of plant omega-3. This is a global public health priority as most people fall short.

Higher circulating and tissue levels of linoleic acid (LA), the primary dietary omega-6 fatty acid, are associated with a significantly lower risk of total cardiovascular disease, cardiovascular mortality, and ischemic stroke.

Focus on maintaining healthy levels of linoleic acid (LA) through your diet, as higher biomarker levels of LA are linked to lower risks of heart disease and stroke. This suggests that current dietary guidelines recommending omega-6 intake are supported by large-scale evidence, and you do not need to fear omega-6 fatty acids for causing heart disease.