Browse the evidence

A low-carbohydrate diet (LCD) results in lower subjective hunger (being bothered by hunger) compared to a low-fat diet (LFD) over a 2-year period.

If you switch to a low-carb diet, you may find that hunger is less of a bother compared to a low-fat diet. This doesn't mean you won't feel hunger, but the distress associated with it may be lower, potentially aiding long-term adherence.

Animal protein provides a statistically significant advantage over plant protein for increasing percent lean mass, particularly in adults under 50 years of age, while absolute lean mass and muscle strength gains are generally equivalent between sources when total protein intake is adequate.

If you are under 50, choosing animal protein over plant protein may give you a slight edge in preserving lean tissue relative to your body weight, but it won't necessarily add more absolute muscle or strength if you eat enough total protein. For older adults, the source matters less than hitting your total protein targets. Focus on getting enough protein daily rather than obsessing over animal vs. plant source for strength outcomes.

Post-exercise protein and carbohydrate co-ingestion enhances net muscle protein balance and signaling (mTOR/p70S6k) after resistance training, but does not consistently improve subsequent endurance performance compared to carbohydrate alone.

After resistance training, consuming ~6g of protein with carbohydrates can help your muscles build protein. However, for endurance athletes, adding protein to a carb recovery drink doesn't seem to improve your next workout compared to just carbs. Focus on getting enough total protein throughout the day rather than stressing over the exact post-workout mix.

Sugars are not inherently harmful; their effect on cardiometabolic health depends on energy balance and food source. Sugar-sweetened beverages cause harm due to excess energy, while sugars in high-quality foods (fruit, yogurt, whole grain cereals) provide benefit when substituted for refined starches.

Do not fear sugars in whole foods. Fruit, yogurt, and whole grain cereals containing sugars are beneficial when they replace refined starches. Avoid sugar-sweetened beverages which provide excess energy without nutrients.

Low muscle glycogen availability during prolonged aerobic exercise increases net skeletal muscle protein degradation and decreases protein synthesis, resulting in a more negative whole-body protein balance compared to high glycogen conditions.

If you are doing long-duration cardio (e.g., >1 hour) and your glycogen stores are low, your body will break down more muscle protein and build less of it. To protect muscle, consider consuming carbohydrates before or during the exercise, or ensure your post-exercise protein intake is sufficient to counteract this increased breakdown.

Higher consumption of whole fat dairy (at least two servings per day) is associated with a lower prevalence of metabolic syndrome and a lower incidence of hypertension and diabetes compared to zero intake.

If you consume dairy, choosing whole fat options (like whole milk, full-fat yogurt, or cheese) and consuming at least two servings daily is associated with a lower risk of developing metabolic syndrome, high blood pressure, and type 2 diabetes compared to not consuming dairy or consuming only low fat dairy. This association holds across diverse global populations, suggesting that the fat content in dairy may not be detrimental and might even be beneficial for metabolic health when compared to low fat alternatives.

In uncomplicated human disuse states (bed rest, immobilization), the dominant mechanism driving muscle atrophy is a significant reduction in muscle protein synthesis (MPS), not an increase in muscle protein breakdown (MPB).

If you are immobilized or inactive, your muscles shrink primarily because protein synthesis drops by about 50%, not because breakdown increases. To prevent this, you must actively stimulate muscle protein synthesis through low-volume resistance exercise or amino acid/protein intake, as the body's natural response to inactivity is to shut down muscle building.

Incretin-mimetic drugs (IMDs) such as semaglutide and tirzepatide cause significant skeletal muscle mass loss (≥10%) during rapid weight reduction, a loss comparable to 20 years of age-related decline.

If you are taking GLP-1 or GIP/GLP-1 drugs, expect to lose muscle along with fat. This is not just 'water weight'; it is functional tissue. To mitigate this, you must prioritize protein intake and engage in resistance training, as these are the only proven strategies to preserve muscle during rapid weight loss.

An isocaloric ketogenic diet (5% carbohydrate, 80% fat) increases fasting inflammatory markers (CRP, adiponectin) and cholesterol (total, LDL, HDL) compared to a baseline diet (50% carbohydrate, 35% fat) in men with overweight or class I obesity.

If you switch to a strict ketogenic diet (80% fat, 5% carbs) while keeping your calories the same, expect your cholesterol (including LDL and HDL) and inflammatory marker (CRP) levels to rise compared to a standard diet. This effect was observed in men with overweight or obesity over 4 weeks. Monitor your lipids and inflammation if you adopt this diet.

An isocaloric ketogenic diet significantly lowers fasting triglycerides but raises fasting total, HDL, and LDL cholesterol compared to a baseline diet in men with overweight or obesity.

Switching to a ketogenic diet will likely lower your triglycerides but raise your total, LDL, and HDL cholesterol. This mixed effect means you should monitor your full lipid panel, not just triglycerides, to assess cardiovascular risk.

Reducing dietary fat intake to lower levels spontaneously reduces daily energy consumption by approximately 270 kcal, effectively resetting energy balance and preventing significant weight gain.

You can reduce your calorie intake without counting calories by choosing foods with lower fat content. This often leads to eating less naturally. For example, swapping high-fat snacks for lower-fat alternatives can save you hundreds of calories a day without feeling deprived.

Global dietary patterns are suboptimal, with high intake of sodium, processed/red meat, and sugary beverages, and low intake of nuts, seeds, milk, and whole grains, contributing to 11 million deaths and 255 million DALYs annually.

Focus on increasing intake of whole grains, fruits, nuts, seeds, and milk, while reducing sodium, sugary beverages, and processed/red meat. Recognize that affordability is a major barrier, so prioritize accessible healthy options within your budget and advocate for systemic changes to make healthy food cheaper.

Shifting from nutrient-based to food-based dietary guidelines is supported by evidence that promotes predominantly plant-based diets for sustainable and healthy food systems.

Adopt a predominantly plant-based diet, focusing on whole foods rather than isolated nutrients. Advocate for policy changes to make healthy food more affordable and accessible, especially in low- and middle-income countries.

High intake of plant-based essential polyunsaturated fatty acids (ePUFAs), specifically linoleic acid (LA) and alpha-linolenic acid (ALA), is associated with increased lean body mass and reduced central adiposity, whereas marine-derived long-chain n-3 PUFAs (EPA/DHA) show no significant impact on body composition.

To support lean mass and reduce central fat, prioritize dietary sources of plant-based polyunsaturated fats (like linoleic acid from vegetable oils and alpha-linolenic acid from flax/nuts) over marine-derived fish oil supplements. While fish oil has cardiovascular benefits, current evidence suggests it does not significantly alter body composition in adults.

Supplementation with omega-3 fatty acids significantly reduces triglycerides in individuals with familial hypercholesterolemia, but has no significant impact on total or LDL cholesterol.

For FH patients, high-dose omega-3s (4-6g/day) are effective at lowering triglycerides. However, do not expect them to significantly lower LDL cholesterol. They are best used as an adjunct for triglyceride management, not as a primary cholesterol-lowering strategy.

In Korean adults, an energy intake distribution of 50–60% carbohydrates, 30–40% fat, and 20–30% protein is associated with the lowest all-cause mortality risk.

For Korean adults, aiming for 50-60% of calories from carbohydrates, 30-40% from fat, and 20-30% from protein is associated with the longest life expectancy. This suggests revising current dietary guidelines to lower the recommended carbohydrate range and potentially increase healthy fat intake within this optimal window.

Strict weight reduction diets (Low-carb, Ketogenic, Intermittent Fasting, VLCD) significantly increase the risk of micronutrient deficiencies compared to balanced or low-fat diets.

If you use a restrictive diet like Keto or Intermittent Fasting to lose weight, you are at high risk for missing essential nutrients. You must actively supplement or carefully plan your meals to include these nutrients, as the diet itself limits your intake.

Long-term adherence to a low-carbohydrate diet (LCD) starting in young adulthood is associated with an increased risk of coronary artery calcium (CAC) progression in middle age, particularly when carbohydrates are replaced by animal-based protein and fat rather than plant-based sources.

If you follow a low-carbohydrate diet, especially one that started in your 20s or 30s, be mindful of what replaces the carbohydrates. This study suggests that replacing carbs with animal proteins and fats (like red meat, butter, cheese) is linked to increased coronary artery calcium progression, a marker of heart disease risk. To mitigate this risk, consider replacing carbohydrates with plant-based proteins and fats (like nuts, seeds, legumes, vegetables) instead. Long-term animal-based low-carb diets should be approached with caution regarding cardiovascular health.

Excess caloric intake, particularly from carbohydrates (fructose/glucose) and saturated fats, drives de novo lipogenesis and hepatic fat accumulation, whereas unsaturated fats (omega-3) may reduce liver fat.

Focus on reducing added sugars (especially fructose/sweetened beverages) and saturated fats. Replace them with unsaturated fats (like omega-3s) and whole food carbohydrates. Total calories matter, but what you eat matters more for your liver.

Consuming a higher variety of protein sources (from 8 major food groups) at their respective appropriate quantity windows is inversely associated with the risk of new-onset hypertension.

To lower your risk of high blood pressure, focus on eating a wide variety of protein sources—such as grains, red meat, poultry, fish, eggs, and legumes—rather than just increasing total protein. Ensure you are eating these sources in moderate, balanced amounts, as both too little and too much of specific types can increase risk. Aim for a diverse diet that includes small portions from each of these major protein groups.

There is no single 'appropriate' amount for all protein sources; each source (red meat, poultry, fish, etc.) has a unique non-linear relationship with hypertension risk, requiring source-specific quantity windows.

Don't just focus on hitting a total protein number. Pay attention to what kind of protein you are eating. Some sources like red meat and poultry may increase risk if eaten in excess, while others like legumes and eggs may offer protection. A balanced mix of moderate amounts from various sources is key.

Replacing saturated fatty acids (SFAs) with polyunsaturated fatty acids (PUFAs) reduces cardiovascular disease risk, whereas replacing SFAs with carbohydrates or proteins provides no benefit.

If you want to lower your cardiovascular risk by changing your fat intake, do not just cut saturated fats. You must replace them with polyunsaturated fats (like those found in vegetable oils, nuts, and fish). Replacing saturated fats with carbohydrates or proteins does not offer the same cardiovascular protection.

Adherence to a healthy low-carbohydrate diet (low low-quality carbs, high unsaturated fat, high plant protein) is associated with marginally lower total mortality (HR 0.95) in middle-aged and older adults, whereas overall or unhealthy LCDs (high saturated fat/animal protein) increase mortality risk.

If you follow a low-carbohydrate diet, prioritize unsaturated fats (like olive oil, nuts) and plant proteins (legumes, grains) while minimizing saturated fats and refined carbohydrates. Simply reducing carbs without improving food quality may increase your risk of death.

Adherence to a healthy low-fat diet (low saturated fat, high high-quality carbohydrates, high plant protein) is associated with significantly lower total (HR 0.82), cardiovascular (HR 0.84), and cancer (HR 0.82) mortality in middle-aged and older adults.

Adopt a low-fat diet that emphasizes high-quality carbohydrates (whole grains, fruits, vegetables) and plant proteins (legumes, nuts) while strictly limiting saturated fats. This pattern is associated with an 18% lower risk of death from all causes, heart disease, and cancer in older adults.