A healthy diet is a diet that helps maintain or improve overall health. A healthy diet provides the body with essential nutrition: fluid, macronutrients, micronutrients, and adequate food energy.
A healthy diet may contain fruits, vegetables, and whole grains, and may include little to no processed food or sweetened beverages. The requirements for a healthy diet can be met from a variety of plant-based and animal-based foods, although a non-plant source of vitamin B12 is needed for those following a vegan diet. Various nutrition guides are published by medical and governmental institutions to educate individuals on what they should be eating to be healthy. Nutrition facts labels are also mandatory in some countries to allow consumers to choose between foods based on the components relevant to health.
World Health Organization
The World Health Organization (WHO) makes the following five recommendations with respect to both populations and individuals:
- Maintain a healthy weight by eating roughly the same number of calories that your body is using.
- Limit intake of fats. Not more than 30% of the total calories should come from fats. Prefer unsaturated fats to saturated fats. Avoid trans fats.
- Eat at least 400 grams of fruits and vegetables per day (potatoes, sweet potatoes, cassava and other starchy roots do not count). A healthy diet also contains legumes (e.g. lentils, beans), whole grains and nuts.
- Limit the intake of simple sugars to less than 10% of calorie (below 5% of calories or 25 grams may be even better).
- Limit salt / sodium from all sources and ensure that salt is iodized. Less than 5 grams of salt per day can reduce the risk of cardiovascular disease.
The WHO has stated that insufficient vegetables and fruit is the cause of 2.8% of deaths worldwide.[failed verification]
Other WHO recommendations include:
- ensuring that the foods chosen have sufficient vitamins and certain minerals;
- avoiding directly poisonous (e.g. heavy metals) and carcinogenic (e.g. benzene) substances;
- avoiding foods contaminated by human pathogens (e.g. E. coli, tapeworm eggs);
- and replacing saturated fats with polyunsaturated fats in the diet, which can reduce the risk of coronary artery disease and diabetes.[failed verification]
United States Department of Agriculture
The Dietary Guidelines for Americans by the United States Department of Agriculture (USDA) recommends three healthy patterns of diet, summarized in the table below, for a 2000 kcal diet.
The guidelines emphasize both health and environmental sustainability and a flexible approach. The committee that drafted it wrote: “The major findings regarding sustainable diets were that a diet higher in plant-based foods, such as vegetables, fruits, whole grains, legumes, nuts, and seeds, and lower in calories and animal-based foods is more health promoting and is associated with less environmental impact than is the current U.S. diet. This pattern of eating can be achieved through a variety of dietary patterns, including the “Healthy U.S.-style Pattern”, the “Healthy Vegetarian Pattern” and the “Healthy Mediterranean-style Pattern”. Food group amounts are per day, unless noted per week.
|Food group/subgroup (units)||U.S. style||Vegetarian||Med-style|
|Fruits (cup eq)||2||2||2.5|
|Vegetables (cup eq)||2.5||2.5||2.5|
|Grains (oz eq)||6||6.5||6|
|Dairy (cup eq)||3||3||2|
|Protein Foods (oz eq)||5.5||3.5||6.5|
|Meat (red and processed)||12.5/wk||—||12.5/wk|
|Processed Soy (including tofu)||0.5/wk||8/wk||0.5/wk|
|Solid fats limit (grams)||18||21||17|
|Added sugars limit (grams)||30||36||29|
American Heart Association / World Cancer Research Fund / American Institute for Cancer Research
The American Heart Association, World Cancer Research Fund, and American Institute for Cancer Research recommend a diet that consists mostly of unprocessed plant foods, with emphasis on a wide range of whole grains, legumes, and non-starchy vegetables and fruits. This healthy diet includes a wide range of non-starchy vegetables and fruits which provide different colors including red, green, yellow, white, purple, and orange. The recommendations note that tomato cooked with oil, allium vegetables like garlic, and cruciferous vegetables like cauliflower, provide some protection against cancer. This healthy diet is low in energy density, which may protect against weight gain and associated diseases. Finally, limiting consumption of sugary drinks, limiting energy rich foods, including “fast foods” and red meat, and avoiding processed meats improves health and longevity. Overall, researchers and medical policy conclude that this healthy diet can reduce the risk of chronic disease and cancer.
It is recommended that children consume less than 25 grams of added sugar (100 calories) per day. Other recommendations include no extra sugars in those under 2 years old and less than one soft drink per week. As of 2017, decreasing total fat is no longer recommended, but instead, the recommendation to lower risk of cardiovascular disease is to increase consumption of monounsaturated fats and polyunsaturated fats, while decreasing consumption of saturated fats.
Harvard School of Public Health
The Nutrition Source of Harvard School of Public Health makes the following 10 recommendations for a healthy diet:
- Choose good carbohydrates: whole grains (the less processed the better), vegetables, fruits and beans. Avoid white bread, white rice, and the like as well as pastries, sugared sodas, and other highly processed food.
- Pay attention to the protein package: good choices include fish, poultry, nuts, and beans. Try to avoid red meat.
- Choose foods containing healthy fats. Plant oils, nuts, and fish are the best choices. Limit consumption of saturated fats, and avoid foods with trans fat.
- Choose a fiber-filled diet which includes whole grains, vegetables, and fruits.
- Eat more vegetables and fruits—the more colorful and varied, the better.
- Include adequate amounts of calcium in the diet; however, milk is not the best or only source. Good sources of calcium are collards, bok choy, fortified soy milk, baked beans, and supplements containing calcium and vitamin D.
- Prefer water over other beverages. Avoid sugary drinks, and limit intake of juices and milk. Coffee, tea, artificially-sweetened drinks, 100% fruit juices, low-fat milk and alcohol can fit into a healthy diet but are best consumed in moderation. Sports drinks are recommended only for people who exercise more than an hour at a stretch to replace substances lost in sweat.
- Limit salt intake. Choose more fresh foods, instead of processed ones.
- Drink alcohol in moderation. Doing so has health benefits, but is not recommended for everyone.
- Consider intake of daily multivitamin and extra vitamin D, as these have potential health benefits.
Other than nutrition, the guide recommends frequent physical exercise and maintaining a healthy body weight.
David L. Katz, who reviewed the most prevalent popular diets in 2014, noted: