A healthy diet is a diet that maintains or improves overall health. A healthy diet provides the body with essential nutrition: fluid, macronutrients such as protein, micronutrients such as vitamins, and adequate fibre and food energy. [2] [3]
A healthy diet may contain fruits, vegetables, and whole grains, and may include little to no ultra-processed foods or sweetened beverages. The requirements for a healthy diet can be met from a variety of plant-based and animal-based foods, although additional sources of vitamin B12 are needed for those following a vegan diet. [4] 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. [5] [6]
The World Health Organization (WHO) makes the following five recommendations with respect to both populations and individuals: [7]
The WHO has stated that insufficient vegetables and fruit is the cause of 2.8% of deaths worldwide. [10] [ failed verification ]
Other WHO recommendations include:
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. [11] [12] [13] These guidelines are increasingly adopted by various groups and institutions for recipe and meal plan development. [14]
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". [15] 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 |
Dark green | 1.5/wk | 1.5/wk | 1.5/wk |
Red/orange | 5.5/wk | 5.5/wk | 5.5/wk |
Starchy | 5/wk | 5/wk | 5/wk |
Legumes | 1.5/wk | 3/wk | 1.5/wk |
Others | 4/wk | 4/wk | 4/wk |
Grains (oz eq) | 6 | 6.5 | 6 |
Whole | 3 | 3.5 | 3 |
Refined | 3 | 3 | 3 |
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 |
Poultry | 10.5/wk | – | 10.5/wk |
Seafood | 8/wk | – | 15/wk |
Eggs | 3/wk | 3/wk | 3/wk |
Nuts/seeds | 4/wk | 7/wk | 4/wk |
Processed Soy (including tofu) | 0.5/wk | 8/wk | 0.5/wk |
Oils (grams) | 27 | 27 | 27 |
Solid fats limit (grams) | 18 | 21 | 17 |
Added sugars limit (grams) | 30 | 36 | 29 |
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 policymakers conclude that this healthy diet can reduce the risk of chronic disease and cancer. [16] [17]
It is recommended that children consume 25 grams or less of added sugar (100 calories) per day. [18] Other recommendations include no extra sugars in those under two years old and less than one soft drink per week. [18] 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. [19]
The Nutrition Source of Harvard School of Public Health (HSPH) makes the following dietary recommendations: [20]
Other than nutrition, the guide recommends staying active and maintaining a healthy body weight. [20]
David L. Katz, who reviewed the most prevalent popular diets in 2014, noted:
The weight of evidence strongly supports a theme of healthful eating while allowing for variations on that theme. A diet of minimally processed foods close to nature, predominantly plants, is decisively associated with health promotion and disease prevention and is consistent with the salient components of seemingly distinct dietary approaches. Efforts to improve public health through diet are forestalled not for want of knowledge about the optimal feeding of Homo sapiens but for distractions associated with exaggerated claims, and our failure to convert what we reliably know into what we routinely do. Knowledge in this case is not, as of yet, power; would that it were so. [27]
Marion Nestle expresses the mainstream view among scientists who study nutrition: [28] : 10
The basic principles of good diets are so simple that I can summarize them in just ten words: eat less, move more, eat lots of fruits and vegetables. For additional clarification, a five-word modifier helps: go easy on junk foods. Follow these precepts and you will go a long way toward preventing the major diseases of our overfed society—coronary heart disease, certain cancers, diabetes, stroke, osteoporosis, and a host of others.... These precepts constitute the bottom line of what seem to be the far more complicated dietary recommendations of many health organizations and national and international governments—the forty-one "key recommendations" of the 2005 Dietary Guidelines, for example. ... Although you may feel as though advice about nutrition is constantly changing, the basic ideas behind my four precepts have not changed in half a century. And they leave plenty of room for enjoying the pleasures of food. [29] : 22
Historically, a healthy diet was defined as a diet comprising more than 55% of carbohydrates, less than 30% of fat and about 15% of proteins. [30] This view is currently shifting towards a more comprehensive framing of dietary needs as a global need of various nutrients with complex interactions, instead of per nutrient type needs. [31]
A healthy diet in combination with being active can help those with diabetes keep their blood sugar in check. [32] The US CDC advises individuals with diabetes to plan for regular, balanced meals and to include more nonstarchy vegetables, reduce added sugars and refined grains, and focus on whole foods instead of highly processed foods. [33] Generally, people with diabetes and those at risk are encouraged to increase their fiber intake. [34]
A low-sodium diet is beneficial for people with high blood pressure. A 2008 Cochrane review concluded that a long-term (more than four weeks) low-sodium diet lowers blood pressure, both in people with hypertension (high blood pressure) and in those with normal blood pressure. [35]
The DASH diet (Dietary Approaches to Stop Hypertension) is a diet promoted by the National Heart, Lung, and Blood Institute (part of the NIH, a United States government organization) to control hypertension. A major feature of the plan is limiting intake of sodium, [36] and the diet also generally encourages the consumption of nuts, whole grains, fish, poultry, fruits, and vegetables while lowering the consumption of red meats, sweets, and sugar. It is also "rich in potassium, magnesium, and calcium, as well as protein".
The Mediterranean diet, which includes limiting consumption of red meat and using olive oil in cooking, has also been shown to improve cardiovascular outcomes. [37]
Healthy diets in combination with physical exercise can be used by people who are overweight or obese to lose weight, although this approach is not by itself an effective long-term treatment for obesity and is primarily effective for only a short period (up to one year), after which some of the weight is typically regained. [38] [39] A meta-analysis found no difference between diet types (low-fat, low-carbohydrate, and low-calorie), with a 2–4 kilograms (4.4–8.8 lb) weight loss. [40] This level of weight loss is by itself insufficient to move a person from an 'obese' body mass index (BMI) category to a 'normal' BMI.
Gluten, a mixture of proteins found in wheat and related grains including barley, rye, oat, and all their species and hybrids (such as spelt, kamut, and triticale), [41] causes health problems for those with gluten-related disorders, including celiac disease, non-celiac gluten sensitivity, gluten ataxia, dermatitis herpetiformis, and wheat allergy. [42] In these people, the gluten-free diet is the only available treatment. [43] [44] [45]
The ketogenic diet is a treatment to reduce epileptic seizures for adults and children when managed by a health care team. [46]
Preliminary research indicated that a diet high in fruit and vegetables may decrease the risk of cardiovascular disease and death, but not cancer. [47] Eating a healthy diet and getting enough exercise can maintain body weight within the normal range and reduce the risk of obesity in most people. [48] A 2021 scientific review of evidence on diets for lowering the risk of atherosclerosis found that: [49]
low consumption of salt and foods of animal origin, and increased intake of plant-based foods—whole grains, fruits, vegetables, legumes, and nuts—are linked with reduced atherosclerosis risk. The same applies for the replacement of butter and other animal/tropical fats with olive oil and other unsaturated-fat-rich oil. [...] With regard to meat, new evidence differentiates processed and red meat—both associated with increased CVD risk—from poultry, showing a neutral relationship with CVD for moderate intakes. [...] New data endorse the replacement of most high glycemic index (GI) foods with both whole grain and low GI cereal foods.
Scientific research is also investigating impacts of nutrition on health- and lifespans beyond any specific range of diseases.
Research suggests that increasing adherence to Mediterranean diet patterns is associated with a reduction in total and cause-specific mortality, extending health- and lifespan. [50] [51] [52] [53] Research is identifying the key beneficial components of the Mediterranean diet. [54] [55] Studies suggest dietary changes are a factor of national relative rises in life-span. [56]
Approaches to develop optimal diets for health- and lifespan (or "longevity diets") [57] include:
Moreover, not only do the components of diets matter but the total caloric content and eating patterns may also impact health – dietary restriction such as caloric restriction is considered to be potentially healthy to include in eating patterns in various ways in terms of health- and lifespan. [65] [66]
An unhealthy diet is a major risk factor for a number of chronic diseases including: high blood pressure, high cholesterol, diabetes, abnormal blood lipids, overweight/obesity, cardiovascular diseases, and cancer. [67] The World Health Organization has estimated that 2.7 million deaths each year are attributable to a diet low in fruit and vegetables during the 21st century. [68] Globally, such diets are estimated to cause about 19% of gastrointestinal cancer, 31% of ischaemic heart disease, and 11% of strokes, [6] thus making it one of the leading preventable causes of death worldwide, [69] and the 4th leading risk factor for any disease. [70] As an example, the Western pattern diet is "rich in red meat, dairy products, processed and artificially sweetened foods, and salt, with minimal intake of fruits, vegetables, fish, legumes, and whole grains," contrasted by the Mediterranean diet which is associated with less morbidity and mortality. [71]
Dietary patterns that lead to non-communicable diseases generate productivity losses. A true cost accounting (TCA) assessment on the hidden impacts of agrifood systems estimated that unhealthy dietary patterns generate more than USD 9 trillion in health-related hidden costs in 2020, which is 73 percent of the total quantified hidden costs of global agrifood systems (USD 12.7 trillion). Globally, the average productivity losses per person from dietary intake is equivalent to 7 percent of GDP purchasing power parity (PPP) in 2020; low-income countries report the lowest value (4 percent), while other income categories report 7 percent or higher. [72]
Some publicized diets, often referred to as fad diets, make exaggerated claims of fast weight loss or other health advantages, such as longer life or detoxification without clinical evidence; many fad diets are based on highly restrictive or unusual food choices. [73] [74] [75] Celebrity endorsements (including celebrity doctors) are frequently associated with such diets, and the individuals who develop and promote these programs often profit considerably. [28] : 11–12 [76]
Consumers are generally aware of the elements of a healthy diet, but find nutrition labels and diet advice in popular media confusing. [77]
Vending machines are criticized for being avenues of entry into schools for junk food promoters, but there is little in the way of regulation and it is difficult for most people to properly analyze the real merits of a company referring to itself as "healthy." The Committee of Advertising Practice in the United Kingdom launched a proposal to limit media advertising for food and soft drink products high in fat, salt, or sugar. [78] The British Heart Foundation released its own government-funded advertisements, labeled "Food4Thought", which were targeted at children and adults to discourage unhealthy habits of consuming junk food. [79]
From a psychological and cultural perspective, a healthier diet may be difficult to achieve for people with poor eating habits. [80] This may be due to tastes acquired in childhood and preferences for sugary, salty, and fatty foods. [81] In 2018, the UK chief medical officer recommended that sugar and salt be taxed to discourage consumption. [82] The UK government 2020 Obesity Strategy encourages healthier choices by restricting point-of-sale promotions of less-healthy foods and drinks. [83]
The effectiveness of population-level health interventions has included food pricing strategies, mass media campaigns and worksite wellness programs. [84] One peso per liter of sugar-sweetened beverages (SSB) price intervention implemented in Mexico produced a 12% reduction in SSB purchasing. [85] Mass media campaigns in Pakistan and the USA aimed at increasing vegetable and fruit consumption found positive changes in dietary behavior. [85] Reviews of the effectiveness of worksite wellness interventions found evidence linking the programs to weight loss and increased fruit and vegetable consumption. [86]
Animals that are kept by humans also benefit from a healthy diet, but the requirements of such diets may be very different from the ideal human diet. [87]
Dieting is the practice of eating food in a regulated way to decrease, maintain, or increase body weight, or to prevent and treat diseases such as diabetes and obesity. As weight loss depends on calorie intake, different kinds of calorie-reduced diets, such as those emphasising particular macronutrients, have been shown to be no more effective than one another. As weight regain is common, diet success is best predicted by long-term adherence. Regardless, the outcome of a diet can vary widely depending on the individual.
In nutrition, biology, and chemistry, fat usually means any ester of fatty acids, or a mixture of such compounds, most commonly those that occur in living beings or in food.
A saturated fat is a type of fat in which the fatty acid chains have all single bonds. A fat known as a glyceride is made of two kinds of smaller molecules: a short glycerol backbone and fatty acids that each contain a long linear or branched chain of carbon (C) atoms. Along the chain, some carbon atoms are linked by single bonds (-C-C-) and others are linked by double bonds (-C=C-). A double bond along the carbon chain can react with a pair of hydrogen atoms to change into a single -C-C- bond, with each H atom now bonded to one of the two C atoms. Glyceride fats without any carbon chain double bonds are called saturated because they are "saturated with" hydrogen atoms, having no double bonds available to react with more hydrogen.
A fad diet is a diet that is popular, generally only for a short time, similar to fads in fashion, without being a standard scientific dietary recommendation, and often making unreasonable claims for fast weight loss or health improvements; as such it is often considered a type of pseudoscientific diet. Fad diets are usually not supported by clinical research and their health recommendations are not peer-reviewed, thus they often make unsubstantiated statements about health and disease.
Low-carbohydrate diets restrict carbohydrate consumption relative to the average diet. Foods high in carbohydrates are limited, and replaced with foods containing a higher percentage of fat and protein, as well as low carbohydrate foods.
The Mediterranean diet is a diet inspired by the eating habits and traditional food typical of southern Spain, southern Italy, and Crete, and formulated in the early 1960s. It is distinct from Mediterranean cuisine, which covers the actual cuisines of the Mediterranean countries. While inspired by a specific time and place, the "Mediterranean diet" was later refined based on the results of multiple scientific studies.
In nutrition, diet is the sum of food consumed by a person or other organism. The word diet often implies the use of specific intake of nutrition for health or weight-management reasons. Although humans are omnivores, each culture and each person holds some food preferences or some food taboos. This may be due to personal tastes or ethical reasons. Individual dietary choices may be more or less healthy.
A plant-based diet is a diet consisting mostly or entirely of plant-based foods. Plant-based diets encompass a wide range of dietary patterns that contain low amounts of animal products and high amounts of fiber-rich plant products such as vegetables, fruits, whole grains, legumes, nuts and seeds. They do not need to be vegan or vegetarian but are defined in terms of low frequency of animal food consumption.
Calorie restriction is a dietary regimen that reduces the energy intake from foods and beverages without incurring malnutrition. The possible effect of calorie restriction on body weight management, longevity, and aging-associated diseases has been an active area of research.
Nutritional genomics, also known as nutrigenomics, is a science studying the relationship between human genome, human nutrition and health. People in the field work toward developing an understanding of how the whole body responds to a food via systems biology, as well as single gene/single food compound relationships. Nutritional genomics or Nutrigenomics is the relation between food and inherited genes, it was first expressed in 2001.
A whole grain is a grain of any cereal and pseudocereal that contains the endosperm, germ, and bran, in contrast to refined grains, which retain only the endosperm.
A diabetic diet is a diet that is used by people with diabetes mellitus or high blood sugar to minimize symptoms and dangerous complications of long-term elevations in blood sugar.
The European Prospective Investigation into Cancer and Nutrition (EPIC) study is a Europe-wide prospective cohort study of the relationships between diet and cancer, as well as other chronic diseases, such as cardiovascular disease. With over half a million participants, it is the largest study of diet and disease to be undertaken.
The Dietary Approaches to Stop Hypertension or the DASH diet is a diet to control hypertension promoted by the U.S.-based National Heart, Lung, and Blood Institute, part of the National Institutes of Health (NIH), an agency of the United States Department of Health and Human Services. The DASH diet is rich in fruits, vegetables, whole grains, and low-fat dairy foods. It includes meat, fish, poultry, nuts, and beans, and is limited in sugar-sweetened foods and beverages, red meat, and added fats. In addition to its effect on blood pressure, it is designed to be a well-balanced approach to eating for the general public. DASH is recommended by the United States Department of Agriculture (USDA) as a healthy eating plan. The DASH diet is one of three healthy diets recommended in the 2015–20 U.S. Dietary Guidelines, which also include the Mediterranean diet and a vegetarian diet. The American Heart Association (AHA) considers the DASH diet "specific and well-documented across age, sex and ethnically diverse groups."
The Western pattern diet is a modern dietary pattern that is generally characterized by high intakes of pre-packaged foods, refined grains, red meat, processed meat, high-sugar drinks, candy and sweets, fried foods, industrially produced animal products, butter and other high-fat dairy products, eggs, potatoes, corn, and low intakes of fruits, vegetables, whole grains, pasture-raised animal products, fish, nuts, and seeds.
The Dietary Guidelines for Americans (DGA) provide nutritional advice for Americans who are healthy or who are at risk for chronic disease but do not currently have chronic disease. The Guidelines are published every five years by the US Department of Agriculture, together with the US Department of Health and Human Services. Notably, the most recent ninth edition for 2020–25 includes dietary guidelines for children from birth to 23 months. In addition to the Dietary Guidelines per se, there are additional tools for assessing diet and nutrition, including the Healthy Eating Index (HEI), which can be used to assess the quality of a given selection of foods in the context of the Dietary Guidelines. Also provided are additional explanations regarding customization of the Guidelines to individual eating preferences, application of the Guidelines during pregnancy and infancy, the USDA Nutrition Evidence Systematic Review, information about the Nutrition Communicators Network and the MyPlate initiative, information from the National Academies about redesigning the process by which the Dietary Guidelines for Americans are created, and information about dietary guidelines from other nations.
Canadian health claims by Health Canada, the department of the Government of Canada responsible for national health, has allowed five scientifically verified disease risk reduction claims to be used on food labels and on food advertising. Other countries, including the United States and Great Britain, have approved similar health claims on food labels.
Weight management refers to behaviors, techniques, and physiological processes that contribute to a person's ability to attain and maintain a healthy weight. Most weight management techniques encompass long-term lifestyle strategies that promote healthy eating and daily physical activity. Moreover, weight management involves developing meaningful ways to track weight over time and to identify ideal body weights for different individuals.
MyPlate is the current nutrition guide published by the United States Department of Agriculture's Center for Nutrition Policy and Promotion, and serves as a recommendation based on the Dietary Guidelines for Americans. It replaced the USDA's MyPyramid guide on June 2, 2011, ending 19 years of USDA food pyramid diagrams. MyPlate is displayed on food packaging and used in nutrition education in the United States. The graphic depicts a place setting with a plate and glass divided into five food groups that are recommended parts of a healthy diet. This dietary recommendation combines an organized amount of fruits, vegetables, grains, protein, and dairy. It is designed as a guideline for Americans to base their plate around in order to make educated food choices. ChooseMyPlate.gov shows individuals the variety of these 5 subgroups based on their activity levels and personal characteristics.
Soul food is a kind of African American cuisine that encompasses a variety of fried, roasted, and boiled food dishes consisting of chicken and pork meats, sweet potatoes, corn, leafy greens and other vegetables. Soul food has long been embedded in African American culture, but pushes towards healthy eating habits, for both physical and mental health, have adapted soul food cuisine to fit within health trends. This article will describe modifications of traditional soul food within health trends, including soul food with low carb, soul food with low sugar, soul food with low fat, soul food for vegan and soul food in gluten-free.
Similar proteins to the gliadin found in wheat exist as secalin in rye, hordein in barley, and avenins in oats and are collectively referred to as "gluten." Derivatives of these grains such as triticale and malt and other ancient wheat varieties such as spelt and kamut also contain gluten. The gluten found in all of these grains has been identified as the component capable of triggering the immune-mediated disorder, coeliac disease.
The only treatment for CD, dermatitis herpetiformis (DH) and gluten ataxia is lifelong adherence to a GFD.
For both wheat allergy and coeliac disease the dietary avoidance of wheat and other gluten-containing cereals is the only effective treatment.
A recently proposed approach to NCGS diagnosis is an objective improvement of gastrointestinal symptoms and extra-intestinal manifestations assessed through a rating scale before and after GFD. Although a standardized symptom rating scale is not yet applied worldwide, a recent study indicated that a decrease of the global symptom score higher than 50% after GFD can be regarded as confirmatory of NCGS (Table 1) [53]. (…) After the confirmation of NCGS diagnosis, according to the previously mentioned work-up, patients are advized to start with a GFD [49].