A
healthy diet is one that helps maintain or improve general
healthHealth is the level of functional or metabolic efficiency of a living being. In humans, it is the general condition of a person's mind, body and spirit, usually meaning to be free from illness, injury or pain...
. It is important for lowering many chronic health risks, such as
obesityObesity is a medical condition in which excess body fat has accumulated to the extent that it may have an adverse effect on health, leading to reduced life expectancy and/or increased health problems...
,
heart diseaseHeart disease, cardiac disease or cardiopathy is an umbrella term for a variety of diseases affecting the heart. , it is the leading cause of death in the United States, England, Canada and Wales, accounting for 25.4% of the total deaths in the United States.-Types:-Coronary heart disease:Coronary...
, diabetes,
hypertensionHypertension or high blood pressure is a cardiac chronic medical condition in which the systemic arterial blood pressure is elevated. What that means is that the heart is having to work harder than it should to pump the blood around the body. Blood pressure involves two measurements, systolic and...
and
cancerCancer , known medically as a malignant neoplasm, is a large group of different diseases, all involving unregulated cell growth. In cancer, cells divide and grow uncontrollably, forming malignant tumors, and invade nearby parts of the body. The cancer may also spread to more distant parts of the...
. A healthy diet involves consuming appropriate amounts of all
essential nutrientAn essential nutrient is a nutrient required for normal body functioning that either cannot be synthesized by the body at all, or cannot be synthesized in amounts adequate for good health , and thus must be obtained from a dietary source...
s and an adequate amount of
waterWater is a chemical substance with the chemical formula H2O. A water molecule contains one oxygen and two hydrogen atoms connected by covalent bonds. Water is a liquid at ambient conditions, but it often co-exists on Earth with its solid state, ice, and gaseous state . Water also exists in a...
. Nutrients can be obtained from many different foods, so there are numerous diets that may be considered healthy. A healthy diet needs to have a balance of macronutrients (fats, proteins, and carbohydrates), calories to support energy needs, and micronutrients to meet the needs for
human nutritionHuman nutrition is the provision to humans to obtain the materials necessary to support life. In general, humans can survive for two to eight weeks without food, depending on stored body fat and muscle mass. Survival without water is usually limited to three or four days...
without inducing toxicity or excessive weight gain from consuming excessive amounts.
Dietary recommendations
There are a number of diets and recommendations by numerous medical and governmental institutions that are designed to promote certain aspects of health.
World Health Organization
The
World Health OrganizationThe World Health Organization is a specialized agency of the United Nations that acts as a coordinating authority on international public health. Established on 7 April 1948, with headquarters in Geneva, Switzerland, the agency inherited the mandate and resources of its predecessor, the Health...
(WHO) makes the following 5 recommendations with respect to both populations and individuals:
- Achieve an energy balance and a healthy weight
- Limit energy intake from total fats and shift fat consumption away from saturated fats to unsaturated fats and towards the elimination of trans-fatty acids
- Increase consumption of fruits and vegetables, legumes, whole grains and nuts
A nut is a hard-shelled fruit of some plants having an indehiscent seed. While a wide variety of dried seeds and fruits are called nuts in English, only a certain number of them are considered by biologists to be true nuts...
- Limit the intake of simple sugar
Sugar is a class of edible crystalline carbohydrates, mainly sucrose, lactose, and fructose, characterized by a sweet flavor.Sucrose in its refined form primarily comes from sugar cane and sugar beet...
-- A 2003 report recommends less than 10% simple sugars
- Limit salt
In chemistry, salts are ionic compounds that result from the neutralization reaction of an acid and a base. They are composed of cations and anions so that the product is electrically neutral...
/ sodiumSodium is a chemical element with the symbol Na and atomic number 11. It is a soft, silvery-white, highly reactive metal and is a member of the alkali metals; its only stable isotope is 23Na. It is an abundant element that exists in numerous minerals, most commonly as sodium chloride...
consumption from all sources and ensure that salt is iodizedIodised salt is table salt mixed with a minute amount of various iodine-containing salts. The ingestion of iodide prevents iodine deficiency. Worldwide, iodine deficiency affects about two billion people and is the leading preventable cause of mental retardation. It also causes thyroid gland...
Other recommendations include:
- Sufficient essential amino acids to provide cellular replenishment and transport proteins. All essential amino acids are present only in animals. Many plants such as quinoa, soy, and hemp also provide almost all the essential acids but are always lacking in one or more essential amino acid. Those who omit meat products from their diets may still easily obtain all the essential amino acid in their diets by consuming adequate amounts of plant products and grain products, which combine to provide complete proteins to the diet. Fruits such as avocado and pumpkin seeds also have almost all of the essential amino acids.
- Essential micronutrients such as vitamins and certain minerals.
- Avoiding directly poisonous (e.g. heavy metals) and carcinogenic (e.g. benzene
Benzene is an organic chemical compound. It is composed of 6 carbon atoms in a ring, with 1 hydrogen atom attached to each carbon atom, with the molecular formula C6H6....
) substances;
- Avoiding foods contaminated by human pathogens (e.g. E. coli, tapeworm eggs).
American Heart Association
The American Heart Association recommends a diet rich in fruits, vegetables, healthful fatty acids and limited saturated fat.
For specific conditions
In addition to dietary recommendations for the general population, there are many specific diets that have primarily been developed to promote better health in specific population groups, such as people with high blood pressure (as in
low sodium dietA low sodium diet is a diet that includes no more than 1,500 to 2,400 mgs of sodium per day. People who follow a vigorous or moderate exercise schedule are usually advised to limit their sodium intake to 3,000 mg per day and those with moderate to severe heart failure are usually advised to...
s or the more specific DASH diet), or people who are
overweightOverweight is generally defined as having more body fat than is optimally healthy. Being overweight is a common condition, especially where food supplies are plentiful and lifestyles are sedentary...
or
obeseObesity is a medical condition in which excess body fat has accumulated to the extent that it may have an adverse effect on health, leading to reduced life expectancy and/or increased health problems...
(in
weight control dietDieting is the practice of eating food in a regulated fashion to achieve or maintain a controlled weight. In most cases dieting is used in combination with physical exercise to lose weight in those who are overweight or obese. Some athletes, however, follow a diet to gain weight...
s). However, some of them may have more or less evidence for beneficial effects in normal people as well.
Hypertension
A
low sodium dietA low sodium diet is a diet that includes no more than 1,500 to 2,400 mgs of sodium per day. People who follow a vigorous or moderate exercise schedule are usually advised to limit their sodium intake to 3,000 mg per day and those with moderate to severe heart failure are usually advised to...
is beneficial for people with
high blood pressureHypertension or high blood pressure is a cardiac chronic medical condition in which the systemic arterial blood pressure is elevated. What that means is that the heart is having to work harder than it should to pump the blood around the body. Blood pressure involves two measurements, systolic and...
. A Cochrane review published in 2008 concluded that a long term (more than 4 weeks) low sodium diet in
CaucasiansThe term Caucasian race has been used to denote the general physical type of some or all of the populations of Europe, North Africa, the Horn of Africa, Western Asia , Central Asia and South Asia...
has a useful effect to reduce blood pressure, both in people with
hypertensionHypertension or high blood pressure is a cardiac chronic medical condition in which the systemic arterial blood pressure is elevated. What that means is that the heart is having to work harder than it should to pump the blood around the body. Blood pressure involves two measurements, systolic and...
and in people with normal blood pressure.
The DASH diet (Dietary Approaches to Stop Hypertension) is a
dietDieting is the practice of eating food in a regulated fashion to achieve or maintain a controlled weight. In most cases dieting is used in combination with physical exercise to lose weight in those who are overweight or obese. Some athletes, however, follow a diet to gain weight...
promoted by the
National Heart, Lung, and Blood InstituteThe National Heart, Lung, and Blood Institute is a division of the National Institutes of Health, located in Bethesda, Maryland...
(part of the NIH, a United States government organization) to control
hypertensionHypertension or high blood pressure is a cardiac chronic medical condition in which the systemic arterial blood pressure is elevated. What that means is that the heart is having to work harder than it should to pump the blood around the body. Blood pressure involves two measurements, systolic and...
. A major feature of the plan is limiting intake of
sodiumSodium is a chemical element with the symbol Na and atomic number 11. It is a soft, silvery-white, highly reactive metal and is a member of the alkali metals; its only stable isotope is 23Na. It is an abundant element that exists in numerous minerals, most commonly as sodium chloride...
, and it 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". Evidence shows that the
Mediterranean dietThe Mediterranean diet is a modern nutritional recommendation inspired by the traditional dietary patterns of southern Italy, Crete and much of the rest of Greece in the 1960s....
improves cardiovascular outcomes.
Obesity
Weight control dietsDieting is the practice of eating food in a regulated fashion to achieve or maintain a controlled weight. In most cases dieting is used in combination with physical exercise to lose weight in those who are overweight or obese. Some athletes, however, follow a diet to gain weight...
aim to maintain a controlled weight. In most cases dieting is used in combination with
physical exercisePhysical exercise is any bodily activity that enhances or maintains physical fitness and overall health and wellness. It is performed for various reasons including strengthening muscles and the cardiovascular system, honing athletic skills, weight loss or maintenance, as well as for the purpose of...
to
lose weightWeight loss, in the context of medicine, health or physical fitness, is a reduction of the total body mass, due to a mean loss of fluid, body fat or adipose tissue and/or lean mass, namely bone mineral deposits, muscle, tendon and other connective tissue...
in those who are
overweightOverweight is generally defined as having more body fat than is optimally healthy. Being overweight is a common condition, especially where food supplies are plentiful and lifestyles are sedentary...
or obese.
Diets to promote
weight lossWeight loss, in the context of medicine, health or physical fitness, is a reduction of the total body mass, due to a mean loss of fluid, body fat or adipose tissue and/or lean mass, namely bone mineral deposits, muscle, tendon and other connective tissue...
are generally divided into four categories:
low-fatAccording to the USDA, a low-fat diet as the name implies is a diet that consists of little fat, especially saturated fat and cholesterol, which are thought to lead to increased blood cholesterol levels and heart attack...
,
low-carbohydrateLow-carbohydrate diets or low-carb diets are dietary programs that restrict carbohydrate consumption usually for weight control or for the treatment of obesity. Foods high in digestible carbohydrates are limited or replaced with foods containing a higher percentage of proteins and fats...
,
low-calorieCaloric restriction , or calorie restriction, is a dietary regimen that restricts calorie intake, where the baseline for the restriction varies, usually being the previous, unrestricted, intake of the subjects...
, and
very low calorieVery low calorie diet is a diet with very or extremely low daily food energy consumption. It is defined as a diet of per day or less. VLCDs are formulated, nutritionally complete, liquid meals containing 800 kilocalories or less per day. VLCDs also contain the recommended daily requirements for...
. A
meta-analysisIn statistics, a meta-analysis combines the results of several studies that address a set of related research hypotheses. In its simplest form, this is normally by identification of a common measure of effect size, for which a weighted average might be the output of a meta-analyses. Here the...
of six randomized controlled trials found no difference between the main diet types (low calorie, low carbohydrate, and low fat), with a 2–4 kilogram weight loss in all studies. At two years, all calorie-reduced diet types cause equal weight loss irrespective of the macronutrients emphasized.
Cancer prevention
A comprehensive worldwide report,
Food, Nutrition, Physical Activity and the Prevention of Cancer: a Global PerspectiveFood, Nutrition, Physical Activity and the Prevention of Cancer: a Global Perspective, also known as the Expert Report, was an expert report published by the World Cancer Research Fund global network in 2007....
, compiled by
World Cancer Research FundWorld Cancer Research Fund International is a not-for-profit association, established by royal decree in Belgium, with headquarters in London, UK...
and
American Institute for Cancer ResearchThe American Institute for Cancer Research is a large American cancer research organization associated with the World Cancer Research Fund umbrella organization.Its stated mission is:...
, reports that there is significant relation between lifestyle (including food consumption) and cancer prevention. The same report recommends eating mostly foods of plant origin and aiming to meet nutritional needs through diet alone, while limiting consumption of energy-dense foods,
red meatRed meat in traditional culinary terminology is meat which is red when raw and not white when cooked. In the nutritional sciences, red meat includes all mammal meat. Red meat includes the meat of most adult mammals and some fowl ....
, alcoholic drinks and
saltIn chemistry, salts are ionic compounds that result from the neutralization reaction of an acid and a base. They are composed of cations and anions so that the product is electrically neutral...
and avoiding sugary drinks, and processed meat.
Unhealthy diets
An unhealthy diet is a major risk factor for a number of chronic diseases including: high blood pressure, diabetes, abnormal blood lipids,
overweightOverweight is generally defined as having more body fat than is optimally healthy. Being overweight is a common condition, especially where food supplies are plentiful and lifestyles are sedentary...
/
obesityObesity is a medical condition in which excess body fat has accumulated to the extent that it may have an adverse effect on health, leading to reduced life expectancy and/or increased health problems...
, cardiovascular diseases, and
cancerCancer , known medically as a malignant neoplasm, is a large group of different diseases, all involving unregulated cell growth. In cancer, cells divide and grow uncontrollably, forming malignant tumors, and invade nearby parts of the body. The cancer may also spread to more distant parts of the...
.
The WHO estimates that 2.7 million deaths are attributable to a diet low in fruit and vegetable every year. Globally it is estimated to cause about 19% of
gastrointestinal cancerGastrointestinal cancer refers to malignant conditions of the gastrointestinal tract, including the esophagus, stomach, biliary system, pancreas, bowels, and anus. The symptoms relate to the organ affected, and can include obstruction , abnormal bleeding, or other associated problems...
, 31% of
ischaemic heart diseaseIschaemic or ischemic heart disease , or myocardial ischaemia, is a disease characterized by ischaemia of the heart muscle, usually due to coronary artery disease...
, and 11% of strokes, thus making it one of the leading
preventable causes of deathThe World Health Organization has traditionally classified death according to the primary type of disease or injury. However, causes of death may also be classified in terms of preventable risk factors—such as smoking, unhealthy diet, and sexual behavior—which contribute to a number of different...
worldwide.
Fad diets
FadIn biochemistry, flavin adenine dinucleotide is a redox cofactor involved in several important reactions in metabolism. FAD can exist in two different redox states, which it converts between by accepting or donating electrons. The molecule consists of a riboflavin moiety bound to the phosphate...
diet usually refer to idiosyncratic diets and eating patterns. They are diets that claim to promote
weight lossWeight loss, in the context of medicine, health or physical fitness, is a reduction of the total body mass, due to a mean loss of fluid, body fat or adipose tissue and/or lean mass, namely bone mineral deposits, muscle, tendon and other connective tissue...
or treat
obesityObesity is a medical condition in which excess body fat has accumulated to the extent that it may have an adverse effect on health, leading to reduced life expectancy and/or increased health problems...
by various mechanisms.
Public health
Fears of high
cholesterolCholesterol is a complex isoprenoid. Specifically, it is a waxy steroid of fat that is produced in the liver or intestines. It is used to produce hormones and cell membranes and is transported in the blood plasma of all mammals. It is an essential structural component of mammalian cell membranes...
were frequently voiced up until the mid-1990s. However, more recent research has shown that the distinction between high- and low-density
lipoproteinA lipoprotein is a biochemical assembly that contains both proteins and lipids water-bound to the proteins. Many enzymes, transporters, structural proteins, antigens, adhesins, and toxins are lipoproteins...
('good' and 'bad' cholesterol, respectively) must be addressed when speaking of the potential ill effects of cholesterol. Different types of dietary fat have different effects on blood levels of cholesterol. For example, polyunsaturated fats tend to decrease both types of cholesterol; monounsaturated fats tend to lower LDL and raise HDL; saturated fats tend to either raise HDL, or raise both HDL and LDL; and trans fat tend to raise LDL and lower HDL. Dietary cholesterol itself is only found in animal products such as meat, eggs, and dairy, but studies have shown that even large amounts of dietary cholesterol only have negligible effects on blood cholesterol.
Particularly within the last five years government agencies have attempted to combat the amount and method of media coverage lavished upon "junk" foods. Governments also put pressure on businesses to promote healthful food options, consider limiting the availability of junk food in state-run schools, and tax foods that are high in fat.
Vending machineA vending machine is a machine which dispenses items such as snacks, beverages, alcohol, cigarettes, lottery tickets, consumer products and even gold and gems to customers automatically, after the customer inserts currency or credit into the machine....
s in particular have come under fire as being avenues of entry into schools for
junk foodJunk food is an informal term applied to some foods that are perceived to have little or no nutritional value ; to products with nutritional value, but which also have ingredients considered unhealthy when regularly eaten; or to those considered unhealthy to consume at all...
promoters. However, 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." Recently, the United Kingdom removed the rights for
McDonald'sMcDonald's Corporation is the world's largest chain of hamburger fast food restaurants, serving around 64 million customers daily in 119 countries. Headquartered in the United States, the company began in 1940 as a barbecue restaurant operated by the eponymous Richard and Maurice McDonald; in 1948...
to advertise its products, as the majority of the foods that were seen have low nutrient values and high fat counts were aimed at children under the guise of the "Happy Meal". The
British Heart FoundationThe British Heart Foundation is a charity organisation in Britain that funds research, education, care and awareness campaigns aimed to prevent heart diseases in humans.-Foundation:...
released its own government-funded advertisements, labeled "
Food4Thought", which were targeted at children and adults displaying the gory nature of how fast food is generally constituted.
Cultural and psychological factors
From a psychological and cultural perspective, a healthier diet may be difficult to achieve for people with poor eating habits. This may be due to tastes acquired in early adolescence and preferences for sugary and fatty foods. It may be easier for such a person to transition to a healthy diet if treats such as
chocolateChocolate is a raw or processed food produced from the seed of the tropical Theobroma cacao tree. Cacao has been cultivated for at least three millennia in Mexico, Central and South America. Its earliest documented use is around 1100 BC...
are allowed; sweets may act as mood stabilizers, which could help reinforce correct nutrient intake.
It is known that the experiences we have in childhood relating to consumption of food affect our perspective on food consumption in later life. From this, we are able to determine ourselves our limits of how much we will eat, as well as foods we will not eat - which can develop into eating disorders, such as
anorexiaAnorexia nervosa is an eating disorder characterized by refusal to maintain a healthy body weight and an obsessive fear of gaining weight. Although commonly called "anorexia", that term on its own denotes any symptomatic loss of appetite and is not strictly accurate...
or
bulimiaBulimia nervosa is an eating disorder characterized by binge eating and purging or consuming a large amount of food in a short amount of time, followed by an attempt to rid oneself of the food consumed, usually by purging and/or by laxative, diuretics or excessive exercise. Bulimia nervosa is...
This is also true with how we perceive the sizes of the meals or amounts of food we consume daily; people have different interpretations of small and large meals based on upbringing.
External links
- Diet, Nutrition and the prevention of chronic diseases, by a Joint WHO
Who may refer to:* Who , an English-language pronoun* who , a Unix command* Who?, one of the Five Ws in journalism- Art and entertainment :* Who? , a 1958 novel by Algis Budrys...
/FAOFão is a town in Esposende Municipality in Portugal....
Expert consultation (2003)
- Foods for Healthy Diet - A searchable collection of nutritional data on thousands of foods for healthy diet. Based on the U.S. Department of Agriculture database for standard reference SR22.