Fresh vegetables are important components of a healthy diet.

A healthy diet is one that helps maintain or improve health. It is important for the prevention of many chronic health risks such as: obesity, heart disease, diabetes, and cancer.^[1]

A healthy diet involves consuming appropriate amounts of all nutrients, and an adequate amount of water. Nutrients can be obtained from many different foods, so there are a wide variety of diets that may be considered healthy diets. A healthy diet needs to have a balance of macronutrients / energy ( fats, proteins, and carbohydrates ) and micronutrients to meet the needs for human nutrition without inducing toxicity from excessive amounts.

[edit] 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. Evidence supports the consumption of polyunsaturated fats instead of saturated fats as a measure of decreasing coronary heart disease.^[2]

[edit] World Health Organization

The World Health Organization (WHO) makes the following 5 recommendations with respect to both populations and individuals:^[3]

• 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
• Limit the intake of simple sugar
• Limit salt / sodium consumption from all sources and ensure that salt is iodized

Other recommendations include:

• Sufficient essential amino acids ("complete protein") to provide cellular replenishment and transport proteins. All essential amino acids are present in animals. A select few plants (such as soy and hemp) give all the essential acids. A combination of other plants may also provide all essential amino acids. Fruits such as avocado and pumpkin seeds also have all the essential amino acids.^[4][5]
• Essential micronutrients such as 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).

[edit] American Heart Association

The American Heart Association recommends a diet rich in fruits, vegetables, and healthful fatty acids and that limit saturated fat.^[6]

[edit] Diets against 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 diets or the more specific DASH diet), or people who are overweight or obese (in weight control diets). However, some of them may have more or less evidence for beneficial effects in normal people as well.

[edit] Diets against hypertension

A low sodium diet is beneficial for people with high blood pressure. A Cochrane review published in 2008 concluded that a long term (more than 4 weeks) low sodium diet in Caucasians has a useful effect to reduce blood pressure, both in people with hypertension and in people with normal blood pressure.^[7]

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,^[8] 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".

Also, evidence shows that the Mediterranean diet improves cardiovascular outcomes.^[9]

[edit] Weight control diets

Weight control diets aim to 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.

Diets to promote weight loss are generally divided into four categories: low-fat, low-carbohydrate, low-calorie, and very low calorie.^[10] A meta-analysis 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.^[10] At two years, all calorie-reduced diet types cause equal weight loss irrespective of the macronutrients emphasized.^[11]

[edit] Diets to prevent cancer

A comprehensive worldwide report, Food, Nutrition, Physical Activity and the Prevention of Cancer: a Global Perspective, compiled by World Cancer Research Fund and American Institute for Cancer Research, 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 meat, alcoholic drinks and salt and avoiding sugary drinks, processed meat and mouldy cereals (grains) or pulses (legumes).

[edit] Unhealthy diets

An unhealthy diet is a major risk factor for a number of chronic diseases including: high blood pressure, diabetes, abnormal blood lipids, overweight/obesity, cardiovascular diseases, and cancer.^[12]

The WHO estimates that 2.7 million deaths are attributable to a diet low in fruit and vegetable every year.^[12] Globally it is estimated to cause about 19% of gastrointestinal cancer, 31% of ischaemic heart disease, and 11% of strokes,^[1] thus making it one of the leading preventable causes of death worldwide.^[13]

[edit] Food additive controversy

Based on information from the Ministries of Health of the United States, France, UK, Norway, Sweden, Denmark, Russia & Italy, they build a list of food additives that are not healthy ^[14]. On this long list we can see which food additives, such as artificial sweeteners, colorants, preserving agents, and flavorings may cause health problems such as increasing the risk of cancer or ADHD.^[15]

[edit] Fad diets

Fad diet usually refer to idiosyncratic diets and eating patterns. They are diets that claim to promote weight loss or treat obesity by mechanisms other than calorie restriction.^[16]

[edit] Public health

Fears of high cholesterol were frequently voiced up until the mid-1990s. However, more recent research has shown that the distinction between high- and low-density lipoprotein ('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^{[citation needed]}, 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^{[citation needed]}.

Media coverage of mass-produced, processed, "snack" or "sweet" products directly marketed at children has worked to undermine policy efforts to improve eating habits^{[citation needed]}.

Particularly within the last five years government agencies^[where?] have attempted to combat the amount and method of media coverage lavished upon "junk" foods^{[citation needed]}. 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^{[citation needed]}. Vending machines in particular have come under fire as being avenues of entry into schools for junk food 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's to advertise its products, as the majority of the foods that were seen have low nutrient values were aimed at children under the guise of the "Happy Meal"^{[citation needed]}. The British Heart 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.

[edit] Cultural and psychological factors

From a psychological perspective, a new healthy diet may be difficult to achieve for a person with poor eating habits. This may be due to tastes acquired in early adolescence and preferences for fatty foods. It may be easier for such a person to transition to a healthy diet if treats such as chocolate 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.^{[citation needed]} 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 anorexia or bulimia 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.^{[citation needed]}

While plants, vegetables, and fruits are known to help reduce the incidence of chronic disease,^{[citation needed]} the benefits on health posed by plant-based foods, as well as the percentage of which a diet needs to be plant based in order to have health benefits is unknown. Nevertheless, plant-based food diets in society and between nutritionist circles are linked to health and longevity, as well as contributing to lowering cholesterol, weight loss, and in some cases, stress reduction.^{[citation needed]}

[edit] See also

• Diet and cancer
• Diet and heart disease
• Food Balance Wheel
• Health food
• Center for Nutrition Policy and Promotion
• Health promotion
• List of diets
• Nutrigenomics
• Nutritional genomics
• Standard American Diet
• Raw foodism
• CRON-diet a diet intended to increase lifespan by about 30%
• Nutritional gatekeeper
• Online weight loss plans

[edit] References

[edit] External links

• Diet, Nutrition and the prevention of chronic diseases, by a Joint WHO/FAO 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.
• Healthy Diet - NHS Choices

• Healthy Diet