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Patient education: Diet and health (Beyond the Basics)

Patient education: Diet and health (Beyond the Basics)
Author:
Graham A Colditz, MD, DrPH
Section Editor:
David Seres, MD
Deputy Editor:
Jane Givens, MD, MSCE
Literature review current through: Nov 2022. | This topic last updated: Oct 13, 2022.

IMPACT OF A HEALTHY DIET — A healthy diet can improve your health and lower the risk of problems like heart disease, diabetes, high blood pressure, and some types of cancer. It can also help you maintain a healthy body weight and improve overall quality of life.

This article discusses dietary patterns and components, as well as guidance on how to make healthy choices.

Dietary changes to promote weight loss are discussed separately. (See "Patient education: Losing weight (Beyond the Basics)", section on 'Changing your eating habits'.)

What kind of diet is best? — There is no one specific diet that experts recommend everyone follow. People choose what foods to eat for many different reasons, including personal preference, cultural or religious influences, and nutritional content. Cost and availability also play a role.

In general, based on many different studies over time, experts recommend a diet that:

Includes lots of vegetables, fruits, beans, nuts, and whole grains

Limits red and processed meats, unhealthy fats, sugar, salt, and alcohol

Making healthy diet choices can reduce your risk of developing certain health problems and help you live longer.

How many calories do I need? — Calories give your body energy. Your health can be affected not only by the number of calories you consume but also by the foods they come from.

Most dietary recommendations are based on the assumption that the average adult consumes about 2000 calories per day. However, the ideal number of calories for an individual depends on their age, sex, weight, height, and activity level. Consuming too many calories leads to weight gain and increases the risk of health problems.

Your health care provider or a dietitian (nutrition expert) can help you figure out about how many calories you should be getting each day. In addition to eating a healthy diet, getting plenty of physical activity is also important, not only for managing your weight but also for your overall health and well-being. (See "Patient education: Exercise (Beyond the Basics)".)

DIETARY PATTERNS — A dietary "pattern" means generally being in the habit of eating certain types of foods while limiting others. Some people need to follow a particular dietary pattern because of their individual health needs; for example, if you have high blood pressure, your health care provider might recommend a diet low in sodium (salt).

If you are trying to improve your overall health and lower your risk of disease, establishing a healthy dietary pattern can help. This does not have to mean being extremely restrictive or eating only healthy choices. It is more of a lifestyle choice to incorporate certain dietary components while limiting others. You can find which approaches work for you, and that can help you maintain and build on a healthy eating pattern over time.

Some dietary patterns have been found to have specific health benefits. Others may have benefits for some people, for example, those with specific health conditions.

Mediterranean diet — A Mediterranean diet is high in fruits, vegetables, beans, nuts, and seeds. It also includes olive oil as a source of healthy fat, and moderate amounts of fish, poultry, and dairy products, but little red meat. Studies have found that this type of diet lowers the risk of heart disease and stroke and helps control blood sugar in people with diabetes. It may also lower the risk of certain types of cancer.

DASH diet — The Dietary Approaches to Stop Hypertension (DASH) diet requires a person to eat four to five servings of fruit, four to five servings of vegetables, and two to three servings of low-fat dairy per day. All foods must contain less than 25 percent total fat per serving. It can help lower blood pressure, especially when the person also reduces their salt intake. The DASH diet may also lower the risk of other health problems, including colorectal cancer, heart disease, and gout (in males).

Plant-based diets — Plant-based diets focus on vegetables, fruits, grains, beans, and nuts and limit, or completely avoid, food from animals, such as meat and dairy. There are different types of plant-based diets, including:

Macrobiotic – This type of diet includes lots of vegetables, fruits, legumes, and seaweeds, as well as whole grains like brown rice. People who follow a macrobiotic diet might limit animal foods to white meat or fish once or twice a week.

Semi-vegetarian (sometimes called "flexitarian") – Some people choose to eat meat only occasionally, or avoid red meat but eat poultry and/or fish.

Lacto-ovovegetarian – This means a person eats milk and dairy products as well as eggs, but no meat.

Lactovegetarian – This means a person eats milk and dairy products, but not eggs or meat.

Vegan – This means avoiding all food products that come from animal sources, including eggs and milk products.

Plant-based diets may lower the risk of obesity, heart disease, high blood pressure, diabetes, and some cancers. While plant-based diets are generally healthy, as with other patterns, it's also important to limit things like processed foods, unhealthy fats, sugar, and salt. If you do not eat meat and/or other animal products, it is important to ensure you are getting enough nutrients overall. Vegans, in particular, have been found to be low in nutrients like calcium and vitamin B12. (See 'Vitamins and supplements' below.)

Low-fat diet — A low-fat diet involves limiting intake of calories from fat. This pattern may have some benefits when it comes to maintaining a lower weight, but overall it is likely no more effective than other approaches in helping people lose weight. In general, few, if any, other health benefits have been linked to low-fat diets.

When following a low-fat diet, it is important to focus on whole grains, legumes, fruits, and vegetables, with limited refined grains and sugar. Fats should be from healthy sources, such as fatty fish, nuts, olive oil, and canola oil. (See 'Healthy fats' below and 'Unhealthy fats' below.)

Low-cholesterol diet — Cholesterol is typically found in foods with a lot of saturated fat, like red meat, butter, and cheese. A low-cholesterol diet focuses on limiting the amount of cholesterol in the diet. Since high-cholesterol foods also generally are high in unhealthy fats (such as saturated fat), limiting the cholesterol in your diet can also help reduce the amount of unhealthy fats you consume. (See 'Unhealthy fats' below.)

Dietary patterns with limited evidence of health benefit — Other dietary patterns have limited evidence of health benefits for the general population. These include the low-carbohydrate diet (including the very low carbohydrate ketogenic or "keto" diet), organic diet, anti-inflammatory diet, and gluten-free diet. While some of these diets may have benefit in specific situations (for example, people with diagnosed celiac disease do benefit from eliminating gluten), and each approach may have some components that are likely to improve overall health, there is limited evidence to widely recommend any of them.

DIETARY COMPONENTS WITH HEALTH BENEFITS — While experts recommend focusing on establishing a healthy dietary pattern in order to maximize the benefits, it can also help to understand the different "components" or parts of a healthy diet. Some people may find it easier to start by making small changes in some of these areas.

The 2020 to 2025 Dietary Guidelines for Americans have recommendations for how much of a healthy diet should come from each of these components [1].

Fruits and vegetables — A number of studies have demonstrated important health benefits of eating fruits and vegetables.

Increased intake of fruits and vegetables is linked to a lower risk of premature death as well as heart disease and stroke.

High intake of fruits and vegetables may reduce the risk of developing cancer. Tomato and tomato-based foods may be beneficial at lowering the risk of prostate cancer, particularly advanced disease.

Experts recommend getting at least five servings of fruits and/or vegetables every day.

Whole grains — Whole-grain foods (like 100 percent whole-wheat bread, steel cut oats, and whole-grain pasta) are healthier choices than foods made with refined grains (like white bread and white rice). Regularly eating whole grains has been shown to help with weight control and to lower the risk of a range of conditions, including colorectal cancer, cardiovascular disease, and diabetes.

Fiber — Eating a diet that is high in fiber can decrease the risk of heart disease and colon cancer. Eating fiber also protects against type 2 diabetes, and eating soluble fiber (such as that found in vegetables, fruits, and especially legumes) may help control blood sugar in people who already have diabetes. (See "Patient education: High-fiber diet (Beyond the Basics)".)

The recommended amount of dietary fiber is about 14 grams per 1000 calories, which amounts to about 25 to 34 grams per day for most adults. Many breakfast cereals, fruits, and vegetables are excellent sources of dietary fiber. By reading the product information panel on the side of the package, it is possible to determine the number of grams of fiber per serving (figure 1). A list of the fiber content of a number of foods can be found in the table (table 1).

Dairy products — Consuming dairy products may lower the risk of colorectal cancer and possibly heart disease. Low-fat dairy is also an important part of the DASH diet. (See 'DASH diet' above.)

Experts recommend that most adults consume three cups of dairy products a day. Good options include low- or non-fat milk or non-fat plan (unsweetened) yogurt. Dairy products contain protein, calcium, vitamin D, and potassium.

Adequate calcium and vitamin D intake are important, particularly for females, to improve bone health. (See "Patient education: Calcium and vitamin D for bone health (Beyond the Basics)".)

Protein — Protein is important for keeping your muscles and bones strong. Healthy choices include lean poultry, fish, beans, seeds, nuts, and soy products. Eating plenty of nuts and fish may help lower the risk of heart disease. These foods also contain healthy fats. (See 'Healthy fats' below.)

Experts recommend that most adults get 5.5 ounces of protein-rich foods daily.

Healthy fats — There are different types of dietary fat; in terms of health benefits, the type of fat in the diet is more important than the overall amount. "Healthy" fats are monounsaturated or polyunsaturated fats. These are found in nuts, seeds, avocados, and nut butters, as well as olive, canola, and sesame oil. Eating foods with healthy fats, while avoiding or limiting foods with "unhealthy" fats, may reduce the risk of heart disease. (See 'Unhealthy fats' below.)

DIETARY COMPONENTS TO LIMIT OR AVOID — Some dietary components are associated with known health risks. Being aware of these so you can avoid or limit them (or replace them with healthier alternatives) can improve your overall health and help lower your risk of certain diseases.

Unhealthy fats — "Unhealthy" fats are saturated fats and trans fats. Saturated fats are found in animal products such as meats, egg yolks, butter, cheese and full-fat milk products. Trans fats, like partially hydrogenated oils, can be found in some fast foods and packaged foods like cookies or other baked goods. Though trans fats used to be common in many foods in the United States, they have largely been removed from foods since 2018. However, some foods can still include some trans fat, such as some fast foods and shortenings and oils with “hydrogenated oil” listed in the ingredients.

Replacing these fats with "healthy" fats can lower the risk of heart disease and improve your health. (See 'Healthy fats' above.)

Added sugars — Eating foods with a lot of added sugars, including sugar-sweetened beverages like fruit drinks, sugary sodas, and sports drinks, increases the risk of heart disease, diabetes, and high blood pressure. It also contributes to weight gain. While 100 percent fruit juice has natural sugars and some extra nutrients, it has around as many calories as sugary soda. Eating whole fruit instead is the best choice.

Red and processed meats — Eating a lot of red meat or processed meats (like sausage, hot dogs, and bacon) increases the risk of several health problems including heart disease, diabetes, and colorectal cancer.

Processed foods — Processed foods include pre-packaged items like snack foods, frozen meals, and instant soups. They are often high in refined grains, sugar, unhealthy fats, and salt, and low in other important nutrients. Eating a lot of processed foods may increase the risk of heart disease, diabetes, and cancer.

Alcohol — Not drinking alcohol is the overall healthiest choice. Regular drinking can increase the risk of cancer, liver disease, injuries, and other harms, and even small amounts of alcohol can increase the risk of some of these conditions. (See "Patient education: Alcohol use — when is drinking a problem? (Beyond the Basics)".)

TIPS TO HELP YOU EAT A HEALTHY DIET — If you want to improve your diet but are not sure where to start, your health care provider can help. They might also refer you to a dietitian (nutrition expert) who can help make specific recommendations. If it feels overwhelming to think about completely changing the way you eat, remember that even small changes can improve your health.

The following tips may help you increase your intake of fruits, vegetables, and whole grains:

Make fruits and vegetables part of every meal. Eat a variety of fruits and vegetables. Frozen or canned can be used when fresh isn't convenient, but look for options without added salt (sodium) or sugar.

Eat vegetables as snacks.

Have a bowl of fruit out all the time for household members to snack from.

Add fruit to your cereal.

Try to make sure at least half of all your grains are whole grains. Choose 100 percent whole-wheat bread, brown rice, and whole-grain cereal over refined grains like white bread, white rice, and sweetened cereals.

To cut down on unhealthy fats and consume more healthy fats instead:

Choose chicken, fish, and beans instead of red meat and cheese.

Cook with oils that contain polyunsaturated and monounsaturated fats, like corn, olive, and peanut oil.

Eat fewer prepared and processed foods and baked goods.

When eating at fast food restaurants, choose healthier items, like broiled chicken or salad.

To cut down on sugary drinks and alcohol:

Instead of drinks with alcohol, choose non-sweetened and non-alcoholic beverages, like water or flavored seltzer.

Avoid occasions centered around alcohol.

Avoid making sugary drinks and alcohol an essential part of family and other social gatherings.

VITAMINS AND SUPPLEMENTS — In general, people who are in good health and eat a healthy and varied diet do not need to take regular vitamin supplements. However, there are some exceptions to this, including:

People who eat a restricted diet – If you limit or restrict animal products, you may need to take a B12 vitamin. Your health care provider may also recommend calcium and/or vitamin D supplements if you do not get enough of these through your diet.

People who have had bariatric (weight loss) surgery – If you have had weight loss surgery, your health care provider will tell you if you need supplements. Supplements may be needed because surgery can affect your body's ability to absorb vitamins from the foods you eat.

People who are pregnant, planning to get pregnant – It’s recommended that people who are planning to get pregnant, or are pregnant, get 400 to 800 mcg of folic acid every day. This helps prevent serious birth defects called neural tube defects. Some foods, like whole grains, leafy-green vegetables, and fortified breakfast cereals, provide folic acid (often called folate), but most people need to take a supplement to get these recommended daily amounts. Folic acid is included in prenatal vitamins and most multi-vitamins.

People who are found to have a specific vitamin deficiency also need to take supplements. However, unless your health care provider has specifically recommended that you take a vitamin or other supplement, it's a good idea to be cautious about using these products. Their general health benefits are likely limited, and they can have some possible harms.

WHERE TO GET MORE INFORMATION — Your healthcare provider is the best source of information for questions and concerns related to your medical problem.

This article will be updated as needed on our web site (www.uptodate.com/patients). Related topics for patients, as well as selected articles written for healthcare professionals, are also available. Some of the most relevant are listed below.

Patient level information — UpToDate offers two types of patient education materials.

The Basics — The Basics patient education pieces answer the four or five key questions a patient might have about a given condition. These articles are best for patients who want a general overview and who prefer short, easy-to-read materials.

Patient education: Diet and health (The Basics)
Patient education: High-fiber diet (The Basics)
Patient education: Coronary artery bypass graft surgery (The Basics)
Patient education: Vitamin B12 deficiency and folate deficiency (The Basics)
Patient education: Coronary artery disease in women (The Basics)
Patient education: Vitamin supplements (The Basics)
Patient education: Can foods or supplements lower cholesterol? (The Basics)
Patient education: Vegetarian diet (The Basics)

Beyond the Basics — Beyond the Basics patient education pieces are longer, more sophisticated, and more detailed. These articles are best for patients who want in-depth information and are comfortable with some medical jargon.

Patient education: Losing weight (Beyond the Basics)
Patient education: High-fiber diet (Beyond the Basics)
Patient education: High cholesterol and lipids (Beyond the Basics)
Patient education: Calcium and vitamin D for bone health (Beyond the Basics)
Patient education: Starting solid foods during infancy (Beyond the Basics)
Patient education: Risks and benefits of alcohol (Beyond the Basics)

Professional level information — Professional level articles are designed to keep doctors and other health professionals up-to-date on the latest medical findings. These articles are thorough, long, and complex, and they contain multiple references to the research on which they are based. Professional level articles are best for people who are comfortable with a lot of medical terminology and who want to read the same materials their doctors are reading.

Diet in the treatment and prevention of hypertension
Dietary assessment in adults
Dietary fat
Fish oil: Physiologic effects and administration
Lipid management with diet or dietary supplements
Nutrition in pregnancy: Dietary requirements and supplements
Healthy diet in adults

The following organizations also provide reliable health information.

National Library of Medicine

(www.nlm.nih.gov/medlineplus/healthtopics.html)

Your Disease Risk at Washington University in St. Louis

(www.yourdiseaserisk.wustl.edu)

The Nutrition Source at Harvard School of Public Health

(www.hsph.harvard.edu/nutritionsource/)

Endocrine Society

(www.endocrine.org)

  1. United States Department of Agriculture. Dietary guidelines for Americans 2020-2025. Available at: https://www.dietaryguidelines.gov/sites/default/files/2020-12/Dietary_Guidelines_for_Americans_2020-2025.pdf (Accessed on May 20, 2021).
This generalized information is a limited summary of diagnosis, treatment, and/or medication information. It is not meant to be comprehensive and should be used as a tool to help the user understand and/or assess potential diagnostic and treatment options. It does NOT include all information about conditions, treatments, medications, side effects, or risks that may apply to a specific patient. It is not intended to be medical advice or a substitute for the medical advice, diagnosis, or treatment of a health care provider based on the health care provider's examination and assessment of a patient's specific and unique circumstances. Patients must speak with a health care provider for complete information about their health, medical questions, and treatment options, including any risks or benefits regarding use of medications. This information does not endorse any treatments or medications as safe, effective, or approved for treating a specific patient. UpToDate, Inc. and its affiliates disclaim any warranty or liability relating to this information or the use thereof. The use of this information is governed by the Terms of Use, available at https://www.wolterskluwer.com/en/know/clinical-effectiveness-terms ©2023 UpToDate, Inc. and its affiliates and/or licensors. All rights reserved.
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