Maintaining a healthy diet is the practice of making choices about what to eat with the intent of improving or maintaining good health. Usually this involves consuming necessary nutrients by eating the appropriate amounts from all of the food groups. Since human nutrition is complex, a healthy diet may vary widely subject to an individual's genetic makeup, environment, and health. For around 20% of the planet's population, lack of food and malnutrition are the main impediments to healthy eating; people in developed countries have the opposite problem and are more concerned about obesity.
Generally, a healthy diet is said to include:
- Sufficient calories to maintain a person's metabolic and activity needs, but not so excessive as to result in fat storage greater than roughly 30% of body mass. 2,000 is the recommended daily allowance of calories for most people, but it depends on age, gender, height, and weight. (see Body fat percentage)
- Sufficient quantities of fat, including monounsaturated fat, polyunsaturated fat and saturated fat, with a balance of omega-6 and long-chain omega-3 lipids. 65 grams is the recommended daily allowance of fat.
- Maintenance of a good ratio between carbohydrates and lipids (4:1): four grams of the first for one gram of the second.
- Avoidance of excessive saturated fat (although the "evidence" for this claim is forever in debate after the testimony of results provided by the Framingham Heart Study of 1948-1998)
- Avoidance of trans fat.
- Sufficient essential amino acids ("complete protein") to provide cellular replenishment and transport proteins. (All essential amino acids are present in animals. Some plants together give all the essential acids ex. rice and beans.)
- 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);
- Avoiding chronic high doses of certain foods that are benign or beneficial in small or occasional doses, such as:
- - foods or substances with directly toxic properties at high chronic doses (e.g. ethyl alcohol);
- - foods that may interfere at high doses with other body processes (e.g. refined table salt);
- - foods that may burden or exhaust normal functions (e.g. refined carbohydrates without adequate dietary fiber).
13 keys to a healthy diet
Developing healthy eating habits isn't as confusing or as restrictive as many people imagine. The first principle of a healthy diet is simply to eat a wide variety of foods. This is important because different foods make different nutritional contributions. Secondly, fruits, vegetables and grains - foods high in complex carbohydrates, fiber, vitamins and minerals, low in fat and free of cholesterol - should make up the bulk of the calories you consume. The rest should come from low-fat dairy products, lean meat, poultry and fish. You should also try to maintain a balance between calorie intake and calorie expenditure - that is, don't eat more food than your body can utilize. Otherwise, you will gain weight. The more active you are, therefore, the more you can eat and still maintain this balance. Following these three basic steps doesn't mean that you have to give up your favorite foods. As long as your overall diet is balanced and rich in nutrients and fiber there is nothing wrong with an occasional cheeseburger. Just be sure to limit how frequently you eat such foods and try to eat small portions of them. You can also view healthy eating as an opportunity to expand your range of choices by trying foods—especially vegetables, whole grains, or fruits - that you don't normally eat. A healthy diet doesn't have to mean eating foods that are bland or unappealing. The following basic guidelines are what you need to know to construct a healthy diet.
- Eat plenty of high-fiber foods - fruits, vegetables, beans, and whole grains. These are the "good" carbohydrates - nutritious, filling, and relatively low in calories. They should supply the 20 to 30 grams of dietary fiber you need each day, which slows the absorption of carbohydrates, so there’s less effect on insulin and blood sugar, and provides other health benefits as well. Such foods also provide important vitamins, minerals, and phytochemicals (plant chemicals essential to good health).
- Make sure to include green, orange, and yellow fruits and vegetables - such as broccoli, carrots, cantaloupe, and citrus fruits. The antioxidants and other nutrients in these foods may help protect against developing certain types of cancer and other diseases. Eat five or more servings a day.
- Limit your intake of sugary foods, refined-grain products such as white bread, and salty snack foods. Sugar, our No.1 additive, is added to a vast array of foods. Just one daily 12-ounce can of soda (160 calories) can add up to 16 pounds over the course of a year. Many sugary foods are also high in fat, so they’re calorie-dense.
- Cut down on animal fat. It’s rich in saturated fat, which boosts blood cholesterol levels and has other adverse health effects. Choose lean meats, skinless poultry, and nonfat or low-fat or nonfat dairy products.
- Cut way down on trans fats, supplied by hydrogenated vegetable oils used in most processed foods in the supermarket and in many fast foods.
- Eat more fish and nuts, which contain healthy unsaturated fats. Substitute olive or canola oil for butter or stick margarine.
- Keep portions moderate, especially of high-calorie foods. In recent years serving sizes have ballooned, particularly in restaurants. Choose a starter instead of an entrée, split a dish with a friend, and don’t order supersized anything.
- Keep your cholesterol intake below 300 milligrams per day. Cholesterol is found only in animal products, such as meats, poultry, dairy products and egg yolks.
- Eat a variety of foods. Don't try to fill your nutrient requirements by eating the same foods day in, day out. It is possible that not every essential nutrient has been identified, and so eating a wide assortment of foods helps to ensure that you will get all the necessary nutrients. In addition, this will limit your exposure to any pesticides or toxic substances that may be present in one particular food.
- Maintain an adequate calcium intake. Calcium is essential for strong bones and teeth. Get your calcium from low-fat sources, such as skim milk and low-fat yogurt. If you can't get the optimal amount from foods, take supplements.
- Try to get your vitamins and minerals from foods, not from supplements. Supplements cannot substitute for a healthy diet, which supplies nutrients and other compounds besides vitamins and minerals. Foods also provide the "synergy" that many nutrients require to be efficiently used in the body.
- Maintain a desirable weight. Balance energy (calorie) intake with energy output. Exercise and other physical activity are essential.
- If you drink alcohol, do so in moderation. That is one drink a day for women, two a day for men. A drink is defined as 12 ounces of beer, 4 ounces of wine, or 1.5 ounces of 80-proof spirits. Excess alcohol consumption leads to a variety of health problems. And alcoholic beverages can add many calories to your diet without supplying nutrients.
The benefits of a healthy diet
- Meeting your nutritional needs - A varied, balanced intake provides the nutrients you need to avoid nutritional deficiencies. This also includes non-nutrients, such as fiber.
- Preventing and treating disease - One of the key benefits of a healthy diet is that it can help prevent you from developing certain diseases, such as cancer and heart disease. It is also helpful in treating other ailments such as diabetes and high blood pressure.
- Enjoying life - There are other benefits of a healthy diet. Food is an important part of many social events, and is a major way of connecting with other people. Cooking fresh, wholesome meals can be an enjoyable way to spend time, whether alone or with others.
- Managing your weight - Eating well is crucial if you are to maintain a suitable weight. Eating the wrong food, or simply over-eating, will lead to weight gain, and all the problems associated with it.
Essential Vitamins and Minerals
- Vitamin A (Beta Carotene) - Helps regulate the immune system. Sources: carrots, peppers, green leafy vegetables such as spinach.
- Vitamin C - Essential for the healing of wounds, and the repair and maintenance of cartilage, bones, and teeth. Sources: citrus fruits, tomatoes and spinach.
- Vitamin D - Helps maintains bone health and the absorption of calcium. Sources: vitamin-fortified dairy products and cereals.
- Iron - Helps red blood cells carry oxygen to all parts of the body. Sources: green vegetables, beans, poultry and red meat; best sources are supplements.
- Calcium - Considered one of the most important minerals for the growth, maintenance, and reproduction of the human body. Sources: dairy products, kale, spinach, supplements.
- Potassium - Helps with muscle and nervous system function and helps balance water in blood and tissues. Sources: bananas, other fruits and vegetables.
- Zinc - Helps in the proper functioning of the immune system and plays a role in the metabolism of carbohydrates. Sources: red meat and supplements.
- Magnesium - Helps with muscle and nervous system functioning and the production of energy and protein. Sources: fruits, vegetables and whole grains.
Guidelines for developing a plan for healthy eating
By committing to eating better you can reduce your risk of many chronic diseases – including heart disease, diabetes, osteoporosis and certain cancers – while increasing your energy and stamina. Healthy eating can even lower “bad” LDL cholesterol as much as low-dose station drugs! By developing your own plan for healthy eating you’ll be able to expand your range of healthy choices to include a variety of foods, especially delicious vegetables, grains and fruits that you may have previously ignored.
Committing to a healthy diet is the easiest way to improve your overall health. Healthy foods help your body function by providing energy, strengthening immunity, and improving your ability to stay fit and active. Go for the bright: the deeper the color, the greater the concentration of vitamins, minerals and antioxidants. Dark green and orange vegetables, from broccoli, kale and mustard greens to butternut squash and sweet potatoes, are several excellent choices. Dried beans and peas, such as black beans, kidney beans and tofu, count in the vegetable category as well as the meat group. 100 percent vegetable juice counts, too. Fruits can be enjoyed a number of ways: fresh, canned, frozen, dried, whole, cut-up, or pureed. Go easy on the fruit juices, though; they contain a lot of natural sugars. Besides the standards such as apples, bananas, oranges, peaches, pears and plums, try mangoes, blackberries, papayas, hybrid melons and avocados.
As part of a healthy diet, the USDA recommends choosing fat-free or low-fat dairy products. If you're lactose-intolerant, there are lactose-free and lower-lactose products, such as hard cheeses and yogurt. Harvard Health suggests a dairy or calcium supplement as an alternative to milk and cheese, which can contain a lot of saturated fat. This group includes fish, poultry, eggs, beans, peas, nuts and seeds, so it's easy to vary your healthy eating choices. Harvard Health suggests avoiding red meats because they contain a lot of saturated fat. Oils are a major source of fats in your diet. Common plant and fish oils include: canola oil, corn oil, cottonseed oil, olive oil, safflower oil, soybean oil, and sunflower oil.
The USDA Food Pyramid includes a discretionary calories classification, which include “the extras” like solid fats, added sugars, and alcohol, or more food from any food group. Alternatively, Harvard Health suggests that alcohol is okay in moderation and that sweets should be avoided.