Here are three reasons why following a healthy diet is important:
- to maintain health by preventing loss of muscle strength, bone mass, and vitamin deficiency states;
- to prevent diseases such as heart attacks, strokes, obesity, osteoporosis, and certain cancers; and
- to help control and/or treat chronic diseases and conditions such as high blood pressure, diabetes mellitus, sleep apnea, and celiac disease.
The body requires carbohydrates, fats, proteins, vitamins, and minerals to maintain healthy organs, bones, muscles, and nerves, and to produce hormones and chemicals that are necessary for the proper function of organs.
Vitamins and minerals are naturally occurring substances that are essential for the growth and function of the body. Vitamins and minerals are both necessary (in small amounts) for normal chemical reactions (metabolism) in the body.
Preventing and controlling diseases
Obesity and heart attacks are major public-health problems in the United States and other countries. Therefore, most dietary recommendations are aimed at preventing these two diseases. Obesity comes over time by eating more calories than the body burns. Obesity, in turn, can contribute to the development of many diseases such as heart disease, diabetes, sleep apnea, liver disease, arthritis, high blood pressure, gout, gallstones, and certain cancers.
To lose weight or maintain a healthy weight, it helps to eat more low-energy-dense foods. Low-energy-dense foods (such as vegetables and fruits) contain few calories per unit volume of food so that one can eat a large volume of it (for example, lettuce) without taking in many calories. One should also eat less of the high-energy-dense foods such as fats, egg yolks, fried foods, sweets, and high-fat salad dressings. Foods with a high energy density also often have high cholesterol and saturated fat content. One should also eat less of those foods that provide calories but little other nutrients, such as alcohol and many packaged snack foods.
The Dietary Guidelines for Americans, published in 2010 by the United States Department of Agriculture (USDA), contains guidelines for healthy diets based upon review of scientific studies for people above 2 years of age. These guidelines recommend that a healthy diet should:
- balance calories with physical activity to manage weight;
- consume more of certain foods and nutrients such as fruits, vegetables, whole grains, fat-free and low-fat dairy products, and seafood;
- consume fewer foods with sodium (salt), saturated fats, trans fats, cholesterol, added sugars, and refined grains.
MyPyramid is an online animated program to help a person customize his/her diet by choosing proper foods and portion sizes based on the individual's age, sex, and activity level. The key objectives of the MyPyramid Plan are to help a person get the most nutrition (proteins, vitamins, and minerals) out of the recommended number of daily calories and to achieve a balance between food intake and physical activity to maintain a healthy weight. The MyPyramid Plan recommendations include:
- Make half your grains whole.
- Vary your veggies.
- Focus on fruit.
- Get your calcium-rich foods.
- Go lean with protein.
- Find your balance between food and physical activity.