Disease Prevention Through Diet & Nutrition

1. Healthy Eating Slideshow: Fat-Fighting Foods
2. Food Frauds Slideshow Pictures
3. Take the Diet & Nutrition Quiz

Medical Author:

Dennis Lee, MD

Dennis Lee, MD

Dr. Lee was born in Shanghai, China, and received his college and medical training in the United States. He is fluent in English and three Chinese dialects. He graduated with chemistry departmental honors from Harvey Mudd College. He was appointed president of AOA society at UCLA School of Medicine. He underwent internal medicine residency and gastroenterology fellowship training at Cedars Sinai Medical Center.

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Medical Author:

Melissa Conrad Stöppler, MD

Melissa Conrad Stöppler, MD

Melissa Conrad Stöppler, MD, is a U.S. board-certified Anatomic Pathologist with subspecialty training in the fields of Experimental and Molecular Pathology. Dr. Stöppler's educational background includes a BA with Highest Distinction from the University of Virginia and an MD from the University of North Carolina. She completed residency training in Anatomic Pathology at Georgetown University followed by subspecialty fellowship training in molecular diagnostics and experimental pathology.

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Medical Editor:

William C. Shiel Jr., MD, FACP, FACR

William C. Shiel Jr., MD, FACP, FACR

Dr. Shiel received a Bachelor of Science degree with honors from the University of Notre Dame. There he was involved in research in radiation biology and received the Huisking Scholarship. After graduating from St. Louis University School of Medicine, he completed his Internal Medicine residency and Rheumatology fellowship at the University of California, Irvine. He is board-certified in Internal Medicine and Rheumatology.

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Here are three reasons why following a healthy diet is important:

1. to maintain health by preventing loss of muscle strength, bone mass, and vitamin deficiency states;
2. to prevent diseases such as heart attacks, strokes, obesity, osteoporosis, and certain cancers; and
3. to help control and/or treat chronic diseases and conditions such as high blood pressure, diabetes mellitus, and celiac disease.

The body requires carbohydrates, fats, proteins, vitamins, and minerals to maintain healthy organs, bones, muscles, 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.

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 is caused by eating more calories than the body burns. Obesity, in turn, can be a cause of many diseases such as heart disease, diabetes, liver disease, arthritis, high blood pressure, gout, gallstones, and certain cancers.

To lose weight or maintain a healthy weight, one needs 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 2005 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:

• emphasize fruits, vegetables, whole grains, and fat-free or low-fat milk and milk products;
• include lean meats, poultry, fish, beans, eggs, and nuts; and
• be low in saturated fats, trans fats, cholesterol, salt (sodium), and added sugars.

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.