CHAPTER 1
INTRODUCTION

The foods you choose to eat can have a direct impact on your ability to enjoy life to its fullest. Perhaps the most obvious positive effect of food is the pleasurable feeling you get from eating a good-tasting meal. It might be a plate of grilled chicken, corn-on-the-cob, fresh vine-ripened tomatoes, and a baked potato, or a steaming dish of spaghetti topped with a zesty tomato sauce.

Your diet can have long-term effects on your health as well. Diet plays a major role in promoting and maintaining good health, preventing some chronic diseases and treating others, and speeding recovery from injuries. In earlier times, diseases such as goiter and pellagra were relatively common—both are caused by nutritional deficiencies and cured by diets containing sufficient amounts of a particular nutrient. In the case of goiter, iodine is the missing nutrient; with pellagra it is mainly niacin, a B vitamin. These diseases are rare today in the United States because most Americans get enough of these essential nutrients in their diets.



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Eat for Life: The Food and Nutrition Board's Guide to Reducing Your Risk of Chronic Disease CHAPTER 1 INTRODUCTION The foods you choose to eat can have a direct impact on your ability to enjoy life to its fullest. Perhaps the most obvious positive effect of food is the pleasurable feeling you get from eating a good-tasting meal. It might be a plate of grilled chicken, corn-on-the-cob, fresh vine-ripened tomatoes, and a baked potato, or a steaming dish of spaghetti topped with a zesty tomato sauce. Your diet can have long-term effects on your health as well. Diet plays a major role in promoting and maintaining good health, preventing some chronic diseases and treating others, and speeding recovery from injuries. In earlier times, diseases such as goiter and pellagra were relatively common—both are caused by nutritional deficiencies and cured by diets containing sufficient amounts of a particular nutrient. In the case of goiter, iodine is the missing nutrient; with pellagra it is mainly niacin, a B vitamin. These diseases are rare today in the United States because most Americans get enough of these essential nutrients in their diets.

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Eat for Life: The Food and Nutrition Board's Guide to Reducing Your Risk of Chronic Disease Although it is unlikely that you or your family will ever suffer from an illness caused by pronounced dietary deficiency, the foods you eat can exert more subtle and, in the long run, no less harmful effects on your health. During the past few decades, scientists have identified several dietary factors that play important roles in the development of specific diseases. Diets high in certain types of fat, for example, appear to increase the risk of developing coronary heart disease and certain cancers, and, among susceptible people, too much salt in food is believed to increase the chances of developing hypertension (high blood pressure). Other scientific evidence suggests that the current average American diet—which is high in fatty foods and low in fruits and vegetables—can increase the risk of developing certain forms of cancer, especially cancers of the esophagus, colon (large bowel), prostate, and breast. Certain dietary patterns can increase the likelihood of dental caries (cavities). In addition, habitually eating more calories than the body uses for maintenance and physical activity produces obesity and increases the risk of several chronic diseases including noninsulin-dependent diabetes mellitus, a form of diabetes that does not usually require daily insulin injections but has many adverse complications and generally appears after age 40. As the body of research on diet-disease connections has grown over the past half century, scientists, policymakers, officials of the food industry, consumer groups, and others have engaged in a debate about how much and what kind of evidence justifies giving dietary advice to the public. They have also argued about how best to control risk factors on which there is general agreement among scientists. The central problem in this debate is one that characterizes all science: absolute proof is difficult to obtain. This is particularly true in a science such as nutrition, in which many factors—age, sex, genetics, social behavior, and cultural differences, for example—can play a role in what food we eat and how it affects our bodies.

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Eat for Life: The Food and Nutrition Board's Guide to Reducing Your Risk of Chronic Disease Nevertheless, the strength of the evidence, the severity of the risk, and the ability of people to make informed choices can be used as a foundation for making public policy decisions on diet and health. Public information and education programs may be appropriate in some cases, and government regulation in others. For example, it might be sufficient to educate people against the potential hazard of eating too much fatty food, but the cancer-causing potential of aflatoxin (a toxin produced by a mold that grows on food) and the fact that it cannot be seen in food warrant government regulation to curtail aflatoxin contamination of peanuts, grains, and milk. Other criteria might come into play as well: the likelihood that a particular nutritional factor will trigger an increase in a chronic disease, the severity of that disease, the number of people likely to be affected, and estimates of whether people will change their eating habits in response to this risk. DEVELOPING NUTRITIONAL GUIDELINES To pin down diet-disease connections with an eye to providing the best possible dietary advice to the American public, the scientists of the Committee on Diet and Health of the Food and Nutrition Board (then under the National Research Council and since 1988 under the Institute of Medicine) reviewed thousands of pertinent studies. Most of the material in Eat for Life comes from the much larger volume Diet and Health: Implications for Reducing Chronic Disease Risk (National Academy Press, 1989), which was the primary result of that review. The committee's charge was to determine what dietary constituents, if any, play a role in the occurrence of chronic diseases. Furthermore, the committee members were to recommend dietary changes that would promote longer, healthier lives for the general public of the United States by

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Eat for Life: The Food and Nutrition Board's Guide to Reducing Your Risk of Chronic Disease reducing the risk of chronic illness caused by current dietary practices. Several other expert groups have also addressed the importance of dietary factors to the public's health (see chapter 2). But aside from the recent Surgeon General's Report on Nutrition and Health (U.S. Government Printing Office, 1988), these other groups have focused primarily on identifying dietary risk factors for single diseases. The committee members decided that there is still much to be learned about diet and its role in chronic diseases. But they also concluded that it would be wrong to ignore the large body of existing evidence supporting a link between nutrition and chronic disease while waiting for absolute proof of the benefits that we as a nation, and as individuals, would gain from making certain changes in our diets. After all their deliberations, the committee members decided that the overall evidence for a relationship between certain dietary patterns—a diet high in saturated fatty acids and total fat, for example—and chronic diseases—such as heart attacks and certain cancers—supports three actions. First, they devised the nine dietary guidelines that are the basis of Eat for Life. Second, they concluded that there should be a comprehensive attempt to inform the public about the likelihood of certain risks and the possible benefits of dietary changes. That is the role of this book, as well as other efforts by the press, scientists, nutritionists, physicians, and public officials. Third, the committee strongly believes that government and the food industry should take steps to make it easier for us to change our diets. For example, beef producers should develop leaner meat that will make it easier to reduce the amount of fat in our diets. In the same vein, food processors should use less salt and saturated fat in their products, and fast-food chains sh ould introduce lower-calorie and

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Eat for Life: The Food and Nutrition Board's Guide to Reducing Your Risk of Chronic Disease lower-fat items to their menus. Government at all levels—federal, state, and local—should adopt policies and programs that promote the recommended changes and eating patterns. AN EATING PATTERN FOR LIFE–NOT A “DIET” The nine dietary guidelines devised by the committee can help reduce your risk of developing heart disease, hypertension, various forms of cancer, dental caries, obesity, noninsulin-dependent diabetes, osteoporosis, and chronic liver disease. These nine dietary guidelines are laid out in Table 1.1 and described in Chapter 2. The thing to remember when you read these guidelines is that they are not the rules of a ''diet". The eating pattern outlined in this book does not revolve around sacrifice. The eating pattern can work within the framework of any ethnic cuisine. It is not a list of foods you can and cannot eat, nor is it a series of menu plans to which you must adhere. Following this pattern is not expensive, and it may even lower your food bills. It is certainly not a complicated process that involves weighing food, dishing out exactly measured portions, or calculating the nutritional content of every meal you eat. The nine dietary guidelines are just that: guidelines. They provide the foundation upon which you can build a sensible dietary pattern that suits your particular needs and tastes. These guidelines, in essence, form an eating pattern for life and provide you with a philosophy of eating that can guide you as you plan meals, cook, shop, and eat out Of course, following the guidelines may require you to make some changes in the way you eat. But those changes will be evolutionary, not revolutionary—you do not have to become a vegetarian, for instance, or eat exotic foods that you can find only at health food or specialty stores. You will learn to trim fat from the meat you eat—but you do not have to

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Eat for Life: The Food and Nutrition Board's Guide to Reducing Your Risk of Chronic Disease TABLE 1.1 The nine dietary guidelines 1. Reduce total fat intake to 30 percent or less of your total calorie consumption. Reduce saturated fatty acid intake to less than 10 percent of calories. Reduce cholesterol intake to less than 300 milligrams (mg) daily. 2. Eat five or more servings of a combination of vegetables and fruits daily, especially green and yellow vegetables and citrus fruits. Also, increase your intake of starches and other complex carbohydrates by eating six or more daily servings of a combination of breads, cereals, and legumes. 3. Eat a reasonable amount of protein, maintaining your protein consumption at moderate levels. 4. Balance the amount of food you eat with the amount of exercise you get to maintain appropriate body weight. 5. It is not recommended that you drink alcohol. If you do drink alcoholic beverages, limit the amount you drink in a single day to no more than two cans of beer, two small glasses of wine, or two average cocktails. Pregnant women should avoid alcoholic beverages. 6. Limit the amount of salt (sodium chloride) that you eat to 6 grams (g) (slightly more than 1 teaspoon of salt) per day or less. Limit the use of salt in cooking and avoid adding it to food at the table. Salty foods, including highly processed salty foods, salt-preserved foods, and salt-pickled foods, should be eaten sparingly, if at all. 7. Maintain adequate calcium intake. 8. Avoid taking dietary supplements in excess of the U.S. Recommended Daily Allowances (U.S. RDAs) in any one day. 9. Maintain an optimal level of fluoride in your diet and particularly in the diets of your children when their baby and adult teeth are forming.

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Eat for Life: The Food and Nutrition Board's Guide to Reducing Your Risk of Chronic Disease give up meat by any means, and you will eat more bread, pasta, potatoes, vegetables, and fruits. This book is designed to help you and your family make beneficial changes in the way you eat with a minimum of effort and a maximum of effect. Along with each guideline in Chapter 2 is a short discussion on how it can help protect your health. The chapters that follow provide enough information about the links between diet and chronic illness to convince you of the need to alter your current eating pattern. And in Chapter 10 you will find practical advice on how to follow the guidelines easily in your everyday life and how to avoid common nutritional pitfalls. In the end, you will probably be surprised at how easy it is to eat healthfully and to enjoy your meals today without compromising your health in the future.

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