Evidence linking diet and chronic diseases has become more firmly
established in recent years. In addition to obesity it is not rare for
patients to have a secondary medical diagnosis with some relationship
to obesity. Many health problems can be overcome by a successful weight
loss program.
It is interesting to note that, in comparing results of a weight loss program, [The University of Massachusetts Medical Center. Study from 02/1987 - 12/1987.]
patients with multiple diagnoses demonstrated better results, at 1-year
follow-up, than patients with obesity and only one other diagnosis.
Diets for these patients with multiple diagnoses were more complex, but
perhaps these patients felt more concerned about their health and thus
were more motivated.
Table 2.14 Results at 1-year follow-up of secondary diagnoses.
| Diagnosis | No. | Maintained or lost weight | Success |
| Obesity alone | 15 | 13 | 87% |
| Diabetes | 11 | 9 | 82% |
| High cholesterol | 12 | 6 | 50% |
| Hypertension | 9 | 4 | 44% |
| Back pain | 5 | 4 | 80% |
| Coronary artery disease | 4 | 3 | 75% |
| Pulmonary disease | 1 | 1 | 100% |
| Diabetes & hypertension | 5 | 5 | 100% |
| Hypertension & high cholesterol | 5 | 4 | 80% |
| Diabetes & high cholesterol | 2 | 1 | 50% |
| Hypertension & arthritis | 2 | 2 | 100% |
| Hypertension and lower back pain | 1 | 1 | 100% |
| Hypertension and coronary artery disease | 1 | 1 | 100% |
Heart disease and cancer are the leading causes of death in the
United States. Healthful eating habits can help prevent those diseases.
Studies have identified three major risk factors for coronary heart
disease: smoking, hypertension, and elevated plasma or serum
cholesterol. Other studies have shown that quitting smoking, and
reducing blood pressure and blood cholesterol reduce the risk for heart
disease. Thus, considerable effort has been devoted to the modification
of these risk factors.
Recently, the results of the Lipid Research Clinics Coronary Primary
Prevention Trial prompted a nationwide effort to increase public
awareness of cholesterol and coronary heart disease and to encourage
the adoption of low-fat, low-cholesterol diets.
To implement a cholesterol-lowering diet effectively, a patient must
acquire a substantial body of knowledge. The basic components of a diet
to lower blood lipids include reducing total fat, particularly
saturated fat, maintaining or increasing polyunsaturated fat and
changing sources of monounsaturated fat, decreasing dietary
cholesterol, and increasing carbohydrate and fiber.
In practical terms, this means that individuals must learn to
identify major sources of these macronutrients in foods available for
their consumption. It is not sufficient for patients to know that they
must avoid saturated fats and cholesterol. You need to be able to
implement changes when shopping, preparing food, or eating away from
home. The knowledge required to implement a cholesterol-lowering diet
is outlined as follows:
- General knowledge:Understanding the relationship of
blood cholesterol and dietary factors. Processing realistic
expectations regarding the effects of diet. Knowing the effects of
dietary lapses on blood lipids. Understanding genetic influences on
blood lipids. - Fats:Understanding the difference between saturated
and polyunsaturated fats. Knowing how to read product labels to
determine appropriateness of fat content. Possessing sufficient
knowledge to interpret ambiguous and sometimes misleading information
on product labels, such as "may contain one of the following..." or
"contains no cholesterol" (just lots of saturated fats). - Cholesterol:Understanding the difference between
other fats and cholesterol. Awareness of which foods are high in
cholesterol, including some awareness as to the amount of cholesterol
present in various foods. - Fiber:Knowledge about which foods are high in fiber. Understanding the importance of soluble versus insoluble fiber.
- Cooking techniques:Ability to identify cooking
techniques that are least likely to contribute to high fat content in
food. Ability to execute the appropriate cooking techniques. - Eating in restaurants and Purchasing prepared food:Ability
to recognize which of a variety of food choices is lowest in fat and
cholesterol and higher in fiber. Understanding which questions to ask
the food preparer in order to make the best choices possible.
Eating is a social activity, and is one of the behaviours related to
cardiovascular disease that is influenced by the social environment.
Variability in blood lipids can also be attributed to the environment;
there is evidence that spouses' cholesterol and triglyceride levels are
similar and that husbands and wives consume similar quantities of eggs
and whole milk. [Barret-Connor, E., Suarez, L., and Criqui, M.H.:
Spouse concordance of plasma cholesterol and triglyceride. J Chronic
Disease 35:333, 1982.]
The importance of including a patient's spouse or family in
counselling to reduce the risk of cardiovascular disease has been
recognized and has received some attention in the literature on weight
loss. Including a spouse or other partner is advocated in obesity
treatment programs. Although application to cholesterol-lowering diets
is limited, there is some empirical evidence that inclusion of the
spouse facilitates weight loss in the treatment of obesity.
Mere inclusion of the spouse as an observer may not be sufficient to
enhance treatment effectiveness and may even be counterproductive.
Spouses should be encouraged to assume an active role in assisting with
adherence to low-fat, low-cholesterol diets.
Table 2.15 Estimated Total Deaths for the 10 Leading Causes of Death; United States, 1987.
| Rank | Cause of Death | Number | % |
| 1* | Heart diseases (Coronary heart disease) (Other heart disease) | 759,400 (511,700) (247,700) | 35.7 (24.1) (11.6) |
| 2* | Cancers | 476,700 | 22.4 |
| 3* | Strokes | 148,700 | 7.0 |
| 4 | Unintentional injuries (Motor vehicle) (All others) | 92,500 (46,800) (45,700) | 4.4 (2.2) (2.2) |
| 5 | Chronic obstructive lung diseases | 78,000 | 3.7 |
| 6 | Pneumonia and influenza | 68,600 | 3.2 |
| 7* | Diabetes mellitus | 37,800 | 1.8 |
| 8 | Suicide | 29,600 | 1.4 |
| 9 | Chronic liver disease and cirrhosis | 26,000 | 1.2 |
| 10* | Atherosclerosis | 23,100 | 1.1 |
| All causes | 2,125,100 | 100.0 |
* Causes of death in which diet plays a part.
[Source: National Center for Health Statistics, 1988.]
Coronary Heart Disease. Despite the recent sharp decline in
death from this condition, CHD still accounts for the largest number of
deaths in the United States. In 1985, illness and deaths from CHD cost
Americans an estimated $49 billion in direct health care expenditures
and lost productivity.
Stroke. Strokes occur in about 500,000 persons per year in
the United States, resulting in about 150,000 deaths. Approximately 2
million living Americans suffer from stroke-related disabilities, at an
estimated annual cost of more than $11 billion.
High Blood Pressure (Hypertension). Hypertension is a major
risk factor for both heart disease and stroke. About 58 million people
in the United States have hypertension. The occurrence of hypertension
increases with age and is higher for black Americans (of which 38
percent are hypertensive) than for white Americans (2 percent).
Cancer. More than 475,000 persons died of cancer in the
United States in 1987. During the same period, more than 900,000 new
cases of cancer occurred. In 1985 the total costs for direct health
care and lost productivity due to cancer was estimated to be $72
billion.
Diabetes Mellitus. Approximately 11 million Americans have
diabetes. In addition to the nearly 38,000 deaths in 1987 attributed
directly to this condition, diabetes also contributes to an estimated
95,000 deaths per year from associated cardiovascular and kidney
complications. In 1985, diabetes was estimated to cost $13.8 billion
per year.
Obesity. Obesity affects approximately 34 million adults in
the United States. Obesity is a risk factor for coronary heart disease,
high blood pressure, diabetes, and possibly some types of cancer as
well as other chronic diseases.
Osteoporosis. Approximately 20 million Americans are affected
by osteoporosis, which contributes to some 1.5 million bone fractures
per year in persons 45 years and older. The total costs of osteoporosis
to the U.S. economy were estimated to be $10 billion in 1983.
Dental Diseases. Although dental caries among children, as
well as some forms of adult periodontal disease, appear to be
declining, the overall prevalence of these conditions imposes a
substantial burden on Americans. The costs of dental care were
estimated at $21.3 billion in 1985.
Diverticular Disease. Because most persons with diverticular
disease do not have symptoms, the true prevalence of this condition is
unknown. In 1980, diverticulosis was accountable for some 200,000
hospitalizations.
In assessing the role that diet might play in prevention of these
conditions it must be understood that they are caused by a combination
of multiple environmental, behavioural, social, andgenetic factors. The
exact proportion that can be attributed directly to diet is uncertain.
Although some experts have suggested that dietary factors overall are
responsible for perhaps a third or more of all cases of cancer, and
coronary heart disease, such suggestions are based on interpretations
of research studies that cannot completely distinguish dietary from
genetic, behavioural, or environmental causes.
Nonetheless, it is now clear that diet contributes in substantial
ways to the development of these diseases and that modification of diet
can contribute to their prevention. The magnitude of the health and
economic cost of diet-related disease suggests the importance of the
dietary changes suggested.
Clearly emerging as the primary priority for dietary change is the
recommendation to reduce intake of total fats, especially saturated
fat, because of their relationship to several chronic disease
conditions. Because excess body weight is a risk factor for several
chronic diseases, maintenance of desirable weight is also an important
public health priority. Evidence further supports the recommendation to
consume a dietary pattern that contains a variety of foods, provided
that these foods are low in calories, fat, cholesterol, and sodium.
Taken together these recommendations promote a dietary pattern that
emphasizes consumption of vegetables, fruits, and whole grain products
- foods that are rich in complex carbohydrates and fiber and relatively
low in calories. And of fish, poultry, prepared without the skin, lean
meats, and low-fat dairy products selected to minimize consumption of
total fat, saturated fat, and cholesterol.
The evidence presented here suggests that such overall dietary
changes will lead to substantial improvements in the nutritional
quality of the diet.
The evidence also suggests that most people generally need not
consume nutrient supplements. Although nutrient supplements are usually
safe in amounts corresponding to the Recommended Dietary Allowances,
there are no known advantages to healthy people consuming excess
amounts of any nutrient, and amounts greatly exceeding RDAs can be
harmful. Toxicity has been reported for most minerals and trace
elements, as well as some vitamins, indicating that excessive
supplementation with these substances can be hazardous. [The Surgeon General's Report on Nutrition and Health, Prepublication copy, 1988.]
