Taking a Nutrition History: A Practical Approach for Family Physicians (2024)

The association between nutrition and health has been clearly documented. Primary care physicians are expected to address nutrition and dietary behavior issues with their patients in the context of a brief clinical encounter. This article proposes the use of a short interview form, with specific suggestions for behavior changes that family physicians can use to help their patients meet currently accepted dietary guidelines. Answers to the questions on the interview form provide the physician with an overall sense of the patient's daily eating habits and help to identify major sources of saturated fat in the patient's diet. The patient is asked about the number of meals and snacks eaten in a 24-hour period, dining-out habits and frequency of consumption of fruits, vegetables, meats, poultry, fish, dairy products and desserts. Documentation of dietary changes can be accomplished using the suggested nutrition history form, and improvements in nutritional status can be measured using weight, blood pressure and laboratory test data.

Lifestyle issues and behavior changes are increasingly recognized as important aspects of preventive medicine.¹ Primary care physicians are expected to find the time to address these issues within the context of a brief clinical encounter. Given the family physician's role in assisting patients with lifestyle issues and the association between health promotion and disease prevention, it is clearly important to provide nutritional information and guidance to patients.

Unfortunately, most physicians are still not addressing dietary change in a comprehensive and effective manner.^2,3 Lack of time, inadequate nutrition training, poor reimbursem*nt for preventive services and lack of resources for referrals to registered dietitians have been identified as reasons for failure to provide nutrition screening and dietary intervention.^2–4 This article focuses on nutrition information that physicians can easily and quickly communicate to patients to help them improve their diets. Ten questions for patients are provided; the answers to these questions will quickly give family physicians information about the patient's food intake and will also provide an opportunity to offer dietary education and recommendations linked with behavior outcomes. The form helps family physicians identify and correct specific dietary deficiencies, excesses and behavior problems in individual patients.

Epidemiologic evidence continues to suggest that dietary fat—specifically, saturated fat—increases serum cholesterol levels, thus increasing the risk for cardiovascular disease.^5,6 Reducing fat consumption is an important step in reducing serum cholesterol and triglyceride levels, lowering the risk of cardiovascular disease and some cancers, and preventing and treating obesity.⁷ Recent evidence also supports the replacement of trans-unsaturated fats and saturated fats with monounsaturated and polyunsaturated fats as an effective way to prevent cardiovascular disease.⁸

According to the National Cholesterol Education Program⁹ and Healthy People 2000,¹⁰ dietary fat intake should be reduced to less than 30 percent of the daily intake of calories. According to the National Health and Nutrition Examination Survey (NHANES III),¹¹ which randomly selected a study group of 44,000 U.S. residents, the average American's diet contains 34 percent of calories as fat. This high percentage contributes to high rates of heart disease and cancer. Although dietary fat reduction is important for most Americans, physicians should be aware that this goal is not appropriate for all patients.¹²

Before attempting to improve patients' dietary habits or offer them nutritional guidance, it is necessary to assess their usual daily food intake. Nutrition questions should be routinely incorporated into the medical history. For example, when asking about medications, physicians could also ask patients if they are taking any vitamins, minerals, laxatives or other supplements. Next, patients can be asked specific questions about their typical food intake. Although a variety of methods for obtaining a diet history are available, the following set of questions is designed to identify major sources of saturated fat and give the physician an overall sense of a patient's eating habits. Each question is followed by potential “teaching points” that provide a rationale for the physician's recommendations. Gathering this information and instructing the patient should add no more than two to three minutes to a standard history, especially if the nutrition form is completed while the patient is in the waiting room (Figure 1).

How many meals and snacks do you eat in a 24-hour period?

A good way to begin is to ask patients what they consume during the day and night, to assess their overall intake. This information will also reveal irregular eating habits, such as consuming the majority of the day's calories in the evening. Obesity researchers at the University of Pennsylvania have offered this definition for the term “night-eating syndrome”: having no appetite for breakfast, eating 50 percent or more of total daily food intake at night and having difficulty falling asleep or staying asleep.¹³

Breakfast is an important meal because it offers the opportunity to eat low-fat, whole grain foods such as hot or cold cereal, which is also an excellent source of calcium if it includes skim or low-fat milk. Breakfast is intended to break the overnight fast, and a good breakfast helps prevent hunger and overeating later in the day. Older adults who live alone or are depressed often skip meals, thus increasing their risk of malnutrition.¹²

How many meals per week do you eat away from home?

Generally, meals eaten away from home contain more fat and calories than those prepared at home; they contain hidden sources of fat and are usually served in larger portions. “Supersized” and special promotional items at fast-food restaurants and cafeterias are often cheaper than single items and therefore offer a financial incentive for consuming extra fat and calories. Patients can be advised to follow these tips when eating out: select grilled, poached, baked or broiled entrees, have bread without butter, order sauces and salad dressings on the side and use them sparingly (or avoid them entirely), and skip dessert or order fruit or sherbet. Many fast-food restaurants now offer lower fat alternatives such as grilled fish or chicken breast served without added sauces, salads with low-fat dressing and baked potatoes.

How often do you eat high-fiber foods such as cereals, fruits and vegetables?

Epidemiologic evidence strongly supports an inverse association between fiber intake and cardiovascular disease, as well as cancers of the digestive tract.¹⁴ Soluble fiber, which is contained in cereal grains (especially oats and barley), citrus fruits, apples, beans and corn, has also been shown to reduce serum cholesterol and low-density lipoprotein levels.^15,16 Fresh fruits and vegetables are excellent sources of fiber and phytochemicals, which may explain their probable protective effect against certain cancers of the digestive tract.

Recent evidence strongly indicates that an elevated plasma hom*ocysteine level is an independent risk factor for atherosclerotic disease.¹⁷ Adequate intake of folate, vitamin B₆ and vitamin B₁₂ are required to keep hom*ocysteine levels normal; however, folate is the vitamin most often lacking in the average American's diet.¹¹ Folate is present primarily in dark-green leafy vegetables, whole-grain cereals, beans, oranges and orange juice. The American Cancer Society recommends at least five servings of fruits and vegetables and at least one serving of a fiber-rich cereal every day.¹⁶ Unfortunately, according to the NHANES III study,¹¹ only 23 percent of Americans eat five or more servings of fruits and vegetables every day.

How many times per week do you eat red meat, and what size is the usual portion?

A general rule of thumb is that patients who consume red meat more than four times per week are least likely to be following a low-fat diet. Since all animal protein sources contain both saturated fat and cholesterol, patients should limit protein intake to 10 to 20 percent of total calories, which translates to less than 7 oz of lean meat, fish and poultry per day. Processed meats, such as bacon, sausage, bologna, salami and hot dogs, are high in both saturated fat and calories, and intake of these should be limited. Patients can be encouraged to increase their consumption of low-fat vegetarian foods, such as red or navy beans, lentils, peas combined with rice, vegetarian “garden” burgers and pasta with tomato sauce. Patients should be advised to check nutrition labels for fat and calorie content. Generally, if the product contains more than 3 g of fat per 100 calories, it contains more than 30 percent fat calories (Figure 2).¹²

How many times per week do you eat poultry products, and what size is the usual portion?

The white meat of turkey and chicken has less total fat and saturated fat than red meat and should be substituted for red meat whenever possible (Figures 3 and 4).¹² The white meat of turkey contains only 8 percent fat and is leaner than the white meat of chicken, which is approximately 24 percent fat. However, the fat and calorie contents of both turkey and chicken increase significantly when the skin or the dark meat is eaten. Therefore, patients should be encouraged to grill, bake or broil the white meat of turkey or chicken and to remove the skin before eating. Portion sizes should be limited to 5 to 7 oz per day.

Turkey or chicken hot dogs are popularly considered to be a low-fat alternative to regular hot dogs. However, most turkey or chicken hot dogs contain approximately 70 percent fat, while a regular beef hot dog contains 80 percent fat, which is not much of a difference. Nonfat hot dogs are an excellent alternative.

How many times per week do you eat fish and shellfish, and what size is the usual portion?

Fish and shellfish are good alternatives to meat and poultry because of their low total-fat and saturated-fat content.¹² The cholesterol content in shellfish varies, but all shellfish is very low in total fat and saturated fat, and its consumption should therefore be encouraged. Fish also contains omega-3 fatty acids, which have been shown to decrease blood pressure and triglyceride levels, and increase clotting time.¹⁸ Recent research has shown that fish containing omega-3 fatty acids may help reduce the risk of cardiovascular disease when eaten as part of a heart-healthy diet. Additional studies have shown that eating fish high in omega-3 fatty acids at least once a week is associated with a reduction in the risk of primary cardiac arrest.¹⁹ The types of fish containing the highest amounts of omega-3 fatty acids are herring, salmon, mackerel, sardines and swordfish. Patients should be encouraged to eat fish and shellfish at least once per week and to order fish or shellfish when they eat out; they should also ask to have these items grilled or broiled rather than fried.

How many hours of television do you watch per day?

Environmental factors such as increased snacking while watching television most likely contribute to an association between obesity and television viewing.^20,21 An increased incidence of childhood obesity may be associated with a reduction in physical activity and an increased calorie intake.^20,22 According to the NHANES III study, 14 percent of children from six to 11 years of age and 12 percent of adolescents from 12 to 19 years of age are overweight.^22,23 These figures represent a significant increase from the NHANES II data (1976 to 1980), in which 7.6 percent of children and 5.7 percent of adolescents were found to be overweight.^22,23 Tracking studies continue to demonstrate that obese children are at increased risk of becoming obese adults and also incur the risk of developing associated medical problems.²⁴ Encourage your patients and their families to limit the number of hours spent watching television and to participate in after-school or after-work physical activities.

How often do you usually consume dairy products, and what type?

Since dairy products are an excellent source of calcium, it is not advised to reduce or eliminate consumption of these products, especially in women. Meeting calcium requirements throughout life is essential for proper skeletal growth and maturation. NHANES III data^25,26 reveal that most Americans do not consume adequate calcium and that older adults and teenagers have the greatest risk for a low calcium intake. Because of calcium's pivotal role in the normal development of healthy bones, new calcium guidelines established by the Institute of Medicine recommend intake levels associated with maximum retention of body calcium (Table 1).²⁷ For this reason, it is important to determine the amount, frequency and type of dairy products that your patients consume. Because certain dairy products such as regular cheese and whole milk contain a significant amount of saturated fat, low-fat or nonfat dairy products should be recommended. Low-fat mozzarella, ricotta, cottage and farmer's cheeses made from part-skim milk can be substituted for the whole-milk versions. Low-fat or nonfat yogurt and nonfat sour cream alternatives can be used to make dips and salad dressings. Non-dairy coffee creamers, whipped toppings and half-and-half are laden with saturated fats and should be avoided.

Patients who are lactose intolerant should be encouraged to use lactose-free dairy products (or to take products such as Lactaid) that are available in low-fat and nonfat forms. Patients should eat at least three to four servings of low-fat or nonfat dairy products every day. If it is not possible for certain patients to reach this level of calcium intake, supplements should be recommended.

How often do you eat desserts and sweets?

These foods are common sources of hidden saturated fats, since most commercially baked products contain butter and eggs. Fresh fruit, angel food cake, nonfat frozen yogurt and sherbet are the best alternatives. Other nonfat desserts are now available; however, the fat is usually replaced by increased amounts of simple sugars, so the calorie content may be equal to or sometimes greater than the fuller fat version. This increased calorie content is converted into fat in the body, thus defeating the intended purpose of eating nonfat foods. Encourage patients to read nutrition labels for both fat and calorie information when comparing products and to either share desserts with a partner or choose fruit or sherbet.

What types of beverages (including alcoholic) do you usually drink?

Regular soda, sweetened iced tea and juices contain significant calories and are not advisable for patients who are overweight (or those who have diabetes). Instead, patients can save hundreds of calories by drinking water with meals and snacks, and by limiting or diluting juices. Recent research indicates that consumption of 12 oz of juice or more per day is associated with obesity in young children.²⁸ The authors of this study advise parents and caretakers to limit young children's consumption of juice to less than 12 oz per day.²⁸

Alcohol intake should always be included as part of a patient's social history, because most people who drink alcohol to excess do not admit to having a drinking problem. According to the National Institute on Alcohol Abuse and Alcoholism, fewer than 40 percent of primary care physicians ask patients about their drinking habits during routine examinations.²⁹ Excessive alcohol consumption significantly increases the intake of “empty” calories (calories that can be used for energy but that do not contain vitamins or minerals). Numerous vitamin deficiencies are associated with chronic alcohol ingestion, including folate, thiamin, vitamin B₁₂ and possibly, vitamin C.¹² To begin, the physician can ask the patient the following questions: (1) Do you drink alcohol? (2) When was the last time you had a drink? (3) How often do you drink? (4) How many days per week do you usually have a drink? (5) Typically, on those days that you drink, how many drinks do you have?

Physicians may want to keep in mind that the dietary guidelines developed by the U.S. Department of Health and Human Services define moderate alcohol consumption as one drink per day for women and two drinks per day for men.³⁰

Even though no single diet is appropriate for all persons, taking a nutrition history will heighten patients' awareness of nutritional health and indicate to them that their physician is concerned about it. A nutrition history will also emphasize that diet is an important part of health maintenance. While it may not be possible to review all of these questions during one visit, one or two questions can be discussed at each visit. The physician can determine how much information to obtain and dispense at each visit based on the patient's condition, how often the patient visits the office and how motivated the patient is to make changes. Dietary changes can be documented using a nutrition history form (Figure 1). This form can become a permanent part of the patient's medical record. Improvements in nutritional status should also be documented using weight and blood pressure measurements, and laboratory data such as lipid and blood glucose levels.

Patients with acute or chronic diseases who require complex dietary changes should be referred to a registered dietitian. The information contained in this article should enable the family physician to encourage and support recommendations made by dietitians. Patients who have already accomplished some of their dietary goals should be congratulated and challenged to make further efforts to reduce dietary fat and calorie intake for both health promotion and disease prevention.¹