Reproducibility and comparability of a computerized, self-administered food frequency questionnaire.

A self-administered dietary assessment questionnaire was developed for the microcomputer to identify individuals whose dietary patterns may put them at risk for cancer. It was tested among 50 adult volunteers in a New York school district. The quantitative food frequency portion of the questionnaire (FFQ), administered twice one month apart, was reproducible for calories, fat, percentage of calories from fat, cholesterol, vitamin A, vitamin C, calcium, and dietary fiber (Spearman r = 0.56-0.87). To test for relative validity, individual nutrient intake calculated from each administration of the FFQ was compared with the nutrient intake calculated from seven-day food records collected one month after the second FFQ administration. Nutrient intake from the first and second FFQ compared with food record nutrient intake yielded a Spearman's correlation coefficient of 0.58 and 0.62, respectively, for percentage of kilocalories from fat. No significant difference in mean intake of percentage of calories from fat was found between the FFQ 1 and FFQ 2 or between the FFQs and the food record. However, there were significant differences between mean food record and FFQ estimates of kilocalories, fat, vitamin A, vitamin C, calcium, and dietary fiber. We concluded that computerized nutrient assessment, which utilizes the subject in data entry, may be suitable for some clinical and educational uses and research studies of intake of fat as a percentage of calories among healthy adults.

Diet intervention methods to reduce fat intake: nutrient and food group composition of self-selected low-fat diets.

A multicentered pilot study was conducted to test an intervention protocol designed to reduce fat intake to 15% of energy intake. Eligible subjects were postmenopausal women with stage II breast cancer whose baseline fat intake was more than 30% of energy intake. The low-fat diet intervention protocol consisted of bi-weekly individual counseling sessions with emphasis on substitution of lower-fat foods for high-fat foods and maintenance of nutritional adequacy. Nutrient intakes were calculated from 4-day food records collected at baseline and after 3 months of diet intervention. Mean daily fat intake for the 17 patients on the low-fat diet dropped significantly from 38.4 +/- 4.3% of energy intake at baseline to 22.8 +/- 7.8% at 3 months (p less than .001). A 25% reduction in mean energy intake, from 1,840 +/- 419 kcal at baseline to 1,365 +/- 291 kcal at 3 months, was accompanied by significant increases in protein and carbohydrate as percent of energy intake. A mean weight loss of 2.8 kg and a 7.7% reduction in serum cholesterol were observed; both changes were significant at the p less than .01 level. Absolute intakes of zinc and magnesium were significantly reduced. However, mean intake on the low-fat diet for 14 vitamins and minerals, including zinc and magnesium, exceeded two-thirds of the 1989 Recommended Dietary Allowances (RDAs). When expressed as nutrient density (i.e., amount of nutrient per 1,000 kcal), increases were observed for all micronutrients. These results support the hypothesis that a nutritionally adequate low-fat diet can be successfully implemented in a highly motivated, free-living population.

Recommendations for the prevention of chronic disease: the application for breast disease.

Experimental and epidemiological evidence suggest that a diet with dietary fat as low as 20% of kcal may be necessary to reduce the risk of breast cancer. Two groups of women, postmenopausal women treated for breast cancer and premenopausal women with cystic breast disease accompanied by cyclical mastaligia, participated in an intervention program to determine the feasibility of such a low-fat diet. After 3 mo of intervention both groups were consuming a low-fat diet; in the premenopausal groups serum estrogen levels decreased in response to the fat reduction. Other nutrition-education programs in research institutions, restaurants, and schools are attempting to influence the public's knowledge and behavior regarding the importance of dietary fat reduction.

Diet, serum, breast fluid growth hormone, and prolactin levels in normal premenopausal Finnish and American women.

A food frequency questionnaire was used to estimate and compare the dietary fat and fiber consumption of 94 premenopausal women in Kuopio (rural Finland, where there is a relatively low risk of breast cancer) and 61 American women in New York (where there is a high risk of breast cancer). In keeping with previous reports concerning middle-aged men, both groups had high fat intakes, but the Finnish women had considerably higher fiber intakes (24 +/- 11 vs. 16 +/- 6 g). Serum and breast fluid growth hormone and prolactin levels were compared in 29 of these American women and 24 of the Finnish women. All were healthy and had regular menstrual cycles. Serum growth hormone levels, which were measured by radioimmunoassay, were higher in the Finnish women; all but three of their breast fluids contained detectable growth hormone, frequently at extremely high concentration. In contrast, only 2 of the 29 breast fluids from American women had detectable amounts of growth hormone. Of the Finnish samples, 10 were also measured by an immunoradiometric assay with high specificity for the 22,000-dalton growth hormone molecule; all but 3 had values less than 3.0 ng/ml. Serum and breast fluid prolactin concentrations, which were determined by radioimmunoassay, were no different in the two groups; both groups frequently had considerably higher levels in breast fluid compared with the corresponding serum.(ABSTRACT TRUNCATED AT 250 WORDS)

Response to a diet low in total fat in women with postmenopausal breast cancer: a pilot study.

A feasibility study was instituted to determine if women with postmenopausal breast cancer would follow a low-fat diet (20% of kcal) for at least four months. Nineteen women, whose baseline food intake was 1,504 +/- 420 kcal with 56 +/- 16 g of fat, reported a decrease in fat intake to 21 +/- 6 g after two months of dietary intervention. Serum concentrations of cholesterol, HDL cholesterol, and estradiol were significantly reduced by the fifth month on the diet. We conclude that self-selected patients can adhere to a low-fat diet, and that serum cholesterol may serve as an indicator of dietary compliance.

Effect of a low-fat diet on hormone levels in women with cystic breast disease. I. Serum steroids and gonadotropins.

For examination of the effect of a low-fat diet on serum estrogen, progesterone, and gonadotropin levels, 16 patients with cystic breast disease and cyclic mastalgia were studied before dietary intervention and at 2 and 3 months thereafter. Four-day food diaries indicated that total fat intake was reduced from a prediet average of 69 g (35% of total kilocalories/day) to an average of 32 g (21% of total kilocalories) after 3 months. Highly significant reductions (P less than .001) occurred in dietary cholesterol and less changes occurred in protein and total kilocalorie consumption (P less than .05); fiber intakes were not affected. After 3 months on this low-fat diet, there were significant reductions in luteal-phase serum total estrogens (P less than .001), estrone (P less than .005), and estradiol (P less than .01); progesterone, luteinizing hormone, and follicle-stimulating hormone levels were unchanged. Two of the 16 patients were excluded from the hormone statistical analyses because the serum progesterone levels were not consistent with sampling in the luteal phase of the menstrual cycle. It is concluded that a reduction of dietary fat intake to 20% of the total kilocalories will result in significant decreases in circulating estrogens in benign breast disease patients and that this effect is achievable without increasing dietary fiber consumption. Absence of changes in serum progesterone and gonadotropins during the dietary intervention is consistent with altered enterohepatic circulation of estrogens rather than with effects on the pituitary-ovarian axis.

Effect of a low-fat diet on hormone levels in women with cystic breast disease. II. Serum radioimmunoassayable prolactin and growth hormone and bioactive lactogenic hormones.

For investigation of the bioactivity of circulating prolactin and growth hormone (lactogenic hormones) in symptomatic benign breast disease, serum was assayed by the Nb2 lymphoma cell method in premenopausal patients with cystic breast disease and cyclic mastalgia and in normal premenopausal women. The results were compared with serum prolactin and growth hormone concentrations determined by radioimmunoassay. The serum bioassayable hormone levels in the benign breast disease patients (74.0 +/- 77.6 ng/ml) were significantly higher (P less than .001) than in normal women (23.8 +/- 10.7 ng/ml). There were no significant differences in the radioimmunoassayable prolactin or growth hormone levels between the 2 groups. When 16 cystic breast disease patients were placed on a low-fat (20% of total kilocalories) diet for 3 months, there were significant reductions in the serum bioassayable hormone levels (P less than .02). It is concluded that the bioactivity of prolactin may be elevated in the serum of patients with cystic breast disease and cyclic mastalgia, without corresponding increases in levels determined by radioimmunoassay; that this abnormality is reversible by a reduction in dietary fat consumption to 20% of the total kilocalories; and that serum prolactin may provide a valuable biomarker in clinical trials of a low-fat diet in women at high breast cancer risk.

International comparisons of mortality rates for cancer of the breast, ovary, prostate, and colon, and per capita food consumption.

The 1978-1979 mortality rates for cancers of the breast, prostate, ovary, and colon in 26 to 30 countries were related to the average 1979-1981 food availability data published by the United Nations. The previously described relationship between breast cancer mortality rates and animal fat consumption continues to be evident, and applies also to the other three tumor types. The correlation with breast cancer was particularly strong in postmenopausal women. Since 1964, particularly notable increases in both breast cancer mortality rate and dietary fat intake have occurred in those countries with a relatively low breast cancer risk. The international comparisons support evidence from animal experiments that diets in which olive oil is a major source of fat are associated with reduced breast cancer risk. The excess in mortality rates for breast and ovarian cancer in Israel relative to the national animal fat consumption may be due to the mixed ethnic origin of the Israeli population. Positive correlations between foods and cancer mortality rates were particularly strong in the case of meats and milk for breast cancer, milk for prostate and ovarian cancer, and meats for colon cancer. All four tumor types showed a negative correlation with cereal intake, which was particularly strong in the case of prostate and ovarian cancer. Although, in general, there was a good positive correlation between prostate and breast cancer mortality rates and between prostate cancer and animal fat, discrepancies in national ranking indicate the operation of other etiologic factors that modify risk. The observed positive correlations between the four cancer mortality rates and caloric intake from animal sources, but negative correlations for vegetable-derived calories, suggest that, of the two, animal fat and not energy is the major dietary influence on cancer risk.

The Fat Portion Exchange List: a tool for teaching and evaluating low-fat diets.

The Fat Portion Exchange System was developed as a tool for counseling clients on how to follow a diet low in total fat. The system incorporates the use of the Fat Portion Exchange List, which is an extensive list of foods with fat grouped according to food type. Listed is the amount of each food item that provides one fat portion (FP), or approximately 5 gm fat, as determined from food composition tables. The number of FPs to be eaten daily is prescribed according to the total daily caloric intake so that a diet with a specified percentage of calories from fat can be followed. The system emphasizes the tracking of only one nutrient--fat--which contributes to its simplicity, flexibility, and versatility.