Relative validity of a food frequency questionnaire among tin miners in China: 1992/93 and 1995/96 diet validation studies.

Objective: Diet validation research was conducted to compare the respondents' reporting of dietary intake in a food frequency questionnaire (FFQ) with intake reported in food recalls. Because the population received annual salary increments that could modify food intake, diet validation studies (DVSs) were conducted during two time intervals.

Design: A 99-item FFQ was administered by an interviewer twice in a 1-year interval, and responses to each FFQ item were compared with 28 days of interviewer-administered food recalls that were collected in four 1-week intervals during each season of 1992/93.

Intake of vitamins E, C, and A and risk of lung cancer. The NHANES I epidemiologic followup study. First National Health and Nutrition Examination Survey.

The relation between the dietary intake of vitamins E, C, and A (estimated by a 24-hour recall) and lung cancer incidence was examined in the First National Health and Nutrition Examination Survey Epidemiologic Followup Study cohort of 3,968 men and 6,100 women, aged 25-74 years. During a median follow-up period of 19 years (from 1971-1975 to 1992), 248 persons developed lung cancer. Adjusted for potential confounders using Cox proportional hazards regression methods with age as the underlying time variable, the relative risk of lung cancer for subjects in the highest quartile of vitamin C intake compared with those in the lowest quartile was 0.

Dietary intake of fat, fiber and other nutrients is related to the use of vitamin and mineral supplements in the United States: the 1992 National Health Interview Survey.

Supplement intake is hypothesized to increase the risk of some diseases while decreasing the risk of others. Both diet and lifestyle behaviors, however, may be associated with supplement use and confound observed associations. Nutrient intake from a food frequency questionnaire, demographic characteristics and lifestyle among supplement users and nonusers were examined in 11,643 adults who participated in the 1992 National Health Interview Survey Epidemiology Supplement.

Lipid levels in adults with cystic fibrosis.

Objective: To examine the hypothesis that an energy-dense, high-fat diet, which is necessary to maintain weight in adults with cystic fibrosis, does not result in high serum cholesterol levels.

Design: Dietary, anthropometric, and biochemical data were correlated.

Setting: A cystic fibrosis center in Pittsburgh, Pa.