Dietary Fat Consumption in a Cohort of American Adults, 1985–1991: Covariates, Secular Trends, and Compliance with Guidelines

Purpose. To examine compliance with the guideline for dietary fat (i.e., 30% of total daily calories) and covariates of fat intake in a cohort of adults using both 24-hour recall and food frequency questionnaire (FFQ). Design. Prospective, observational cohort study over 5 years. Setting. Community-based sample in Reno, Nevada. Subjects. Equal numbers of male and female, lean and overweight adults (n = 508), recruited from 1985 to 1986, of whom 348 completed all relevant surveys. Measures. Subjects underwent repeated anthropometric measures and completed extensive surveys on diet, weight cycling, lifestyle, and physical activity. Results. Mean fat intake by 24-hour recall declined from 36.9% to 33.6% of calories between years 1 and 5 (p < .001), while calorie intake increased (p = .2). As measured by FFQ at year 2, mean fat intake was 39.1 % of calories, and only 11.8% of subjects were in compliance with the guideline for dietary fat intake. Fat intake by FFQ at year 2 was statistically higher than by 24-hour recall in year 1 for lean women (p = .02) and lean men (p = .02), but not for the overweight of either gender, and was significantly higher than the year 5 24-hour recall for all categories of gender and weight (p < .001). Calorie intake, gender, and body mass index were significant in regression models that explained less than 10% of total variability in fat intake (r2 = .08; p < .01). Conclusions. Compliance with the nationally recommended level of dietary fat intake was poor in this cohort, especially as measured by FFQ. Variability in fat intake was largely unexplained by host characteristics, including education. Further study is required to corroborate secular trends in population fat intake, elucidate the determinants of such intake, and identify cost-effective strategies for reducing the consumption of dietary fat.