Abstract 15558: Increases in Dietary Fat Intake among the Framingham Heart Study Participants: Trends from 1991-2008

Abstract

Introduction: Few longitudinal studies among US adults have evaluated long-term dietary intakes and whether national recommendations for macronutrient intake are met. The objective of this study was to examine trends in dietary fat intake and food sources of fat in the longitudinal Framingham Heart Study (FHS) Offspring Cohort. Hypothesis: We hypothesized that dietary fat intake changed over time in response to national recommendations to consume a low-fat diet to reduce cardiovascular disease risk.

Methods: The FHS Offspring Cohort began in 1971-75 with follow-up exams every 4 years. Comprehensive dietary data were collected via the Harvard semi-quantitative food frequency questionnaire (FFQ) beginning in 1991 (Exam 5). We included 2,732 adults ages 20+ with complete data at Exam 5 and who attended at least 2 follow-up exams. Descriptive statistics were generated and mixed effects linear regression was used to examine trends in macronutrient and food intake over the 17-year follow-up period using SAS 9.3.

Results: The mean age of adults at Exam 5 was 54.1 years. Body weight, BMI, and the percentage of obese and insulin resistant adults increased from 1991-2008 (p<0.0005). No change was observed in total energy intake over time (p=0.48). The percentage of calories (%kcal) from total fat and protein increased (+2.5% and +2.1%, respectively) and %kcal from carbohydrate decreased (-4.2%) (p<0.0005). Increases were seen in %kcal from animal (+1.2%), vegetable (+1.7%), polyunsaturated (+0.4%), monounsaturated (+1.3%), saturated (+0.7%), and omega-3 fats (+0.04%), while %kcal from trans-fat decreased (-0.3%)(p<0.0005). The number of weekly servings of cheese, eggs, ice cream desserts, and nuts increased, but intake of milk, margarine, chips, and breads decreased over time (p<0.0005). These associations remained consistent when analyses were stratified by sex and BMI categories, although some differences in food intake by BMI category were observed.

Conclusions: Fat intake (measured as %kcal) increased over time, but remained within the Acceptable Macronutrient Distribution Range. These results suggest that national recommendations to reduce fat intake may not have influenced dietary behavior in this predominately white, older adult cohort.