Food patterns measured by factor analysis and anthropometric changes in adults
Sixty-five percent of US adults are overweight, and 31% of these adults are obese. Obesity results from weight gains over time; however, dietary determinants of weight gain remain controversial. Our objective was to examine whether food patterns derived from exploratory factor analysis are related to anthropometric changes. We hypothesized that we would derive a healthy food pattern and that it would predict smaller changes in body mass index (BMI; in kg/m(2)) and waist circumference (in cm) than would other food patterns in models adjusted for baseline anthropometric measures. The subjects were 459 healthy men and women participating in the Baltimore Longitudinal Study of Aging. Diet was assessed by using 7-d dietary records, from which 40 food groups were formed and entered into a factor analysis. Six food patterns were derived. Factor 1 (reduced-fat dairy products, fruit, and fiber) was most strongly associated with fiber (r = 0.39) and loaded heavily on reduced-fat dairy products, cereal, and fruit and loaded moderately on fruit juice, nonwhite bread, nuts and seeds, whole grains, and beans and legumes. In a multivariate-adjusted model in which the highest and lowest quintiles were compared, factor 1 was inversely associated with annual change in BMI (beta = -0.51; 95% CI: -0.82, -0.20; P < 0.05; P for trend < 0.01) in women and inversely associated with annual change in waist circumference (beta = -1.06 cm; 95% CI: -1.88, -0.24 cm; P < 0.05; P for trend = 0.04) in both sexes. Our results suggest that a pattern rich in reduced-fat dairy products and high-fiber foods may lead to smaller gains in BMI in women and smaller gains in waist circumference in both women and men.