Discussion
In young adult black and white men and women living
in the USA between 1985–86 and 2000–01, we recorded
strong positive associations between frequency of visits
to fast-food restaurants and increases in bodyweight and
insulin resistance, the two major risk factors for type 2
diabetes.
By comparison with the average 15-year
weight gain in participants with infrequent fast-food
restaurant use at year 0 and follow-up, those with
frequent fast-food restaurant use at both baseline and
follow-up gained an extra 4·5 kg bodyweight and had a
two-fold greater increase in insulin resistance. The
associations seemed to be largely independent of other potentially confounding lifestyle factors, such as physical activity and television viewing.Our findings accord with those of cross-sectional and shorter prospective studies of fast food and body weight. Binkley and colleagues reported that fast-food consumption was independently associated with body weight in a cross-sectional analysis of 16 103 adults.French and co-workers reported that intake of fried potatoes predicted 2-year weight gain in women but not men. In a 3-year prospective observational analysis of 891 women participating in a weight loss study, fast-food restaurant use was directly associated with bodyweight.