The relation between dietary change and rising US obesity

OBJECTIVE: To determine if the source from which food is obtained has contr ibuted to the increased obesity of the US population, while controlling for demographic, lifestyle and regional factors. METHODS: Multiple regression was used to estimate the effect of food source on body mass index (BMI) while accounting for other factors which have bee n shown to affect obesity in a nationally representative sample of the US p opulation. SAMPLE: This study used secondary data from the 1994 - 1996 Continuing Surv ey of Food Intake by Individuals (CSFII). The CSFII is a nationally represe ntative sample of 16,103 individuals, obtaining for each respondent 24 h re calls of all food intake on two nonconsecutive days as well as demographics and information on lifestyle choices. RESULTS: For a large number of demographic and lifestyle factors, our resul ts support those which have previously been found to contribute to increase d overweight. Our contribution is to examine whether the source from which food is obtained also contributes to increased overweight. Our evidence sug gests that this is the case. The average height for males in our sample was 1.77 m. For two such males, one who ate food away from home (FAFH) during the previous 24 h period and the other who did not, results suggest that th e first will be about 1 kg heavier, all other factors being equal. For two females of average height (1.63 m) the same is true for those who ate fast food, but not at restaurants. In all cases, except females who ate at resta urants, the effects are significant in the regression (P < 0.05). CONCLUSION: The trends in both increased US obesity and in increased consum ption of FAFH are unlikely to be coincidental. FAFH, and particularly fast food consumption, are likely to be contributing factors to increased obesit y.