Fast food consumption of U.S. adults: impact on energy and nutrient intakes and overweight status.

OBJECTIVE: To compare the diet quality and overweight status of free-living adults, ages 20 years and older, grouped based on their fast food intake status.
METHODS: USDA's 1994 to 1996 Continuing Survey of Food Intakes by Individuals (CSFII 1994-1996) data was used. Three separate analyses were conducted: (1) effect of fast food on diet quality of males and females based on day-one data, (2) comparison of dietary and overweight status of adults who ate fast food on one- two- or none of survey days and (3) within-person analysis comparing energy and macronutrient intakes of adults who ate fast food on one of the two survey days. SUDAAN software package was used in pair-wise mean comparisons and regression analyses (alpha = 0.05).
RESULTS: At least one in four adults reported eating fast food. The diet of males and females who consumed fast food was high in energy and energy density. Fast food provided more than one-third of the day's energy, total fat and saturated fat; and was high in energy density. Negligible amounts of milk and fruits, but substantially large amounts of non-diet carbonated soft drinks were reported consumed at fast food places. After controlling for age, gender, socio-economic and demographic factors, energy and energy density increased and micronutrient density decreased with frequency of fast food consumption. Adults who reported eating fast food on at least one survey day had higher mean body mass index values than those who did not eat fast food on both survey days. A small, but significant, positive association was seen between fast food consumption and overweight status. Within-person comparisons showed that energy intakes were higher on a fast food day than on a non-fast food day.
CONCLUSION: Fast food consumption was associated with a diet high in energy and energy density and low in essential micronutrient density. Frequent fast food consumption may contribute to weight gain.