Fast-food consumption, diet quality and body weight: cross-sectional and prospective associations in a community sample of working adults

OBJECTIVE: To examine the association between fast-food consumption, diet quality and body weight in a community sample of working adults. DESIGN: Cross-sectional and prospective analysis of anthropometric, survey and dietary data from adults recruited to participate in a worksite nutrition intervention. Participants self-reported frequency of fast-food consumption per week. Nutrient intakes and diet quality, using the Healthy Eating Index-2010 (HEI-2010), were computed from dietary recalls collected at baseline and 6 months. SETTING: Metropolitan medical complex, Minneapolis, MN, USA. SUBJECTS: Two hundred adults, aged 18-60 years. RESULTS: Cross-sectionally, fast-food consumption was significantly associated with higher daily total energy intake (β=72·5, P=0·005), empty calories (β=0·40, P=0·006) and BMI (β=0·73, P=0·011), and lower HEI-2010 score (β=-1·23, P=0·012), total vegetables (β=-0·14, P=0·004), whole grains (β=-0·39, P=0·005), fibre (β=-0·83, P=0·002), Mg (β=-6·99, P=0·019) and K (β=-57·5, P=0·016). Over 6 months, change in fast-food consumption was not significantly associated with changes in energy intake or BMI, but was significantly inversely associated with total intake of vegetables (β=-0·14, P=0·034). CONCLUSIONS: Frequency of fast-food consumption was significantly associated with higher energy intake and poorer diet quality cross-sectionally. Six-month change in fast-food intake was small, and not significantly associated with overall diet quality or BMI.