Away from home meals: associations with biomarkers of chronic disease and dietary intake in American adults, NHANES 2005-2010

BACKGROUND: Away from home (AFH) meals are known to be energy-dense and of poor diet quality. Both direct and indirect exposure (for example, neighborhood restaurant density) to AFH meals have been implicated as contributors to higher body weight and adverse health outcomes. OBJECTIVE: To examine the association of frequency of eating AFH and fast-food meals with biomarkers of chronic disease and dietary intake. DESIGN: This cross-sectional study used frequency of AFH and fast-food meal and biomarker data from the NHANES 2005-2010. Information on weekly frequency of AFH and fast-food meals was collected via questionnaire during the household interview. The metabolic biomarkers examined included body mass index (BMI), serum cholesterol (total, high-density lipoprotein (HDL) and low-density lipoprotein (LDL)), triglycerides, glycohemoglobin and fasting glucose (n = 8314, age >= 20, National Health and Nutrition Examination Surveys (NHANES) 2007-2010). Biomarkers of dietary exposure included serum concentrations of vitamins A, D, E, C, B-6, B-12, folate and carotenoids (n = 4162; 2005-2006). Multiple linear and logistic regression methods adjusted for complex survey methodology and covariates. RESULTS: American adults reported a mean of 3.9 (95% confidence interval 3.7, 4.0) AFH and 1.8 (1.6, 1.9) fast-food meals/week. Over 50% of adults reported >= 3 AFH and > 35% reported >= 2 fast-food meals/week. The mean BMI of more frequent AFH or fast-food meal reporters was higher (P-trend <= 0.0004). Serum concentrations of total, LDL and HDL-cholesterol were related inversely with frequency of AFH meals (P < 0.05). Frequencies of fast-food meals and serum HDL-cholesterol were also related inversely (P = 0.0001). Serum concentrations of all examined micronutrients (except vitamin A and lycopene) declined with increasing frequency of AFH meals (P < 0.05); women and >= 50-year olds were at higher risk. CONCLUSIONS: Reporters of frequent AFH and fast-food meals had higher BMI and lower concentrations of HDL-cholesterol; however, profiles of other biomarkers did not indicate higher metabolic risk. However, the serum concentrations of nutrients with mostly plant foods as sources declined with increasing AFH meal frequency.