Dietary patterns associated with metabolic syndrome, sociodemographic and lifestyle factors in young adults: the Bogalusa Heart Study.

Studies involving dietary patterns (DP) and their association with diseases have several benefits over the conventional approach, which has focused largely on the effects of single nutrients or individual foods(1,2). As the measurement of diet is complex, and foods are typically consumed in combinations, the combined effect of nutrients and foods can be observed only when DP are examined(1,2). Moreover, results from DP analyses are more helpful in disseminating diet-related messages to consumers that they may be more likely to adhere to rather than those related to single foods or nutrients(3). DP have also been related to selected biomarkers of dietary exposure(1,2) and have been reported to contribute in the development or prevention of CHD and type 2 diabetes mellitus (T2DM)(4). Recent focus has been on the occurrence of metabolic syndrome (MetS), a constellation of metabolic abnormalities including central obesity, elevated blood levels of CHD-promoting lipids, hypertension, insulin resistance and hyperglycaemia(5). In adults, MetS increases the risk of CHD by two-fold and the risk for T2DM by five-fold(5–7). The age-adjusted prevalence of MetS in US adults (≥20 years) participating in the 2003–2006(8) National Health and Nutrition Examination Survey (NHANES) was 34 % v. 29·2 % reported in the 1988–1994 NHANES(9). Among young adults (20–39 years), the prevalence of MetS has increased from 10·8 % (in 1988–1994)(9) to 15·6 % (in 2003–2006) in females(8), and from 15·7 % (in 1988–1994)(9) to 20·3 % (in 2003–2006)(8) in males. Young adulthood is an important period of transition from adolescence into adulthood, when individuals begin to live an independent life. Pressures of independence, hurried lifestyles and providing support for new families may lead to shifts in their dietary and lifestyle patterns. Consequently, unhealthy dietary habits such as skipping breakfast(10), relying on fast food(11) and eating outside home(12) are prevalent among young adults. Moreover, individuals from rural and semi-rural US communities tend to have poorer dietary and health habits because of their lower socio-economic status (SES)(13–15). It is therefore critical to examine the DP of young adults and their relation to risk factors for chronic diseases in order to administer effective dietary and lifestyle prevention and treatment programmes for metabolic disorders such as the MetS, in this age group. Despite the rising prevalence of MetS, few recent studies have examined the role of DP and their relationship with MetS(16–20); their results, in general, showed that healthy DP were inversely associated with the occurrence of MetS in adults(16–20). However, to date only one Bogalusa Heart Study (BHS)(21) has examined the relationship of diet with MetS in young adults, and showed that lower fruit and vegetable consumption and higher sweetened beverage consumption were independently associated with one to two risk factors for MetS(21). Yet, the above-mentioned BHS explored the association of only single food groups rather than DP with MetS. The present study, although an extension of the previous BHS(21), had two additional objectives. First, it aimed to identify various DP among young adults and to examine the association of these DP with the risk factors of MetS. Second, because food consumption differs by SES and demographic factors such as gender and ethnicity(13), and the occurrence of MetS is related to lifestyle factors such as physical inactivity, smoking and alcohol consumption(22), the present study also assessed SES, and demographic and lifestyle differences among the DP in these young adults.