Examining the interaction of fast-food outlet exposure and income on diet and obesity: evidence from 51,361 UK Biobank participants

• Published in: The international journal of behavioral nutrition and physical activity Vol. 15; no. 1; pp. 71 - 12
• Main Authors: Burgoine, Thomas, Sarkar, Chinmoy, Webster, Chris J, Monsivais, Pablo
• Format: Journal Article
• Language: English
• Published: England BioMed Central Ltd 24.07.2018; BioMed Central; BMC
• Subjects: Adipose Tissue; Adiposity; Biological Specimen Banks; Body fat; Body Mass Index; Body Weight; Cardiovascular disease; Cohort Studies; Consumption; Convenience foods; Cross-Sectional Studies; Diabetes; Diet; Economic aspects; Environment; Family income; Fast food industry; Fast Foods; Fast-food outlet exposure; Feeding Behavior; Female; Food habits; Health aspects; Health care; Health risk assessment; Household income; Households; Humans; Income; Interaction; London; Low income groups; Male; Meat; Meat Products - adverse effects; Medical research; Middle Aged; Nutrition research; Obesity; Obesity - economics; Obesity - etiology; Odds Ratio; Poverty; Processed meat consumption; Public health; Public health administration; Residence Characteristics; Restaurants; Retail stores; Risk factors; Socioeconomic factors; Systematic review; UK biobank; London; United Kingdom; United Kingdom > UK; Adiposity; Household income; UK biobank; Interaction; Fast-food outlet exposure; Processed meat consumption
• DOI: 10.1186/s12966-018-0699-8
• ISSN: 1479-5868

Household income (as a marker of socioeconomic position) and neighbourhood fast-food outlet exposure may be related to diet and body weight, which are key risk factors for non-communicable diseases. However, the research evidence is equivocal. Moreover, understanding the double burden of these factors is a matter of public health importance. The purpose of this study was to test associations of neighbourhood fast-food outlet exposure and household income, in relation to frequency of consumption of processed meat and multiple measures of adiposity, and to examine possible interactions. We employed an observational, cross-sectional study design. In a cohort of 51,361 adults aged 38-72 years in Greater London, UK, we jointly classified participants based on household income (£/year, four groups) and GIS-derived neighbourhood fast-food outlet proportion (counts of fast-food outlets as a percentage of all food outlets, quartiles). Multivariable regression models estimated main effects and interactions (additive and multiplicative) of household income and fast-food outlet proportion on odds of self-reported frequent processed meat consumption (> 1/week), measured BMI (kg/m ), body fat (%), and odds of obesity (BMI ≥ 30). Income and fast-food proportion were independently, systematically associated with BMI, body fat, obesity and frequent processed meat consumption. Odds of obesity were greater for lowest income participants compared to highest (OR = 1.54, 95% CI: 1.41, 1.69) and for those most-exposed to fast-food outlets compared to least-exposed (OR = 1.51, 95% CI: 1.40, 1.64). In jointly classified models, lowest income and highest fast-food outlet proportion in combination were associated with greater odds of obesity (OR = 2.43, 95% CI: 2.09, 2.84), with relative excess risk due to interaction (RERI = 0.03). Results were similar for frequent processed meat consumption models. There was no evidence of interaction on a multiplicative scale between fast-food outlet proportion and household income on each of BMI (P = 0.230), obesity (P = 0.054) and frequent processed meat consumption (P = 0.725). Our study demonstrated independent associations of neighbourhood fast-food outlet exposure and household income, in relation to diet and multiple objective measures of adiposity, in a large sample of UK adults. Moreover, we provide evidence of the double burden of low income and an unhealthy neighbourhood food environment, furthering our understanding of how these factors contribute jointly to social inequalities in health.