Household-level financial uncertainty could be the primary driver of the global obesity epidemic.

Evidence has accumulated in support of the notion that changes in household-level financial uncertainty (or "economic insecurity") may be an important fundamental cause of the global obesity epidemic. The timing and spatial/demographic incidence of the obesity epidemic suggest that economic policies aimed at expanding economic freedom may have inadvertently shifted risk to households, thereby generating a costly public health problem.

Smart food policies for obesity prevention.

Prevention of obesity requires policies that work. In this Series paper, we propose a new way to understand how food policies could be made to work more effectively for obesity prevention. Our approach draws on evidence from a range of disciplines (psychology, economics, and public health nutrition) to develop a theory of change to understand how food policies work. We focus on one of the key determinants of obesity: diet. The evidence we review suggests that the interaction between human food preferences and the environment in which those preferences are learned, expressed, and reassessed has a central role. We identify four mechanisms through which food policies can affect diet: providing an enabling environment for learning of healthy preferences, overcoming barriers to the expression of healthy preferences, encouraging people to reassess existing unhealthy preferences at the point-of-purchase, and stimulating a food-systems response. We explore how actions in three specific policy areas (school settings, economic instruments, and nutrition labelling) work through these mechanisms, and draw implications for more effective policy design. We find that effective food-policy actions are those that lead to positive changes to food, social, and information environments and the systems that underpin them. Effective food-policy actions are tailored to the preference, behavioural, socioeconomic, and demographic characteristics of the people they seek to support, are designed to work through the mechanisms through which they have greatest effect, and are implemented as part of a combination of mutually reinforcing actions. Moving forward, priorities should include comprehensive policy actions that create an enabling environment for infants and children to learn healthy food preferences and targeted actions that enable disadvantaged populations to overcome barriers to meeting healthy preferences. Policy assessments should be carefully designed on the basis of a theory of change, using indicators of progress along the various pathways towards the long-term goal of reducing obesity rates.

Effects of household composition and income security on body weight in working-age men.

OBJECTIVE: Many recent studies have provided evidence suggesting that increases in body weight may spread via social networks. The mechanism(s) by which this might occur have become the subject of much speculation, but to date little direct evidence has been available. Building on evidence from economics, anthropology, and behavioral biology, within-household peers might influence body weight via implicit provision of income security was hypothesized. DESIGN AND METHODS: Using a sample of 2,541 working-age men from the National Longitudinal Survey of Youth (1979), the effect of cohabitation on weight gain over a 6-year period was estimated. The potential confound caused by the joint determination of economic insecurity and cohabitation status with instrumental variables that exploit variation in local and state-level macroeconomic conditions and the presence of children in the home was addressed. RESULTS: The marginal effect of cohabitation with adults on body weight is negative. Moreover, the magnitude of the effect is more than six times greater when the cohabitant is engaged in paid employment. CONCLUSIONS: Income insecurity may play an important role in peer-to-peer transmission of weight gain.