From an outsider’s perspective, Morris said, the research on food insecurity and obesity has several prominent gaps that limit the ability to inform interventions. First, what are the relevant aspects of food insecurity that are central to the relationship? Is it the level of food insecurity, as measured by hunger or lack of food? Is it the quality of food that low-income individuals and families eat? Or is it the volatility of access to food that influences obesity?
Each of these factors points toward a different policy response. If the level of food insecurity matters, then families need more resources. If it is quality that matters, families need access to more nutritious food. If the critical factor is volatility, the question becomes how to smooth consumption over a monthly period so that families do not have times of great need and less need.
Gaps also exist in the research methods that can be applied to these topics, said Morris. In particular, better ways are needed to measure sources of influence across levels and causal processes.
Volatility may be the most understudied of these issues, Morris said. Volatility is also a topic that has not been much attended to in poverty research. In child development research, income is typically annualized so that short-term fluctuations are smoothed out (Duncan and Brooks-Gunn, 1997; Cancian and Danziger, 2009; Gennetian et al., 2010). Economics research has looked at earnings volatility; for example, earnings volatility has been linked with material hardship and food insecurity (Bania and Leete, 2007; Jolliffe and Ziliak, 2008; Mills and Amick, 2010). Yet poverty research generally has examined the volatility of residential stability or family structure (Wu and Martinson, 1993; Ackerman et al., 1999) and not income instability. Also, this research tends to look at a single event rather than a chronic pattern of events.
If a low-income family cannot predict its income levels, it may experience more distress than in adjusting to a routinely low income. Variations in how much parents can purchase for their children could have a variety of deleterious effects, from disruptions of predictable food cycles to reductions in academic achievement. Volatility could reduce parents’ time and money investments in children’s human development (Becker, 1981). Volatility also can lead to stress, raising the possibility that stress and not just deprivation leads to behavioral outcomes (McLoyd, 1990). In this regard, animal research has demonstrated enormous effects of unpredictable feeding and social relationships on parental and offspring behaviors.