The Institute of Medicine (IOM) invited public comments between October 14, 2010, and December 31, 2010, on Understanding the Relationship Between Food Insecurity and Obesity. Comments were submitted via the IOM website. The URL was shown during the workshop and sent via e-mail to workshop participants including speakers and to a list of experts working on food insecurity and/or obesity identified by the Planning Committee and the U.S. Department of Agriculture (USDA) Food and Nutrition Service. Three comments were received. The comments have been copy edited. The complete set of unedited comments was forwarded to the USDA Food and Nutrition Service for its consideration.
Inserm, Villejuif, Paris
Suggestions for future research:
There is need for evidence on long-term effects of food insecurity, ideally from birth cohort studies that follow individuals from childhood to adulthood.
Research should be conducted not only in low-income samples, but also in the general population, to gain a better understanding of factors that shape the risk of becoming food insecure.
Observational studies on the relationship between food insecurity and obesity should account for important factors that could play a
confounding role (income, socioeconomic position, race, psychological characteristics).
Greater use should be made of non-observational designs, which could help assess the causal nature of the association between food insecurity and obesity (quasi-experimental designs, natural experiments, reanalysis of randomized controlled trials that assess the effects of food supplementation).
Additional longitudinal research should examine the mechanisms through which food insecurity is associated with poor health—critical periods (which are the key developmental periods?), cumulative disadvantage, chains of risk.
Interventions and policies that aim to decrease hunger and food insecurity should be evaluated over the long-term, to test whether they contribute to improvements in health and decreases in health inequalities.
Johns Hopkins Bloomberg School of Public Health and
Global Health Policy Intern, PepsiCo
As a Johns Hopkins Bloomberg School of Public Health student and PepsiCo Global Health Policy intern in attendance at the Institute of Medicine Workshop on Food Insecurity and Obesity, I appreciated the presentations describing the current state of the research and the suggested solutions for food insecurity and obesity, but noticed the lack of discussion of several important factors. While several discussions focused on the negative contributions of food and beverage companies to overweight and obesity in low-income populations, conversation excluded the role of food companies as part of the solution. PepsiCo is taking important steps that should be noted:
Removing full-sugar sodas from primary and secondary schools by 2012 and encouraging schools to supply only products that meet nutrition guidelines set by the Alliance for a Healthier Generation;
Lowering sugar, salt, and fat in PepsiCo portfolio of products: sodium will be reduced 25 percent by 2015 in key global food brands; saturated fat will be reduced 15 percent by 2020 in key global food brands; and sugar will be reduced 25 percent by 2020 in key global beverage brands; and
Expanding the nutrition portfolio—including Quaker Oats, Tropicana, and Gatorade—from $10 billion to $30 billion in 2020, supported by the new Global Nutrition Group.
Further, an important issue overlooked by the panelists is the influence of federal farm subsidies on the price of foods. The low price of corn contributes to its common use as an ingredient in foods and beverages, while items that receive fewer federal subsidies, such as fruit and vegetables, are more expensive for both consumers and food companies, and therefore less commonly used in products. All actors, including food companies, must be involved as part of the solution to food insecurity and obesity, and better dialogue is needed between food companies, academia, and the public health community. PepsiCo is interested in partnering with these communities to improve the health of the population together.
Simmons College, Boston, Massachusetts
Comments on the association between food insecurity and obesity
The association between food insecurity and childhood overweight and obesity is a complex one that, as noted by the conference participants, requires more studies using a longitudinal design. On day 1 of this meeting, Craig Gundersen reviewed the evidence linking food insecurity and obesity in children, and he declared that there was no association. However, it should be noted that the evidence thus far is not conclusive one way or the other because the research is flawed; this was noted by many of the conference presenters. Specifically, most of the research on children, even in the reference cited by Gundersen in his conclusion, was based on studies that were cross-sectional in nature and did not specifically study low-income populations (Larson and Story, 2010). In fact, only four studies cited in this review were longitudinal in design (Jyoti et al., 2005; Rose and Bodor, 2006; Bhargava et al., 2007; Bronte-Tinkew et al., 2007). Two out of the four of these better-designed studies found either a direct or an indirect association between food insecurity and child weight gain or status (Jyoti et al., 2005; Bronte-Tinkew et al., 2007). Moreover, one study that was omitted from this review (Dubois et al., 2006), likely because of the fact that it examined food insufficiency instead of food insecurity, also had positive findings; that study (Dubois et al., 2006) also found that food insufficiency was associated with high weight status in children. This means that out of the five longitudinal studies in children, three found a direct (Jyoti et al., 2005; Dubois et al., 2006) or indirect association between (Bronte-Tinkew et al., 2007) food insecurity or insufficiency and either high weight gain or overweight and obesity in children.
A major limitation of even the large longitudinal studies is that samples were drawn from the general population rather than the low-income populations (where in fact food insecurity is a relevant and prevalent issue),
thus reducing the ability to detect associations between food insecurity and health outcomes given the low incidence of food insecurity among populations at higher income levels. In addition, most of these samples were not diverse enough to examine these associations within the racial/ethnic groups that experience food insecurity most acutely and chronically. The important point that I would like to make is that until we conduct well-designed studies (i.e., longitudinal studies with large samples of low-income children), we cannot derive any conclusions about the association between food insecurity and obesity in children. We need better-designed studies that examine longitudinally how food security status and changes affect birth outcome and early growth as well as the later risk of obesity; currently there is a paucity of such studies.
Bhargava, A., D. Jolliffe, and L. L. Howard. 2008. Socio-economic, behavioural and environmental factors predicted body weights and household food insecurity scores in the Early Childhood Longitudinal Study-Kindergarten. British Journal of Nutrition 100(2):438-444.
Bronte-Tinkew, J., M. Zaslow, R. Capps, and A. Horowitz. 2007 Food insecurity and overweight among infants and toddlers: New insights into a troubling linkage. Child Trends Research Brief. Washington, DC: Child Trends.
Dubois, L., A. Farmer, M. Girard, and M. Porcherie. 2006. Family food insufficiency is related to overweight among preschoolers. Social Science and Medicine 63(6):1503-1516.
Jyoti, D. F., E. A. Frongillo, and S. J. Jones. 2005. Food insecurity affects school children’s academic performance, weight gain, and social skills. Journal of Nutrition 135(12): 2831-2839.
Larson, N., and M. Story. 2010. Food insecurity and risk for obesity among children and families: Is there a relationship? A research synthesis. Princeton, NJ, and Minneapolis, MN: Robert Wood Johnson Foundation Healthy Eating Research.
Rose, D., and J. N. Bodor. 2006. Household food insecurity and overweight status in young school children: Results from the Early Childhood Longitudinal Study. Pediatrics 117(2): 464-473.