Food insecurity appears to be related to weight gain in women. Researchers had already noticed that women in food insecure households were more likely to be overweight. The new contribution in a study by Jerusha Peterman and myself, recently in the Journal of Nutrition, is to use nationally representative data to measure the change in weight over the same 12 month period for which food security status is measured.
We found that women in fully food secure households had a comparatively low probability of gaining 10 lbs or more during the year, and women with intermediate levels of food insecurity (such as "food insecurity without hunger") had the highest frequency of gaining 10 lbs or more. Women with the most serious evidence of food insecurity with hunger were back to having a comparatively low risk of gaining 10 lbs or more.
What could be going on? Perhaps an involuntary "boom and bust" food cycle due to food insecurity tricks the body's metabolism into retaining calories when they are available. Or perhaps the same resource cycle simply provokes people to eat bad inexpensive food when resources are scarce. Or perhaps both food insecurity and weight gain were caused by some other factor, which we were not sufficiently clever to measure. Because it looks at weight change, rather than just cross-sectional comparisons across people, the study increases the circumstantial evidence that food insecurity leads to weight gain, but it still falls short of proving causation.
We don't know why the same pattern didn't show up for men.
I got interested in this topic after studying the "food stamp cycle" in my dissertation and later research some years ago. It turns out that a large fraction of people's benefits are spent in the first few days after they are received. I think it would be worthwhile to study policy options such as delivering benefits twice monthly, to see if this approach improves the program's effectiveness in promoting both food security and good nutrition, without deterring participation by imposing undue hardship on program participants.
This research also may call into question whether "losing weight" should be one of the 18 items on the federal government's official food security survey. It happens that USDA's Economic Research Service is currently seeking public comment about the content of that survey, with a deadline of June 16 for comment submission (.pdf). I will share my thoughts in a future post, in addition to sending the comments to ERS, but if you are thinking of sending comments, see first the recent National Academies report on the topic for a bunch of context.
The Journal of Nutrition paper has received a good deal of press in the past few days. My school's public relations office described the article in a "policy point." The research was summarized in a brief by Sena Desai Gopal in the Boston Globe (scroll past the first article here) and an article by Amy Norton on Reuters.
Jerusha is giving a brief presentation of the paper at the annual meeting of the American Agricultural Economics Association (AAEA), as part of a "track" of sessions sponsored by the Food Safety and Nutrition Section, on Monday July 24 in Long Beach, CA. The session (.pdf), which includes other papers on food security measurement, including a briefing about the National Academies Report, is titled, "Hunger in America: A moment of reflection on U.S. food security measurement."