Tuesday, November 18, 2014

U.S. food supply inconsistent with dietary guidance

The U.S. food supply is far out of balance with dietary recommendations. A new study in the Journal of the Academy of Nutrition and Dietetics quantifies the gaps. In brief, the U.S. food supply was quite unhealthy already by the 1970s and has not improved noticeably since then.

The authors -- Paige Miller, Jill Reedy, Sharon Kirkpatrick, and Susan Krebs-Smith -- use a measure more commonly applied to individual survey data, called the Healthy Eating Index. Getting this measure to fit national food supply data from USDA requires a bit of shoe-horning, but nonetheless the results are persuasive about the basic picture. As the video below illustrates, for example, Americans have for decades had all the protein we could possibly need, but the food supply for vegetables falls much short of recommendations.

The video -- from the National Collaborative on Childhood Obesity Research (NCCOR) -- generally thinks of the food supply as "upstream" and food consumers as "downstream." A possible implication is that policies should alter the food supply so that downstream consumers could eat more healthfully. It should be noted that people in the food business, and perhaps most agricultural economists too, give greater weight to consumer preferences for unhealthy food as a key driver of the gap the study describes. Economists may suggest that the food supply would provide plenty of healthy food if that's what consumers actually would buy.

Still, nutrition scientists and agricultural economists have in recent years been doing better than ever at listening to each other's perspectives on these big questions. For example, in an accompanying article, which calls on dietitians to get involved in designing federal policies such as the Farm Bill, Claire Zizza reviews agricultural economics perspectives as well as public health perspectives on how such policies should be evaluated. It all makes a lively conversation.


1 comment:

Britta Moore said...

What a fascinating way to examine the American food environment. I wonder if part of the reason for the discrepancy between food supply and guidelines would be the perishable nature of fresh produce, as this may limit its availability to curb waste. Perhaps the less nutritious foods are found in greater abundance because they can remain on shelves for a longer time prior to purchase. It would be interesting to somehow examine the turnover of food at grocery stores to see if food purchases, rather than just food supply, show a similar discord with dietary guidelines. Then again, studies applying HEI scores to dietary intake definitely support the over-consumption of minimally nutritious foods.