Food and Health: What We Assume and What We Know

The relationship between food and health is a complex and often subjective matter. The difference between what is widely assumed to be true and what is objectively known to be true can be very difficult to discern. It’s made harder by the tendency of people to stick with like-minded people on this subject — even in scholarly contexts.

You’ll find that tendency in a special issue of Health Affairs filled with interesting perspectives and data on the subject. The issue is heavy with opinion and analysis derived from uncontrolled observations and lighter on empiric evidence. A few authors and institutions are represented in multiple publications within the same issue. Inevitably, other institutions and scholars are unrepresented. One gets the sense of a bit of groupthink.

Regardless, this issue provides a clear picture of some things that we surely know:

1. Obesity is costly and complex. Claire Wang and colleagues give an excellent accounting for the high cost of the growing prevalence of severe obesity and suggests that “access to cost-effective treatment for severe obesity should be part of each state’s strategy to mitigate rising obesity-related health care costs.”
    
2. Food insecurity undermines health. Craig Gundersen and James Ziliak provide a detailed survey of the literature on the health consequence of food insecurity.
    
3. Americans are preparing less of the food they eat. An unmistakeable trend away from home food preparation has enormous implications for how we obtain and consume food. Prepared food and restaurant food have a growing impact on dietary health.

 
Yet some assumptions are presented as fact when the reality is much fuzzier.

1. Obesity is a foodborne illness. Editor Alan Weil introduces this issue by stating that “our eating habits are leading to obesity.”  The reality is much more complex, with a long list of factors that are contributing to the excess of obesity, as you can see in this infographic.
    
2. American diets are becoming healthier. Analyses of changing dietary patterns and their effect on health in America are inherently problematic. They are based on self-reported dietary behaviors known to be scientifically unreliable. Perhaps people are reporting healthier diets because we are bombarding them with education urging them to do so.
    
3. Better dietary information brings better choices. Woven through this issue is commentary that assumes people will make better dietary choices if they have better information. Extensive experience with consumer behavior suggests that this is a shaky assumption at best. Restaurant menu labeling is a case in point.

 
The interaction of consumer behaviors, food, and health are complex and often counterintuitive. Groupthink will not serve us well in policymaking. We need more diversity of thought on the subject, more reliance on objective evidence, and more give and take among diverse stakeholders.

Click here to dive into this special issue of Health Affairs.

Turnip the Radish, photograph © J V Tran / flickr

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November 16, 2015