Mixing Up Correlation, Causation, Obesity, and Poverty

It’s an easy mistake to make. “It’s poverty, not individual choice that is driving extraordinary obesity levels,” writes Martin Cohen in The Conversation. That seems like a reasonable sentiment. But it’s not quite true.

A Messy Correlation

The truth is that poverty can predict a higher risk of obesity – in some cases. But not all. The Food Research and Action Center calls out the myth. Poverty does not cause a uniformly higher risk of obesity. The myth overlooks two key facts says FRAC:

1. The relationship between income and weight can vary by gender, race-ethnicity, or age.

2. Disparities by income have been weakening with time, particularly for adults.

The relationship between income and obesity involves an interaction among many factors. For white women, the link between obesity and low economic status is more consistent. But for black men, the relationship is the opposite. Higher income links to a higher obesity prevalence.

Using Bias to Drive Policy

Because this myth connects two stigmatized conditions – poverty and obesity – it can be very seductive. Poor people make bad choices. People with obesity make bad choices. They must have a connection. Bad policymaking flows from those bad assumptions.

Tamar Haspel describes how this thinking plays out:

It’s a conversation I’ve had many, many times. Invariably someone suggests that we have to fight obesity by fighting poverty. Increase the minimum wage, ensure decent housing, provide medical care. If we lift people out of poverty, the obesity problem will ease.

From that kind of thinking, we get policies that don’t work. For example, USDA spent hundreds of millions of dollars fighting food deserts during the Obama administration. Obesity rates were higher in poor neighborhoods. Those neighborhoods were usually food deserts. They lacked markets selling fresh, wholesome foods. So why not invest to clean up those food deserts? Surely this will fight obesity. At least, that was the rationale.

But as it turned out, this effort made no difference. Demand, not supply, is the key to healthier dietary patterns.

More Complete Strategies

Bottom line, we should remember that obesity has both biological and social dimensions. Genes and physiology drive obesity. Our environment – food, activity, and stressors – drove the epidemic. And now, the epidemic is entrenched. It is pandemic. The disease affects 40 percent of American adults. The rest of the world is catching up.

Social prescriptions alone are not enough. Simply fighting poverty and preaching about healthy lifestyles won’t reduce obesity’s impact. Yes, efforts to reduce the factors promoting obesity will help – if they’re backed by real evidence.

But better medical care for people living with obesity must also be part of the plan. For a condition that affects nearly half the population, progress will be impossible otherwise.

Click here for more from Tamar Haspel in the Washington Post and here for more from FRAC. For perspective from CDC researchers, click here and here.

Girl in Hormozgan, photograph © UNICEF Iran, Shehzad Noorani / flickr

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August 15, 2018