Lifestyle Instability: The Real Cause of American Obesity?

By Ross Pomeroy | April 25, 2025 | 11:37am

Photo by Jon Tyson/Upsplash

Healthcare Health Care

Lifestyle Instability: The Real Cause of American Obesity?

Americans are overweight and out of shape. We all have read or heard the statistics a bajillion times. While the scope of the problem is evident, the causes are not. Conventional thinking, born out of epidemiological and physiological evidence, suggests that we’re putting on excess pounds gradually via continuous energy imbalance, consuming more calories than we burn. Maybe this is due to our heavily processed diet chock full of fat and sugars? Maybe it’s our culture of eating outside the home? Maybe, according to our HHS Secretary Robert F. Kennedy, Jr., it’s all those pesky seed oils and pasteurized milk? (Yeah, it’s definitely not those…)

Earlier this month, a team of sports and exercise scientists based out of the UK put forth a novel explanation for elevated obesity based on emerging scientific data. New techniques allowing for a more granular view of weight gain suggest that people tend to pack on pounds in infrequent bursts rather than steadily over sustained periods of time. Triggering these rapid bouts of weight gain are temporary lifestyle disruptions.

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These lifestyle disruptions could be innocuous – holidays, vacations, moving, the birth of a child, starting college. When knocked out of our regular dietary habits, we tend to overeat, and those excess calories get stored as fat. As an example, the researchers noted that at Christmastime, people can consume as many as 6,000 calories per day, roughly the same amount eaten by Tour de France cyclists. But disruptions can also be negative and more destabilizing, like sudden financial hardship, job loss, injury, and illness. Despite recent inflation, food – particularly calorically dense, ready-to-eat, processed food – remains cheap and plentiful in America. We often turn to this unhealthy bounty in uncertain times.

“The magnitude of body fat gain provoked by these events may fully account for annual body fat gain,” the authors wrote.

Correlational evidence abounds to support their theory. Americans’ financial fragility has worsened in step with rising obesity. Moreover, our waistlines explosively expanded in the quarter-century after 1980, a time when wealth inequality similarly ballooned. A study from Johns Hopkins public health researchers published last fall revealed that U.S. counties with higher minimum wages had lower rates of obesity.

Looking at Americans’ collective weight problem through the lens of “lifestyle instability,” it’s easy to see why we have far higher rates of obesity than denizens of the European Union. Americans are much more susceptible to harmful lifestyle disruptions than Europeans. In 2023, the EU spent significantly more on social protection as a percentage of GDP than the U.S.: 26.9 percent compared to 18.7 percent, cushioning their citizens against life’s blows. Far greater proportions of Europeans have adequate healthcare. Europeans are less likely to be injured in the workplace. They’re three times less likely to be severely hurt in a motor vehicle.

Obesity is a multifaceted problem, so ameliorating lifestyle instability alone won’t solve it. But it does provide a new way to look at the problem, and brings to the fore new potential remedies – such as strengthening safety nets, reducing inequality, and enhancing workplace and public safety.

The authors say there are two key implications for public health if their theory is valid.

“First, if lifestyle disruptors are the main driver of annual fat gain, prevention strategies should focus on these events. Second, if fat gain occurs in short episodes, effective interventions may only require infrequent temporary behavioural changes.”