ObesityWeek: Why Have We Failed to Reduce Obesity?

“I don’t have the answer, but I intend to be provocative.” With those words yesterday, Barbara Corkey opened her challenge to conventional thinking about obesity. After more than three decades, obesity prevalence keeps rising. Along with trend, diabetes rates are rising, too. Why have we so clearly failed to reduce obesity and diabetes?

Perhaps we have forgotten the difference between facts and hypotheses. If some of those hypotheses are false, then we have our facts wrong. And thus we build strategies and take action based on false information and wonder why it’s not working.

Eating Too Much

The most common assumption is that obesity is the result of eating too much. But in fact, said Corkey, the problem might not be how much we eat. Instead it might be that with obesity comes from a body’s failure to adjust to normal variations in the calories we consume. Under different circumstances, it’s quite clear that humans and other animals adjust their metabolic rate to cope with fluctuations in food availability. Birds burn seven times more energy when migrating than when not migrating. In hibernation, mammals cut their usual metabolic rate by three quarters.

The metabolic rate of naturally lean individuals can fluctuate, too.

In short, maybe the problem lies with what our bodies do with the calories we consume.

Insulin Resistance

Another supposed culprit is insulin resistance. The pathology of obesity and diabetes somehow makes our cells resistant to insulin. So the body makes more insulin. Then that sets off a series of metabolic problems and  the diseases get worse.

But in fact, there’s no evidence that insulin resistance is the cause of a body secreting too much insulin. Instead, said Corkey, it might be that insulin resistance is a protective response to too much insulin. We don’t have proof for what’s the cause and what’s the effect. All we have are hypotheses that need testing.

Inflammation

Typically, people think that inflammation is the result of obesity. But what if it’s the cause? Again, we have multiple hypotheses and no definitive answer, says Corkey. ROS – reactive oxygen species – can be an important signal of inflammation. Or it might have a causative role. We don’t have the answer. Just lots of questions and clues.

Too Much Insulin

If too much insulin is the problem at the root of obesity and diabetes, then we need to know what’s causing it. Perhaps it is the quality of our food. Or as many as 4,000 new chemicals that have entered our food supply. The animals that produce our meat have changed dramatically. Chickens are four times bigger now than they were in 1957. Even fruits and vegetables are different. But few of these changes get a close examination as potential causes for obesity.

The bottom line is this. If we want to reduce obesity, we need more objectivity about what’s causing the excess of it. So we need scientific curiosity driving us to find the truth. Assumptions are not good enough.

Click here for Corkey’s slides.

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November 8, 2019