Study Versus Headlines at Breakfast

Most often, when the media mangles science, the blame goes to the health reporter. Reporters either misinterpret the research or don’t think critically about how PR is spinning the results. But this week, we have an exceptional case of a top-tier journal publishing conclusions to a study that the data simply do not support. The study is about thermogenesis at breakfast. No obesity, no measures of weight or adiposity. But authors draw a conclusion about obesity prevention – something for which the study provides no data whatsoever. So it’s no wonder that the breakfast headlines this week are misleading.

The headlines are all about how this research says a big breakfast is better for weight loss. The study appeared in the Journal of Clinical Endocrinology & Metabolism. It proves no such thing.

What the Study Actually Found

This was a lab study that compared the effects of breakfast on thermogenesis to the effects of dinner. It was a three-day, randomized, crossover design. The study enrolled 16 normal-weight men. The methodology is solid. It’s perfectly valid for its stated objective – to study thermogenesis.

But apart from making sure that none of the subjects had excess weight or obesity, the researchers did not study any measures of weight, adiposity, or obesity.

The results show that these men burned energy from breakfast faster than energy from dinner.  They also show that cutting calories at breakfast caused more hunger than cutting calories at dinner. But in their conclusions, the authors jump to the subject of obesity prevention, writing:

Extensive breakfasting should therefore be preferred over large dinner meals to prevent obesity.

They have no data to support that conclusion.

What We Know About Breakfast

Some people like breakfast and they’re hungry for it. Some people do not and are not. In general, studies have shown that pushing breakfast on people does not help with weight loss. In one study, pushing breakfast in the classroom actually led to an increase in obesity. Other studies have shown that people who are inclined to skip breakfast may actually have better weight outcomes if they do so.

Big Evening Meals Can Be a Problem

It’s also worth noting that big evening meals may lead to weight gain. Meal timing matters and lots of calories late in the day are generally a bad idea. The data from this present study might help to explain why that’s true.

However, none of this supports a conclusion that “extensive breakfasting” will prevent obesity. Prodding people to eat more can easily have just the opposite effect – promoting weight gain.

Science only has credibility when scientists stick to the facts and data.

Click here to read the study in JCEM.

Breakfast with Oatmeal, photograph © Ella Olsson / flickr. Find Olsson’s recipes here.

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February 21, 2020