Although most obesity experts (including myself) will extoll the wisdom of starting each day with a nutritious breakfast, evidence on whether or not skipping breakfast actually promotes obesity (or having breakfast prevents it) is perhaps less cut and dried than we may want to believe.
This issue is extensively discussed as a “case study” by Andrew Brown and colleagues from the University of Alabama on how evidence for or against a popular “belief” may be misconstrued even by researchers who should know better.
The paper, published in the American Journal of Nutrition uses the example of the proposed effect of breakfast on obesity (PEBO) to examine how commonly researchers misconstrue data using one or more of the following unscientific practices: 1) biased interpretation of one’s own results, 2) improper use of causal language in describing one’s own results, 3) misleadingly citing others’ results, and 4) improper use of causal language in citing others’ work.
As the authors nicely dissect in their article, the PEBO literature is widely affected by the various forms of misinterpretation and misrerporting (often in favour of a breakfast benefit).
The authors also present on how a strong belief (e.g. in the benefits of having breakfast) can lead to a self-perpetuating cycle of research reporting that appears to support this belief.
This is certainly not a phenomenon limited to the effects of breakfast or to nutrition research in general. Rather, I would not be surprised if this practice is far more widespread than we would assume, leading us to often believe that some things are scientifically well established when the actual evidence is far less robust than we might think.
Incidentally, in the case of breakfast eating, there is indeed a large amount of epidemiological data showing less obesity in people who eat breakfast – this however cannot be interpreted to show that eating breakfast prevents obesity or promotes weight loss – that would be assuming causality, which is simply not possible to deduce from such studies.
Indeed, the highest quality data from the few randomised controlled trials on this issue (n=8), ranging in duration from 1 week to 3 school years are largely inconsistent, with one study even suggesting that whether eating or skipping breakfast is more effective for weight loss may depend on the individual’s typical breakfast habits.
So, although I would still maintain that regularly eating a nutritious breakfast may be the best way to start a day, whether or not this will help avoid or better manage your weight is likely to very much vary between individuals.
If you have personal experience with how eating breakfast has affected your diet (or weight), I’d certainly like to hear about it.
Brown AW, Bohan Brown MM, & Allison DB (2013). Belief beyond the evidence: using the proposed effect of breakfast on obesity to show 2 practices that distort scientific evidence. The American journal of clinical nutrition PMID: 24004890