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Nothing Cut And Dried About Eating Breakfast

sharma-obesity-breakfastAlthough 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.

Edmonton, Alberta

ResearchBlogging.orgBrown 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




  1. I’ve often wondered whether the breakfast issue is one of leaving a food environment you can control at home and stepping out into a dysfunctional food environment. I’m guessing most people who skip breakfast get pretty hungry mid-morning. If you skip, and you’re ravenous and stuck at the office, your options may be donuts or whatever’s in the vending machine down the hall. So it’s not so much that there’s something magical about eating at a specific time, but more of what your options are at different times of the day.

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  2. From my experience I would say it has more to do with what you eat at breakfast than if you eat it. For instance if I eat a carb heavy one I am very hungry 2 hours later, if I eat one of protein and fat I usually don’t eat again until 2 or 3 in the afternoon. After that, small lo-carb meals satisfy for the rest of the day.

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  3. Dr Sharma, perhaps my best years for weight-loss over the decades have come via a strategy of eating nothing until lunchtime. The basic idea was that eating first thing tends to “open the floodgates” to eating from dawn to dusk and beyond. Of course, whatever strategy helps one eat less 24/7 week in week out probably will be helpful in weight control.

    What I’ve found in the past two years is that avoiding all processed foods – particularly all sugary foods and drinks – assists “appetite control” in a way that didn’t happen when the sweet stuff featured of my diet. If I’m eating sugary stuff, I’m generally eating everything in sight, morning, noon and night.

    These days, I find that if I stick to whole-foods like meat, fish, eggs, cheese, nuts, fresh veges and fruit, then I generally feel satiated most of the time.

    My sense now is that it matters much more WHAT we eat than WHEN we eat it. In particular, a calorie is not a calorie: sugary foods for many are a disaster for appetite control.

    My weight has been flat at a healthier level for nearly two years now, almost as long as I have been encouraging the University of Sydney to correct or retract its “shonky sugar study”:

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  4. I find it interesting when long-standing dietary beliefs are put to the test by scientific liturature. There are two other nutrition beliefs that have wide-spread popularity but I have not been able to find any real scientific evidence to support them.

    The beliefs I am referring to are: 1. eating your daily calorie requirements later in the day and into the evening will cause weight gain, and 2. significantly lowering your caloric intake will slow your metabolism and can actually cause weight gain.

    I dont think I have ever seen any study done to suggest these beliefs are true. If anyone knows of any, please let me know. Thanks

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  5. Dr. Sharma,
    I have been a research subject in a study of the effect of exercise on BMR among other outcomes. I was an outlier, BMR decreased with exercise regime (faithfully followed). The opposite to other participants.
    I am a night owl and seldom hungry first thing in the morning.
    Two points: we are not all the same. Maybe 1st thing breakfast works for some and not for others
    Second, perhaps we can define breakfast as the first meal, not necessarily an early morning one.

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  6. Here’s a better interpretation of the correlations.

    1. People eat when hungry
    2. Slim people tend to be more hungry in the morning and so are more likely to eat breakfast
    3. obese people tend not to be hungry in the morning and so are more likely to skip breakfast.

    It could also be said that slim people are more likely to wear small clothes so therefore wearing small clothes is what keeps them thin.

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  7. The other wide spread belief that has been discounted, but still persists is that the BMI can diagnose illness. The furor over the research by Flegal that overweight people might actually show some better morbidity stats than people who where underweight was evidence enough of that.

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  8. You say “I would still maintain that regularly eating a nutritious breakfast may be the best way to start a day”.


    Do you have any evidence supporting that belief?

    To me, your statement seems just as problematic as recommending breakfast for weight loss (unless you do have data behind it).

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  9. Dr. Sharma,
    thank you for raising this point and questioning the science behind breakfast. Based on my personal experience, breakfast isn’t so crucial for energy, thinking, and appetite control. But, as a health professional I have felt obligated to “strongly encourage breakfast eating”.

    I have never been a breakfast eater, i’m rarely hungry first thing so I have always struggled with this one. I try to be a role model for my kids and eat breakfast, I try to walk the talk as I work with several dietitians (I am a diabetes educator) and we tell our clients breakfast is the most important meal of the day and my husband is a breakfast eater.

    I have found that I do not enjoy food first thing in the morning, and when I force myself to eat breakfast I feel physically uncomfortable – I notice my weight tends to increase as well. I find I have more control over my weight and well being when I eat when I am hungry – which is typically 2-3 hours after waking, not first thing as my colleagues recommend.

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