Re: Effect of breakfast on weight and energy intake: no generalization allowed
the systematic review by Sievert and colleagues published in the BMJ 30 Jan. 2019 (1) calls the attention of the scientific community and general practitioners on the important question of the nutritional value of breakfast and, in particular, on its relationship to overweight and obesity. Based on the meta-analysis of the available randomized controlled trials of the effects of breakfast on daily energy intake and body weight, the authors reported that eating vs skipping breakfast on a regular basis was associated with a tendency to greater energy intake and larger weight gain in contrast to what expected based on previous evidence coming mainly from prospective observations (2). We appreciate that the authors acknowledged the important limitations of their study, yet we are worried that a superficial reading or a mistaken interpretation of their paper may generate in public health operators, let alone in lay people, the idea that skipping breakfast is an acceptable if not a beneficial practice for everyone. Thus, it may be worth to underscore the reasons why the results of this meta-analysis should not lead to draw any such type of conclusion:
- The included studies were not numerous, heterogeneous and some of them definitely undersized;
- The large majority of the samples was made of obese women;
- All the studies were judged to be low quality with particular regard to lack of blindness for intervention or control group allocation as well as for outcome assessment;
- There was high heterogeneity across trial results with just a few studies shaping the pooled effect;
- The between-group difference in weight change did not actually achieve statistical significance.
Curiously enough, in one of the studies that reported separate results for habitual breakfast eating participants and habitual breakfast skippers (3), the subgroup used to have breakfast regularly gained weight while on breakfast whereas the subgroup habitually not having breakfast paradoxically lost weight while on breakfast.
We believe that the authors’ effort may at most point out the need for further careful evaluation of the recommendation to introduce breakfast in hypocaloric regimens for obese people who are not used to have it and might thus increase their overall energy intake. On the other hand, it would be quite inappropriate and totally misleading to generalize these weak study findings to the general population, as unfortunately the article title may suggest. The bulk of the available evidence in fact supports the beneficial role of the regular consumption of a healthy breakfast with regard to overall adequacy of the diet, to the cardiometabolic risk profile, to the risk of diabetes and even to cognitive performance, especially in youth (4).
1. Effect of breakfast on weight and energy intake: systematic review and meta-analysis of randomised controlled trials. Sievert K, Monira Hussain S, Page MJ, Wang Y, Hughes HJ, Malek M, Cicuttini FM. BMJ 2019;364:l42. http://dx.doi.org/10.1136/bmj.l42
2. O'Neil CE, Byrd-Bredbenner C, Hayes D, Jana L, Klinger SE and Stephenson-Martin S. The role of breakfast in health: definition and criteria for a quality breakfast. J Acad Nutr Diet 2014; 114: S8-S26
3. Schlundt DG, Hill JO, Sbrocco T, Pope-Cordle J, Sharp T. The role of breakfast in the treatment of obesity: a randomized clinical trial. Am J Clin Nutr 1992;55:645-51. doi:10.1093/ajcn/55.3.645
4. Chaplin K and Smith AP. Breakfast and snacks: associations with cognitive failures, minor injuries, accidents and stress. Nutrients 2011; 3: 515-528.
Pasquale Strazzullo, Department of Clinical Medicine and Surgery, Federico II University of Naples, Naples, Italy (President, Italian Society of Human Nutrition), firstname.lastname@example.org;
Andrea Ghiselli, Research Centre on Agricultural Economy and Nutrition, Rome, Italy (President, Italian Society of Food Science);
Giulia Cairella, Department of Prevention, Sector Nutrition, ASL RmB, Rome, Italy;
Valeria Del Balzo, Department of Experimental Medicine, Research Unit of Food Science and Human Nutrition, "Sapienza" University of Rome, Rome, Italy.
Competing interests: No competing interests