By Caitlin Dow, PhD
Breakfast is often considered the “most important meal of the day,” and if you are looking to lose weight, you mustn’t skip breakfast… or so the story goes. This idea is widely believed in popular culture as well as by many nutrition scientists and government bodies and is repeated so often that many in the field consider it health dogma. Indeed, the Dietary Guidelines for Americans even recommend breakfast consumption as an important tool for weight loss. But what does the science say?
Observational studies indicate that breakfast consumption is linked to lower weight. Data from the National Weight Control Registry demonstrated that 78% of the nearly 3,000 subjects included in the analysis (adults who had lost at least 13 kg and kept the weight off for a year or more) reported eating breakfast everyday and only 4% reported never eating breakfast [1]. Further, a recent meta-analysis of observational studies that have evaluated the relation between weight and breakfast consumption found that skipping breakfast was associated with a 55% increased odds of having overweight or obesity [2]. These findings are likely the reason many tout breakfast consumption as an important weight loss modality, despite these studies not actually testing that outcome.
Observational studies can only describe associations, but are not appropriate to determine causation. Thus, randomized controlled trials (RCTs) have sought to test whether breakfast consumption directly impacts weight. In one of the first RCTs to evaluate the role of breakfast in weight loss, Schlundt et al. [3]studied women with obesity who were self-reported breakfast eaters or skippers.Within each group, women were randomized to eat or skip breakfast in addition to following a 1200 kcal/day diet for 12 weeks. All groups lost at least 6 kg, but interestingly, those who were randomized to switch their breakfast condition (e.g. ate breakfast at baseline, then started skipping) lost more weight than those who maintained their breakfast habit. These results suggest that changing an eating behavior in addition to following a reduced calorie diet may accelerate weight loss. However, the results from a study by Dhurandhar et al. did not corroborate those findings. Adults with overweight and obesity were randomized to one of three conditions in which all groups received a USDA pamphlet on healthy eating practices: the control group received no other information, one group received additional instructions to consume breakfast, and the third group was instructed to not eat breakfast [4]. After 16 weeks, there was no observed effect of treatment assignment on weight loss.Contrary to the results from the Schlundt study, baseline breakfast eating habit was not related to weight change, though this study didn’t evaluate breakfast consumption in conjunction with a reduced calorie diet.Finally, in a recently published 4-week study, adults with overweight and obesity were randomized to three different breakfast conditions: water (control), frosted flakes, or oatmeal [5].Interestingly, skipping breakfast resulted in an average weight loss of 1.2 kg, while those randomized to either breakfast condition demonstrated no significant weight change.However, total cholesterol also increased in the control group, suggesting that skipping breakfast may result in slight weight loss, but have detrimental effects on cardiometabolic health.
Thus, the results from the few RCTs completed in adults with overweight and obesity, to date, do not support the notion that breakfast consumption should be part of a weight loss regimen. Importantly, though, the results are also not compelling to suggest that eating breakfast hinders weight loss. This field is still young and many questions remain unanswered. I look forward to more RCTs evaluating breakfast consumption (and potentially, breakfast quality) on various facets of weight and metabolic health.
References
1.Wyatt, H.R., et al., Long-term weight loss and breakfast in subjects in the National Weight Control Registry. Obes Res, 2002. 10(2): p. 78-82.
2.Brown, A.W., M.M. Bohan Brown, and D.B. Allison, Belief beyond the evidence: using the proposed effect of breakfast on obesity to show 2 practices that distort scientific evidence. Am J Clin Nutr, 2013. 98(5): p. 1298-308.
3.Schlundt, D.G., et al., The role of breakfast in the treatment of obesity: a randomized clinical trial. Am J Clin Nutr, 1992. 55(3): p. 645-51.
4.Dhurandhar, E.J., et al., The effectiveness of breakfast recommendations on weight loss: a randomized controlled trial. Am J Clin Nutr, 2014. 100(2): p. 507-13.
5.Geliebter, A., et al., Skipping breakfast leads to weight loss but also elevated cholesterol compared with consuming daily breakfasts of oat porridge or frosted cornflakes in overweight individuals: a randomised controlled trial. J Nutr Sci, 2014. 3: p. e56.
