January 30, 2019

expert reaction to study on eating breakfast and weight loss

Research published in the BMJ suggests that eating breakfast may not help with weight loss and could have the opposite effect.

Prof. Kevin Murphy, member of the Society for Endocrinology and Professor of Endocrinology & Metabolism, Imperial College London, said:

“The evidence that eating breakfast helps you lose weight largely comes from studies observing people ‘in the wild’, and the suspicion is that those people who usually eat breakfast might be different in other ways (for example, they may eat more healthily in general). This study suggests that in trials where you are potentially asking people to change whether they eat breakfast, in fact breakfast is likely to drive people to eat more calories during the day.

“It is a high quality paper, but there does need to be some caution because, as the authors note, the evidence that they assess is inconsistent across different studies. People trying to lose weight shouldn’t feel that they have to eat breakfast to be successful – the likelihood is that while it may help some people as part of an overall healthy lifestyle, it won’t help everyone, and may in fact make weight loss more difficult for many.

“I think it helps to overturn the assumption that periods without food will just make us compensate by eating more later- under some conditions, restricting our food intake may not be compensated for in this way.”

Dr. Gerda Pot, Visiting Lecturer in Nutritional Sciences, King’s College London, said:

“’Eat breakfast like a king, lunch like a prince and dine like pauper?’ This saying cannot be discarded based on the findings of this systematic review. Though this systematic review summarized some recent data of randomised controlled trials (RCTs) on the effects of breakfast consumption on weight and energy intake, the included studies of this review were too heterogeneous and too low quality, to be able to draw firm conclusions. The mean study duration was 7 weeks with a range of 24h to 16 weeks so these RCTs do not reflect habitual consumption. In addition, participants in these RCTs are US/UK adults with obesity so the findings cannot be extrapolated to everyone. For example, nowadays many people with obesity also suffer from other co-morbidities like type 2 diabetes for whom consuming or skipping breakfast may have different effects. 

“I think that the impact of breakfast on weight status is more related to regularity (a part of chrono-nutrition, studying the impact of the timing of eating), so whether you have breakfast every day or whether there is a large day-to-day variation in breakfast consumption (meaning having breakfast one day and skipping it the next). Your body’s metabolism is most optimal when there is little day to day variation. Studying the impact of when we eat next to what we eat is called chrono-nutrition and is a recent addition to nutritional research. This element of chrono-nutrition should be considered when interpreting the results of studies on breakfast consumption.”

Prof. Tom Sanders, Emeritus Professor of Nutrition and Dietetics, King’s College London, said:

“The findings of this study which suggest that people who skip breakfast consume 260 few calories a day are not credible. If this were true after a year they would be more 10 kg lighter. The difference in weight reported 0.44 kg is not meaningful and could just reflect differences in large bowel content as people who eat breakfast usually have higher fibre intakes which increase the bulk of food residues in the large bowel. So the conclusion that there is no adjustment in appetite for skipping breakfast is clearly wrong.

“The major weakness is the unreliability of the methods used to measure food energy intake – particularly recall methods. A further weakness is a failure to recognise that breakfast varies in size. A full English/American breakfast typically supplies over 1000 kcal whereas the more widely consumed cereal breakfast is no more than 400 kcal. Buffet breakfast also often result in high energy intakes where some people cannot resist the temptation to pile their plates high. In the UK, children who are from low income groups who do not consume breakfast cereals were more likely to have poorer diets and to be overweight (Holmes et. al.2012). It would be unfortunate if this report was used to discourage people from eating breakfast.”

Prof. James Betts, Professor of Metabolic Physiology, University of Bath, said:

“Meta-analyses can be a useful way to combine the results from many individual studies that have all provided answers to a similar question. My reservation with a meta-analysis on this particular topic is that the few original studies completed to date do not really ask the same question at all. There are a number of reasons for this but the primary issue is that the very concepts of breakfast consumption versus skipping are not well-defined, so the results reported in response to breakfast in one trial might not be attributed to that treatment in another (or could conceivably even be reported for the fasting trial!). It is therefore entirely unsurprising that this meta-analysis reports ‘inconsistency’ when combining the results of such conceptually different trials. Nonetheless, the overall findings that breakfast does not have clear effect on weight loss but may result in higher overall energy intake are consistent with everything we knew already based on numerous earlier reviews of the available evidence.

“One final point is that the authors call for more rigorous and higher quality trials on the basis that all 13 papers included in their review were classified as ‘high risk of bias’ on at least one domain of assessment. However, this was always going to be the case because full blinding of the experiment was one of the criteria and every one of the studies was therefore deemed high risk on that basis. Clearly, not only do research volunteers tend to notice when they are having or skipping breakfast for many weeks but, moreover, they should be aware of that fact in order for the findings of the study to be give valid information for public guidelines (i.e. many of the outcomes in studies in this area rely on our behavioural responses when we are aware whether or not we had breakfast, as is the case in real life).”

‘Effect of breakfast on weight and energy intake: systematic review and meta-analysis of randomised controlled trials’ by name of Sievert et al. was published in The BMJ at 23:30 UK time on Wednesday 30^th January.

All our previous output on this subject can be seen at this weblink: http://www.sciencemediacentre.org/tag/obesity/

Declared interests

Dr. Gerda Pot: “None.”

Prof Tom Sanders: “Honorary Nutritional Director of HEART UK.  Scientific Governor of the British Nutrition Foundation.  He is now emeritus but when he was doing research at King’s College London, the following applied: Tom does not hold any grants or have any consultancies with companies involved in the production or marketing of sugar-sweetened drinks.  In reference to previous funding to Tom’s institution: £4.5 million was donated to King’s College London by Tate & Lyle in 2006; this funding finished in 2011.  This money was given to the College and was in recognition of the discovery of the artificial sweetener sucralose by Prof Hough at the Queen Elizabeth College (QEC), which merged with King’s College London.  The Tate & Lyle grant paid for the Clinical Research Centre at St Thomas’ that is run by the Guy’s & St Thomas’ Trust, it was not used to fund research on sugar.  Tate & Lyle sold their sugar interests to American Sugar so the brand Tate & Lyle still exists but it is no longer linked to the company Tate & Lyle PLC, which gave the money to King’s College London in 2006.  Tom also used to work for Ajinomoto on aspartame about 8 years ago.  Tom was a member of the FAO/WHO Joint Expert Committee that recommended that trans fatty acids be removed from the human food chain.  Tom has previously acted as a member of the Global Dairy Platform Scientific Advisory Panel and Tom is a member of the Programme Advisory Committee of the Malaysian Palm Oil Board.  In the past Tom has acted as a consultant to Archer Daniel Midland Company and received honoraria for meetings sponsored by Unilever PLC.  Tom’s research on fats was funded by Public Health England/Food Standards Agency.”

Prof. James Betts: “My own research on breakfast was funded by the BBSRC, I have also had research grants and completed consultancies with GlaxoSmithKline, LucozaedRibenaSuntory, Kellogg’s, Nestle and PepsiCo, and am an expert member with International Life Sciences Institute (Europe). I also rarely have breakfast myself!”

None others received.