Effect of breakfast on weight and energy intake: systematic review and meta-analysis of randomised controlled trials

Eating breakfast versus skipping breakfast: a food fight

This note concerns the recent systematic review and meta-analysis by Sievert and colleagues on the effect of breakfast on weight in healthy adults published on January 30, 2019 in BMJ (1). We, a 70 -year old physician-patient with type 2 diabetes engaged in diabetes self-management for over 20 years and her endocrinologist, find the article quite valuable to clinicians, researchers and the public at large. Available data, not always of the highest quality, lead these reviewers to the conclusion that adding breakfast to the daily meals may not be a good strategy for weight reduction in adults as it can have the opposite effect. Specifically they state that breakfast consumption, compared with skipping breakfast, raises the total intake of calories. There is a direct remedy. Make it a moderate breakfast and raise the energy expenditure to cover the added calories. We, therefore, find it necessary to add a word of caution for the vast numbers of diabetes patients always on the lookout for effective strategies for weight reduction: skipping breakfast can backfire and leave us in worse shape overall because, regardless of its impact on weight, breakfast consumption offers real metabolic benefits to people with – or at risk for - metabolic disorders, especially diabetes (2-6).

Mekary and colleagues show that skipping breakfast can increase the risk for diabetes (2). Kahleova and colleagues report that two big meals, breakfast and lunch, are better than six small meals for people with type 2 diabetes (3). Jakubowicz and coworkers find that a high-energy breakfast and low-energy dinner decrease overall daily hyperglycaemia in type 2 diabetes patients (4) and improve weight and different metabolic markers in overweight and obese women (5). The metabolic effects of breakfast are related to the hormone systems operational at the time of the meal and the fuel sources involved, along with the circadian rhythm itself. Counterregulation controls the metabolic activities of the body during the several hours of fasting through the night. Exogenous glucose is not available and the body uses other fuel sources, including free fatty acids, liver glycogen and muscle glycogen. What breakfast does is to switch the hormone system from counterregulatory hormones to the incretin-insulin system, and in 30 minutes or so exogenous glucose becomes the major fuel for the energy needs of the body. By this time free fatty acid levels have fallen and glycogen sparing is on in the liver and muscles. As a result, insulin sensitivity is the highest during the second meal of the day. (This is the so-called second-meal phenomenon (6, 7)). There are also data showing substantial diurnal variation in glucose tolerance in many diabetes patients: insulin resistance is worse in the evening, when people begin to wind down their daily activities (8, 9).

The elderly patient has been under continuous glucose monitoring (Dexcom 5) since July 2017, following two harrowing episodes of seizures brought on by impaired awareness of hypoglycaemia. With the help of CGM, under the watchful eyes of her endocrinologist, she has been testing, among other things, how the diurnal variation in glucose tolerance affects her advanced state of diabetes. She would eat identical meals for breakfast and dinner and keep all other variables, including medications, total carb count (75 gm a day) and physical activity unchanged. (The carb servings are ¾ : 2: 1: ½ : ¾ ). Although the two meals, breakfast and dinner, are identical Breakfast PPG is a lot smaller than the dinner PPG (139 vs 193 mg/dL). Glucose tolerance is high at the second meal and worse at dinner (second meal PPG ~105 mg/dL). The remedy has been to take some carb (¼ carb) from dinner and add it to the breakfast. This improves the glucose profile. Most of the carbs (4 out of 5) in the daily meals are now consumed in the earlier hours of the day and glycaemic variability is lower. This result is in line with what the three previous studies have found (3, 4, 5). This low-carb balanced meal plan is compatible with the circadian clock. A 30 min walk after breakfast and/or after lunch can burn some calories, thereby moderate the glucose surge (10). Consumption of a healthy breakfast in this manner is helpful in weight management also. The Sievert review mentions that observational studies show positive association between breakfast eating and healthy weight in those who are in the habit of making healthy lifestyle choices including not smoking, moderation in alcohol intake and add more fiber in the meals. We would like to reassure people with diabetes and those at risk for metabolic disorders that eating a balanced, healthy, moderate breakfast can offer metabolic benefits and weight loss.

Nature’s conservation laws forbid not just “free” lunches but food at all times that comes without the burden of weight gain. A practical message, therefore, to people with diabetes is this: eat a moderate, nutritious breakfast and go for a half-hour walk starting 30-minutes post-meal.

Funding: This work received no specific funding.
Duality of interest: The authors declare that there is no duality of interest associated with this manuscript.
Author's contribution: Elsamma Chacko: Literature search, study design, data collection, data interpretation; put together the first draft. Christine Signore: Endocrinologist caring for the patient, devised the treatment plan, ordered medications, CGM and lab tests, interpretation and extensive review of the various drafts of the paper.

References

1. Sievert K, Hussain SM, Page MJ et al. Effect of breakfast on weight and energy intake: systematic review and meta-analysis of randomized controlled trials. BMJ 2019; 364 doi:https:/doi.org/10.1136/bmj.142

2. Mekary RA, Giovannucci E, Willett WC, van Dam RM, Hu FB. Eating patterns and type diabetes risk in men: breakfast omission, eating frequency, and snacking. Am J Clin Nutr 2012; 95(5):1182–89

3. Kahleova H, Belinova L, Malinska H et al. Eating two larger meals a day (breakfast and lunch) is more effective than six smaller meals in a reduced-energy regimen for patients with type 2 diabetes: a randomized crossover study. Diabetologia 2013; Springerlink.com. DOI:10.1007/s00125-014-3253-5

4. Jakubowicz D, Wainstein J, Ahrēn B. High-energy breakfast with low-energy dinner decreases overall daily hyperglycaemia in type 2 diabetic patients: a randomized clinical trial. Diabetologia 2015; doi:10.1007/s00125-015-3524-9

5. Jakubowicz D, Barnea M, Wainstein J, Froy O. High caloric intake at breakfast vs dinner differently influences weight loss of overweight and obese women. Obesity 2013; 21(12) https://doi.org/10.1002/oby.20460

6. Jovanovic A, Gerrard J,Taylor R.The second-meal phenomenon in type 2 diabetes. Diabetes Care 2009;32:1199-1201, doi:10.2337/dc08-2196

7. Lee SH, Tura A, Mari A et al. Potentiation of the early-phase insulin response by a prior meal contributes to the second-meal phenomenon in type 2 diabetes. Am J Physiol Endocrinol Metab 2011;301: E984-E990 . DOI:10.1152/ajpendo.00244

8. Reutrakul S, Hood MM, Crowley SJ et al. Chronotype is independently associated with glycemic control in type 2 diabetes. Diabetes Care. 2018; DOI: 10. 2337/dc12-2697

9. Zimmet PZ, Wall JR, Rome R, Stimmler L, Jarrett RJ. Diurnal variation in glucose tolerance: Associated changes in plasma insulin, growth hormone, and non-esterified fatty acids. British Med Journal 1974;4: 485-491

10. Chacko E, Signore C . A physician-patient’s perspective on lowering glycemic variability - part II: the role of exercise. Diabetes Manag 2018; 8(3);057-61

Sievert and Hussain deserve congratulation for their systematic review, if only for highlighting the paucity of good research and the tiny sample size of most of the studies they looked at. While they comment on the high or unclear risk of bias of the studies, they omit clear mention of the potential impact of conflict of interest on the part of the authors. The only large study > 100 participants by Dhurandar et al (2014) states under conflicts of interest "The authors disclose that, although not for the support of this study, the authors or their institutions have received gifts, grants, or consulting fees from multiple organizations that market products commonly consumed at breakfast." In other studies showing positive effects of eating breakfast industry I noticed funding was received variously from Kelloggs, Quaker Oats, and PepsiCo, and the Institute of Life Sciences (recently noted by BMJ to be heavily sponsored by Coca Cola).
As Tim Spector comments NHS guidelines currently recommend breakfast. Breakfast cereal is mentioned as a healthy choice. Yet what is it? Highly processed grain with added vitamins minerals and sugar, so very high in carbohydrate. It is also very effectively marketed. I myself (after personal experimentation) need breakfast to function optimally during the day, but haven't touched the processed stuff for years, as I was always hungry 2-3 hours later.

On behalf of out team, I thank those who raised interesting discussion points regarding this paper. We agree that skipping breakfast is not for everyone. Indeed there are some populations eg diabetic patients on treatment, where distributing calories over the course of the day may be advisable. However, there is no doubt that one of the major medical and public health challenges facing us is the obesity epidemic. We are not winning. It is important that as part of dealing with this challenge we question our beliefs about obesity.

This study came about after I repeatedly saw patients with knee osteoarthritis who were obese, went to seek advice on what to do regarding their weight, and almost invariably were told they need to eat breakfast. A number would then complain that they were really struggling to eat breakfast, they just didn't feel hungry. It never made sense to me that we should be asking people to eat when they are not hungry.

There are some people who love eating breakfast. Others who just don't feel hungry at that time. The key message from this meta-analysis is there there is no evidence that in order to lose weight, we should advise people to change their eating patterns to include breakfast. We found that eating breakfast resulted in an average 260 extra calories per day, and the average weight gain mirrored this, 0.44kg over an average of 7 weeks.

People vary, their needs vary, their preferences vary. However the message that 'breakfast is the most important meal of the day' is very strongly believed in the community and among health porfessionals, to the point that many people are apologetic if they say they miss breakfast, on the assumption that they are not 'being healthy.'

One of the overwhelming responses to our study has been a relief among those who don't eat breakfast, that it is fine to skip it!

It is not really what you call it but when you eat it.

Intermittent fasting is used by many different peoples: some by design and others by need, but it is said to mimic the eating patterns of our ancestors prior to organized agriculture. In doing so we tend to exercise or work on an empty stomach which aids utilization of stored energy. Many call this diet LCHF; Paleo or Primitive but it seemed to sustain many hunter gatherers for thousands of years such that they seemed to have plenty of leisure time and good health.

Many like me only eat within an eight hours window, mine from midday to 8 pm but any that suits one's lifestyle. As a dedicated Low Carb/High Fat eater for some ten years it sustains me and I rarely feel hungry. I often eat 'brunch' (at lunch time) or occasionally, when travelling, will eat a late cooked breakfast and then dinner about 7 pm. My weight hovers around 67kgs all of the time, give or take a half a kilo either way and has done for ten years.

Breakfast is today more a sales opportunity for Big Food, helped by all of the Institutions of the State, who have colluded to the detriment of the health of our peoples, especially our children, to promote foodstuffs that were never meant to be eaten by humans. And not just breakfast cereals but manufactured fats/oils; milk from nuts (sic); so called 'smoothies' with more fruit than you would likely eat in natural form in a week, providing a fructose load that (with other sugar laden 'healthy' drinks), is contributing to the growth of NAFLD.