Is Breakfast ‘The Most Important Meal of The Day’ for Dieters?

Yesterday's breakfast

I once had a very religious friend confess that, in spite of ‘living every moment for Jesus’ it's breakfast that gets him out of bed in the morning. I can relate.  Chocolate pancakes are worth getting up for, but is breakfast really ‘the most important meal of the day’ if you're in lardbusting mode?

As the world gets progressively fatter, the impact of breakfast eating on weight and weightloss (‘adiposity’) has attracted the attention of the scientific community, diet book authors and cereal company marketing teams. It's hard to keep a straight head about it sometimes:

"The Warrior Diet and Eat Stop Eat suggest breakfast is optional, or even detrimental, but the Zone Diet and the Weetbix ad tells me I'll be fat and stupid if I don't eat it... what to dooooo??! OMG, I don't want to be fat!"



This post is a quick overview of what some studies have revealed when investigating the question: ‘what is the relationship between breakfast and adiposity?’

Overall, the research concurs that breakfast scoffing is beneficial to body composition and reduces the risk of obesity-linked conditions.  Indeed, it is frequently noted^4,5 that the ‘obesity epidemic’ and rise in related diseases (heart disease, diabetes) has occurred in tandem with a decrease in breakfast consumption. Breakfast skipping correlates with overeating, weight gain and a higher BMI in both children and adults^5,8 and with increased general consumption of low-nutrition foods such as ‘meat pies.. sausage rolls, chocolate sweets … candies and soft drinks’⁸. Up to 75% of overweight adolescents (whom are more likely to become overweight adults) skip breakfast⁵.

Breakfast eaters are more likely to eat recommended quantites of fruit and vegetables, less likely to snack and if they do snack, it is less likely to be junkfood⁸.  Breakfast elicits an appetite suppressing and satiating effect which means that breakfast eaters should, in theory, eat less during the rest of the day.  This satiating effect is greater when the breakfast is higher in calories or protein⁵.  Breakfast content is an interesting area, actually. For example, this study (thanks Julianne)showed that a higher calorie breakfast that included dessert resulted in continued weight loss over the long term compared to weight regain in study participants that didn’t get the bumped up brekky.

Most (but not all) studies I reviewed concluded that breakfast eaters are less likely to be overweight, even though they do not appear to eat fewer calories¹.  Based on that, it would seem that the link between breakfast and adiposity is straight-forward. Breakfast eaters wear smaller jeans. However, other studies mess with this apparently neat correlation.

The most consistently confusing finding is that the satiety and appetite suppressing effect of breakfast may or may not result in eating less over a day than breakfast skipping⁵. That is some breakfast eaters still eat more than breakfast skippers even though they report feeling subjectively less hungry.  This leads to the big question: why are breakfast eaters leaner? 

None of the studies reviewed addressed this perplexing issue directly, although some² noted it as an underexplored ‘biological phenomena’ (the mythical metabolic effect).  Others⁴ came right out and claimed that study participants lie about how much they eat. It is well known that the dietary data collection methods of 24 hour dietary recall and self-report are prone to error. It is also well accepted that the most overweight are also most likely to under-report their intake. This leads to a false ‘breakfast skippers are fatter even though they eat less’ result which disappears if the recall results are adjusted for the expected degree of under-reportage.

Other research has presented findings which could best be described as ‘spanner in the works’ for the breakfast / adiposity correlation. Most research involves taking breakfast skippers and making them eat breakfast or vice-versa, but few have done both. In one particularly interesting 1992 study^7, a group of breakfast eaters and a group of non breakfast eaters, both overweight, were randomly assigned to either the breakfast-eating or breakfast-skipping condition as part of a calorie controlled diet. Surprisingly, while all participants lost weight, those that had changed their habitual breakfast habit (i.e. usually eat it, but stopped for the study, or usually don’t eat it, but did during the research) lost significantly more weight (1.8-2.8 kg) over 12 weeks than those that maintained their regular schedule. I found this fascinating. Did the act of paying attention to a new routine result in eating less, or is it some wacky metabolic adaptation to change that caused the extra fat-busting to happen? Unfortunately this finding does not seem to have received any follow-up attention.

This same study found that non-breakfasters reported easier compliance in social situations, as they could eat more while maintaining their calorie limit, but that breakfast eaters showed less impulsive snacking and made healthier choices. Importantly, these researchers discovered that the lower nutritional status of non-breakfast eaters was almost entirely due to unhealthy snacks eaten later in the day. They proposed that this effect could be negated by encouraging healthy snacking habits in non-breakfast eaters. Another study which presented head-scratching results was a longitudinal study³, which unexpectedly found that the breakfast skipping child => overweight adolescent correlation only held up if the breakfast skipper was normal weight when they began skipping breakfast. If they were overweight when they started skipping breakfast then generally they lost weight over time.

Apart from the design and results interpretation issues already mentioned, there is concern with the relationship of non-breakfast consumption to sociological factors. For example, a New Zealand based study⁸ showed a strong link between breakfast skipping, ethnicity and deprivation. As ethnicity and deprivation independently correlate with obesity⁶, this raises questions of causation. Overall, there is a problem with establishing directionality of the breakfast / adiposity relationship, with researchers being unable to decide whether the apparent success of breakfast as a slimming tool is due to the influence of energy intake, undefined metabolic factors or ‘other lifestyle factors associated with breakfast consumption’². For example, as well as eating more fibre and nutrients, and less fat and alcohol, breakfast eaters tend to be non-smokers and more likely to exercise⁴. 

Altogether, the studies I read (fine bedtime reading, very relaxing) suggest that breakfast does influence body composition, but that we are not sure how or why. However, research continues! An upcoming trial hopes to clear some of the confusion. The Bath Breakfast Project (BBS)⁴ is a current undertaking by the University of Nottingham. It is a breakfast vs. no breakfast study that controls for an astonishing array of variables, including exact food intake measurement and the neglected area of physical activity – to this point few studies have considered the impact that no breakfast may have on daily energy output⁴. The BBS measures some very geeky things, such as metabolic and behavioural changes in energy regulation, gene expression in the adipose tissue, continuously monitored blood glucose and dietary-induced thermogenesis (effect of breakfast on the metabolic rate). With this, and other research which will undoubtedly follow, we may eventually have a more exact idea of exactly how important that ‘most important’ meal is for those on a lard-busting mission.

For now the best plan seems to be: know thyself.  Experiment and find what works for you. When it stops working, change something. If you are eating cereal every morning and getting nowhere, try an omelette, or try skipping breakfast one day and see how that works out. If you habitually skip breakfast and your fatloss is at a standstill, try adding it back. I've had good results being a breakfast eater and a breakfast skipper. The trick is to not think that skipping breakfast gives you the right to eat a whole cake later. Mmmkay?

What about you? Are you a breakfast eater? Breakfast skipper? Intermittent faster?

Tell me what works for you.

References:

1. Affenito, S. (2007) Breakfast: a missed opportunity. Journal of the American Dietetic Association, 107(4). 565-569.

2. Astbury, N., Taylor, M., Macdonald, I. (2011). Breakfast consumption affects appetite, energy intake and the metabolic and endocrine responses to foods consumed later in the day in male habitual breakfast eaters. The Journal of Nutrition, May 11, 2011, 1381-1389

3. Berkey, C., Rockett, H., Gillman, M., Field, A. & Colditz, G. (2003). Longitudinal study of skipping breakfast and weight change in adolescents. International Journal of Obesity and Related Matabolic Disorders, 27, 1258-1266.

4. Betts, J., Thompson, D., Richardson, J., Chowdhury, E., Jeans, M., Holman, G. & Tsintzas, K. (2011). Bath breakfast project (BBP) – Examining the role of extended daily fasting in human energy balance and associated health outcomes: study protocol for a randomized controlled trial. Trials, 12(172). 1-12.

5. Leidy, H. & Racki, E. (2011) The addition of a protein-rich breakfast and its effects on acute appetite control and food intake in ‘breakfast-skipping’ adolescents. International Journal of Obesity, 34, 1125-1133.

6. Ministry of Social Development (2007). Obesity. Retrieved 14 March 2012 from: http://socialreport.msd.govt.nz/health/obesity.html

7. Schlundt, D., Hill, J., Sbrocco, T., Pope-Cordle, J. & Sharp, T. (1992). The role of breakfast in the treatment of obesity: a randomized clinical trial. American Journal of Clinical Nutrition, 55, 645-651.

8. Utter, J., Scragg, R., Mhurchu, C. & Schaaf, D. (2007). At home breakfast consumption among New Zealand children: associations with body mass index and related nutrition behaviours. Journal of the American Dietetic Association, April 2007, 570-576.