CLAIM #1: Breakfast Boosts Your Metabolism... (#1 of 9 "Boost Your Metabolism" Claims that are Actually False)
Saturday, January 13, 2018 at 10:52AM 
Metabolism-boosting hype generally has a grain of truth behind it that has been way overblown. In other cases, long disproved theories continue to be touted because they are super effective as click-bait (or selling books). You rarely see any actual numbers -- how many calories per day will this raise my resting metabolic rate? -- attached to claims. That’s because for the most part the actual increase in resting metabolic rate (or other components of your daily total energy expenditure), is too small to be of any practical significance.
Metabolism mythology has a life of its own though as it gets regurgitated and reposted throughout the internet and fad-diet books (and unfortunately even by many otherwise reputable sources).
Each of the following false and misleading "Boost Your Metabolism" topics will be discussed in a separate blog over the next couple weeks (not necessarily in this order): Breakfast, Build Muscle, Meal Frequency, Water, Cheat Meals, EPOC, Hot Peppers, MCTs, and Eating after 7pm.
Myth #1: Breakfast boosts your metabolism.
Claims and advice that eating breakfast in some way promotes weight management continue to be doled out despite a lack of evidential support.[i] This problem is so pervasive that it was the topic of a 2013 scientific paper (by highly respected researchers from University of Alabama at Birmingham's NIH-funded Nutrition Obesity Research Center) basically admonishing the scientific community for biased research, and calling on it to do better.[ii]
Some of the false claims regarding breakfast:
CLAIM: Your metabolism will be higher all day if you start with breakfast
The FACTs: the metabolic response to eating breakfast is not different than that to eating food at any time later in the day.[iii] Digesting and assimilating what you eat is called the thermic effect of food (TEF), and by definition TEF is measured as the energy expenditure above resting metabolic rate in response to eating.[iv] [v]
CLAIM: Skipping breakfast leads to overeating later in the day.
The FACTs: When breakfast is omitted from the daily meal pattern (skipped) calorie intake at the end of the day is generally lower. In other words, the calories missed at breakfast are not completely offset by eating more at lunch or dinner. So at the end of the day an energy deficit remains.
CLAIM: Skipping breakfast makes you hungry.
The FACTs: The effect of breakfast on satiety is transient and not more advantageous than the next meal of the day provides independent of breakfast.[iv] Note however, that habitual breakfast-eaters and habitual breakfast-skippers respond differently. That's because your body adjusts to the pattern you usually follow so that it "expects," that pattern. So if you usually eat breakfast, and you try skipping it you’re going to be extra hungry for lunch. On the other hand, breakfast skippers aren’t hungry for breakfast to begin with, and eating breakfast is like a curve ball disrupting their system in a different way (which may be why some people claim that eating breakfast makes them more hungry).
Evidence (from well done randomized controlled trials) does seem to show:
- That breakfast eaters may have higher morning physical activity levels (via less sitting/more moving around) compared to breakfast skippers.[vi]
- People who regularly eat breakfast tend not to be night eaters, so they are hungry when they get up.
- Habitual breakfast eaters also tend to be non-smokers, consume less fat and alcohol but more fiber and micronutrients, and are more physically active.[vii]
Clearly, trying to attribute differences in BMI between breakfast eaters, or skippers, is not a straightforward endeavor.
It is important to note that for diabetics eating breakfast results in lower insulin and blood glucose levels for the rest of the day. So, it is very important that diabetics eat breakfast.
For everybody else, you can stick with what works for you because eating breakfast does NOT increase your (resting) metabolism, improve appetite regulation, or reduce overall energy intake. TEF from breakfast is no different, and provides no advantage over, the TEF from any other meal.
The problem with boost-your-metabolism myths is that they distract you from focusing on what actually works, and propagate the notion that there are simple tricks or magical methods that promote weight loss. The best advice remains to be: eat a healthy diet, but not too much, and make activity a part of your day.
All the best!
-Dorene
References:
[i] Meal skipping and variables related to energy balance in adults: a brief review, with emphasis on the breakfast meal. McCrory, MA. Physiol Behav 2014;134:51-54.
[ii] Belief beyond the evidence: using the proposed effect of breakfast on obesity to show 2 practices that distort scientific evidence. Brown, et al. Am J Clin Nutr 2013;98:1298-1308.
[iii] The Energy Content and Composition of Meals Consumed after an Overnight Fast and Their Effects on Diet Induced Thermogenesis: A Systematic Review, Meta-Analyses and Meta-Regressions. Quatela, et al. Nutrients 2016;8(11)670.
[iv] The effect of breakfast on appetite regulation, energy balance and exercise performance. Clayton and Lewis. Proc Nutr Soc 2016;75(3):319-327.
[v] Effect of breakfast skipping on diurnal variation of energy metabolism and blood glucose. Kobayashi, et al. Obes Res Clin Prac 2014;8(3):e201-98.
[vii] The effectiveness of breakfast recommendations on weight loss: a randomized controlled trial. Dhurandhar et al. Am J Clin Nutr 2014;100:507–13.
[viii] The causal role of breakfast in energy balance and health: a randomized controlled trial in lean adults. Betts, et al. Am J Clin Nutr 2014;100:539-547.
