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Breakfast Boosts Metabolism – Fact or Fiction?

Have you ever wondered if breakfast really boosts your metabolism—as you so often hear?


As a health educator I can give you a lot of good reasons to eat breakfast—the notion that it boosts your metabolism, however, isn't one of them!

Digesting food does “cost” an average of 10% of a meal's calories to digest and assimilate it (see TEF, below). However, is that really a “boost” in metabolism? No, it is not. When you read these claims that "breakfast boosts your metabolism" it's implied that eating breakfast has an affect on your underlying metabolic rate. That is simply not the case. The only metabolic affect of eating breakfast is the commensurate TEF, just as for any meal.

So then, is there any advantage to when the food is eaten? No, again. Some studies may show small differences in TEF when calories are distributed in different ways, but arguably none of the differences are of practical significance. TEF remains an average of the calories consumed without any affect regarding when they’re consumed.

Your Metabolism—Specifically Your Total Energy Expenditure (TEE)—Consists of Three Components:

  • RMR (Resting Metabolic Rate) - accounts for 65- to 75% of daily total energy expenditure for the average person. RMR consists of the cost of involuntary activities necessary to sustain life (liver and kidney functioning, heart pumping, etc., etc.)
  • TEF (Thermal Effect of Food) - is the energy cost associated with digesting and assimilating what we eat. Both balanced diets and high-carboyhdrate diets are assoiciated with an average TEF of 10%, while for a typical high protein diet the TEF will amount to 12- to 13% of calories ingested.
  • Activity of Daily Living - The energy cost of all body movement, including exercise, and even the muscle tone necessary for sitting.

Metabolism aside, eating breakfast has long been associated with lower body weights, so what exactly is going on? People who eat breakfast, tend not to be night-eaters/night snackers. People who snack after dinner eat more calories on average than those who don’t, and have a poorer quality diet overall. In most cases, they are also not hungry in the morning.

The Bottom Line: The notion that eating breakfast boosts your metabolism is FICTION. People with healthier overall lifestyles simply tend to eat breakfast, have better quality diets, get more exercise, and therefore tend to have lower body weights.

Actionable advise: Encouraging non-breakfast eaters to eat breakfast overlooks the primary problem that needs to be solved: night-eating. Until the night-eating is addressed, focusing on breakfast will be a fruitless endeavor. If you want to get a handle on night-eating read my blogs on stimulus control.


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Related articles:
Information you can trust? Or, your daily dose of misinformation?
Protein Mythology... Get the Facts!

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