I recently came across the following weight loss advice from “Biggest Loser” trainer Bob Harper in Shape Magazine (February 2011, page 171):
“Eating first thing revs your calorie burn…If you don’t eat within two hours of waking, your metabolism can slow down to conserve energy.”
Arrggh! What will it take to put a stake through the heart of this myth-that-will-not-die? Bob Harper and Shape are not the first to perpetuate this urban legend and I’m sure they won’t be the last. But, c’mon! A guy of this clout and a magazine of this caliber should do better than repeat well-worn nonsense. They should be a beacon of accuracy in the swirling fog nutrition misinformation. And so, I’d like to issue…
A Friendly Challenge to Mr. Harper and the Editors of Shape:
If you can produce one shred of evidence or data to support this statement, I will personally treat you all to breakfast–a protein-rich and high fiber breakfast, of course.
I’m not talking about anecdotal observations or the say-so of smart, famous, or good-looking people. I’m looking for any actual verifiable data that supports this mother-of-all-nutrition-myths.
To the best of my knowledge, there isn’t any. Although it’s true that your metabolism will slow down to conserve energy after a prolonged fast, this does not happen if you go two hours–or even twelve hours–without eating. In fact, it takes at least two days of fasting or severe caloric restriction to trigger any metabolic adjustment.
Related Content: Metabolism Myths
And although it’s constantly repeated by various weight loss gurus, this idea that eating breakfast “revs your metabolism” is, as far as I can determine, a completely unsubstantiated urban legend. It’s not just that it’s never been definitively proven. It’s actually been proven false in at least one study.
It’s True: Breakfast Can Support Weight Loss.
There are plenty of legitimate arguments for eating breakfast, and Shape goes on to list a couple of them.
- Dieters who eat breakfast are more successful, both at losing weight and keeping it off, than those who don’t.
- Eating breakfast may make it easier to resist temptations later in the day. (One caveat, however: For people who are not carefully monitoring their calorie intake, eating breakfast tends to increase their total calorie intake over the course of the day.)
Related Content: Can Eating Breakfast Help You Lose Weight?
I’m Not Against Breakfast; I’m Against Misinformation
It’s not that Shape is giving out bad advice. But what do we gain by supporting good advice with made-up facts? Unless Harper has some scientific back-up for the idea that breakfast speeds metabolism or that skipping breakfast shuts it down, I wish he would use his considerable influence to spread good science instead of reinforcing urban legends.
So, can I buy anyone breakfast?
I’m sure multi-millionaire Bob Harper wants your free breakfast.
Even if he did, I don’t think there’s much danger I’d have to pay up on this wager. So the real question isn’t whether he wants my breakfast. It’s whether he’s interested in setting the record straight!
I look at him more as a salesman than a source of good information. The Biggest Loser has so many obvious product placement (Subway, Britta, Larabar, Kelloggs, etc) that his endorsement has become meaningless to me. Can’t blame him for taking the big bucks, though.
Part of the difficulty may be in definitions. It’s similar to the popular way of referring to the energy content in food as how many calories are “in” it. Calories are not “in” food in the same sense that vitamins are, for example. But, we tend to think that way.
Is “slower metabolism” such a shorthand for something legitimate?
Interesting point about calories. And it is true that “metabolism” means different things to cellular biologists than it does to the lay public. But I don’t think that this boils down to a semantic misunderstanding.
The clear implication of this statement–and all it’s variations–is that eating breakfast will cause your body to burn more calories throughout the day (via an increase in BMR) than you would if you had skipped breakfast. And that, as far as I can tell, is patently untrue.
Not just because I’m hoping to cash in on that breakfast, although partly for that reason, I’m going to venture another stab (an admittedly charitable stab) at this.
“Eating first thing revs your calorie burn…If you don’t eat within two hours of waking, your metabolism can slow down to conserve energy.”
Is it possible that the author did not mean BMR? Your basal metabolic rate is the lowest point at which your body is, to use the technical term, doing its thing. When you are sleeping, or even sitting on the couch watching “Biggest Loser,” your body is probably doing its thing at or very near BMR. When you wake up for a midnight snack, your body does its thing at a somewhat higher rate, both as you walk to the refrigerator and as it digests the empty calories in your Twinkie. Same as if you much on chips while watching TV – your body gets a metabolic boost. In other words, it is now doing more, using more energy, than it did without all that good food.
Would it be correct if we were to reword the objectionable quote to read thus:
“Eating first thing uses more energy …If you don’t eat within two hours of waking, your metabolism is functioning close to your BMR. Eating actually means that your body has to use energy to digest the food.”
Gene, I think I follow your logic but I think what you are describing is the Thermic Effect of Food (TEF), or the energy that we have to spend in order to digest our food. I talk a bit about the TEF in this episode of my podcast. http://nutritiondiva.quickanddirtytips.com/metabolism-myths.aspx
You are not the only one to be thinking along these lines, that because our bodies spend energy to digest food, eating will somehow increase the number of calories we burn. It does, but not nearly as much as eating increases the number of calories we take in. So in terms of energy balance (which is what matters for weight loss), you’re not getting ahead.
In response to a similar query on my Facebook page, I tried to illustrate the arithmetic with following set of scenarios, using round numbers for the sake of simplicity.
Let’s say my baseline metabolic rate is 100 calories an hour.
Scenario 1: I wake up at 8am and don’t eat until 10am, so I simply continue to burn calories at my BMR of 100/hr; no “revving of the metabolism.” At 10am, I eat a 300 calorie meal, which “revs my metabolism” via the TEF. The TOTAL impact of TEF is about 10% of the calories of the meal, so in this case, my “revved metabolism” burns an extra 30 calories. Let’s tally it all up: At 12pm, I’ve burned 400 calories (100/hr BMR), plus 30 (TEF of meal), and I’ve taken in 300. My NET calorie balance at that point is -130. (300 calories in minus 430 burned.)
Scenario 2: I wake up at 8am and immediately eat a 300 calorie breakfast. The TEF causes a rise in my metabolic rate during digestion, accounting for an additional 30 calories burned above and beyond my BMR. At 12pm, I’ve burned 400 calories (100/hr BMR), plus 30 (TEF of meal), and I’ve taken in 300. My NET calorie balance at that point is -130. (300 calories in minus 430 burned.)
So what does this early morning “revving of the metabolism” accomplish in terms of helping dieters burn more calories? Absolutely nothing.
OK, I think I get it. The take away is: No free breakfast for Gene.
Is that right?
I completely agree, Monica. I am always humored and appalled at the abuse of misinformation out there concerning nutrition. I am studying cellular and molecular nutrition right now and it does take substantial ‘starvation’ to go down the road of using different metabolic pathways. The human body is pretty smart and efficient (but this isn’t an excuse to eat stupidly!). Anyway, thanks again for standing up and informing the public as always.
I’d like to know what, if any, response you receive. Surely Mr. Harper and the Editors will hear about your post. I’m sure many of your followers are interested both in their response and in what evidence they provide. You’ve always been careful about having research to back up your info, so there will have to be some very significant, peer-reviewed data to refute your assertion. Not likely forthcoming in my opinion. Thanks.
I’d be surprised to hear from them…but you never know!
I’ll bet Mr. Harper also is in the camp that says we must eat every 2-3 hours while awake. Not true.
Great challenge- I can’t wait to hear their reply!
I was very interested when I first heard your podcast about the concept of not needing to eat 6 times a day in order to lose weight and keep your metabolism up and it made a lot more sense to me. Although I did lose weight on the 6 meals a day method – I found that I would start to be stressed when working in order to find time to fit all those meals in.
I also read a good article yesterday about fasting that seems to also correspond to the data you have been providing your listeners: http://www.sltrib.com/sltrib/home/51537822-76/fasting-disease-health-cholesterol.html.csp
I’m intrigued by your annoyance. Would you please clarify your stand? You’re against this so-called “myth” — that eating first thing helps you burn calories and your metabolism can slow down?
What are you in favor of then, please? When are you recommending that people have breakfast?
As I recall, when writing about breakfast, I found a number of studies about the benefits of breakfast, but I’m not sure if they cited metabolism burning. (I’ll look later, when I’m off deadline. I’m on deadline for my next book, Beyond Sugar Shock.)
Even if the metabolism burning part were not true, many of us NEED to eat within the first 2 hours of waking. Waiting longer can make people quite hungry so that they make poor chooses, because their blood sugar has dropped so low.
For my part, if I wait longer — and I’ve tested it out — I get a hypoglycemic reaction — headaches, fatigue, confusion, etc. Many people are like that, too.
So, what is it you’re suggesting instead? Thanks.
Connie, as I said above, I’m not against breakfast; I’m against misinformation.
You’re right: Many people find that eating breakfast produces positive benefits. But some people do just fine–nutritionally and otherwise–when they delay or even skip breakfast. Should we force these folks to eat breakfast on the basis of a completely false notion about metabolism, or statistical generalizations?
So, I’m not suggesting anything “instead.” Like you, I’m all for doing what works. But just because something works (for SOME people), I don’t think that gives us license to make up a story about WHY it works. It may seem harmless enough as long as the result is good, but these sorts of myths and misunderstandings can lead to larger errors and misinterpretations. When they take hold in a scientific community, they can even keep us from learning what’s actually going on, which could lead to further understandings. For those reasons, in my opinion, the facts still matter–even if it doesn’t change the actions.
Kudos on a great rebuttal! You’re not only an exceptional nutritionist, but a gifted communicator, debater, and advocate for science and truth. We need more voices like yours in our media.
Have you seen Bob’s body and his proven results??? He does believe in a few meals a day. Nothing wrong with that.. I lost 38 pounds following his advice of eating first thing in the morning and a few smaller meals through out the day. Didn’t excerise or change the food I ate but I did notice I ate less, and consumed less calories because of this.
I now eat something small in the morning when I wake up, and I find at lunch time I don’t need a big meal because I am not straving.. And it wasn’t just me, I know several people that have done the same thing.
Although there is no data (and I haven’t searched) I will take my now size 29 jeans instead of my 33 to 34’s 🙂
By the way, there is no data out there but Baking soda will remove rust using a little arm strength and a toothbrush..
Renee, that’s just it! I’m not questioning Bob’s advice nor his results. I’m questioning his science. As you yourself say, YOU ATE LESS when you started eating first thing in the morning. And that’s the reason that you went from a size 33 to a size 29…not because eating in the morning “revved your calorie burn.”
So what, you may be wondering? It worked! And, indeed, to the person who succeeds, the reasons why probably aren’t important. But to those of us involved with understanding (and explaining) the science of nutrition, it matters very much, for reasons I explain here: https://nutritionovereasy.com/2011/04/why-make-such-a-fuss-about-a-good-habit/
I was inclined to weigh in (no pun intended) with exactly the same comment Monica just posted. So I’ll just echo the comment. It matters why something works or doesn’t because, as I see it, scientific proof of a particular practice means that it should be repeatable in the majority of the population. That’s a whole lot more reassuring and reliable than any one person’s experience. Can you imagine if Ms. Reinagel’s advice was based on an experience one of her friends discussed over lunch? People who eat breakfast, skip breakfast, eat once a day, eat six times a day, all of them can and do lose weight. Almost any significant, peer-reviewed, research that I have ever heard of repeatedly beats the same drum: Proper nutrition combined with sufficient exercise results in weight loss and maintenance and reduce the likelihood of or prevent chronic disease (and make you look and feel better…a plus). I’d throw my lot in with that group.