Another gem from Levine and the Mayo Clinic (just sent to me by Doug Kalman).

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Weekly Changes in Basal Metabolic Rate with Eight Weeks of Overfeeding

Ann M. Harris, Michael D. Jensen and James A. Levine

Endocrine Research Unit, Mayo Clinic, Rochester, Minnesota.

Address correspondence to James A. Levine, Endocrine Research Unit, 5-194 Joseph, Mayo Clinic, 200 First Street, SW, Rochester, MN 55905. E-mail: [email]levine.james@mayo.edu[/email]

Objective: The contribution of basal metabolic rate (BMR) to weight gain susceptibility has long been debated. We wanted to examine whether BMR changes in a linear fashion with overfeeding. Our hypothesis was that BMR does not increase linearly with 1000-kcal/d overfeeding in lean healthy subjects over 8 weeks. The null hypothesis states that BMR increases linearly with 1000-kcal/d overfeeding in lean healthy subjects.

Research Methods and Procedures: Initially, 16 lean healthy sedentary subjects completed 2 weeks of weight maintenance feeding at the General Clinical Research Center. The subjects were then overfed by 1000 kcal/d over 8 weeks. BMR was measured under standard conditions each week using indirect calorimetry.

Results: Baseline BMR was 1693 ? 154.5 kcal/d. BMR increased from 1711 ? 201.3 kcal/d at week 1 of overfeeding to 1781 ? 171.65 kcal/d at the second week of overfeeding (p = 0.05). BMR fell during the third week of overfeeding to 1729 ? 179.5 kcal/d (p = 0.05). After 5 weeks of overfeeding, BMR reached a plateau. Thereafter, there was no further change. Comparison of BMR with weeks of overfeeding was significantly different compared with the linear model (p < 0.05).

Discussion: Increases in BMR in lean sedentary healthy subjects with 1000-kcal/d overfeeding are not linear over 8 weeks. There seems to be a short-term increase in BMR in the first 2 weeks of overfeeding that is not representative of longer-term changes.
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This study lends more evidence to the idea that BMR metabolic rate scales with overfeeding and calorie expenditure chases calorie intake. However, as you see, per 1000kcal overfeeding, BMR increases by about 100kcal. That may not seem like much however TEF and NEAT will increase as demonstrated here:

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Role of nonexercise activity thermogenesis in resistance to fat gain in humans.

Levine JA, Eberhardt NL, Jensen MD.

Department of Medicine, Endocrine Research Unit, Mayo Clinic and Mayo Foundation, 200 First Street Southwest, Rochester, MN 55905, USA.

Humans show considerable interindividual variation in susceptibility to weight gain in response to overeating. The physiological basis of this variation was investigated by measuring changes in energy storage and expenditure in 16 nonobese volunteers who were fed 1000 kilocalories per day in excess of weight-maintenance requirements for 8 weeks. Two-thirds of the increases in total daily energy expenditure was due to increased nonexercise activity thermogenesis (NEAT), which is associated with fidgeting, maintenance of posture, and other physical activities of daily life. Changes in NEAT accounted for the 10-fold differences in fat storage that occurred and directly predicted resistance to fat gain with overfeeding (correlation coefficient = 0.77, probability < 0.001). These results suggest that as humans overeat, activation of NEAT dissipates excess energy to preserve leanness and that failure to activate NEAT may result in ready fat gain.
***

In other words, as we overfeed, metabolic rate increases through a variety of mechanisms (BMR, TEF, NEAT).

However, our metabolic upregulation isn't universal. In fact, there is a huge variation. Some subjects upregulate very well while others do not. In fact, in one study, the fat gain variation over 8 weeks of 1000kcal surplus was from 0.5lbs of fat gained to 10lbs of fat gained. In other words, some individuals will overfeed and gain huge amounts of fat while others won't gain a pound.

In my G-Flux seminar series, I discuss why this is the case and what you can do if you're the type who gains huge amounts of fat with overfeeding.

In the end, this just shows how important it is to individualize your intake based on your response. So if you're not measuring your body comp regularly and adjusting accordingly (as we teach you to do in our Precision Nutrition program), you're groping blindly in the dark. Good luck with that.

It also goes to show how important G-Flux. G-Flux is the secret to better body weight regulation. Those individuals who regulate poorly (gain lots of fat with overfeeding) need to substantially boost G-Flux.

Well, as the emails are already coming in, a mere few minutes after putting this up, I figured I'd do a preemptive response.

I may be willing to do another G-Flux seminar if the interest is there.

Any votes for a Toronto G-Flux seminar?

Interesting.

Are there any studies on the opposite? The effect on BMR by restricting calories by 1000 per day?

Thanks JB.

Please keep posting abstracts and/or articles such as these, they are very informative.

Question

Do you expect the plateau (after ~5 weeks) mentioned in the first abstract to be temporary (a few weeks) or longer term before your body further raises BMR.

Depending on your theories this could be a good article idea - "BMR Plateau Busting Strategies"

hmmm, interesting information. In your opinion then, could differences in somatotype (endo/exo/mesomorph) be somewhat attributable to ones ability to activate NEAT in response to overfed conditions?

I also find it interesting that BMR only upregulates for about 2 weeks, is there any evidence to suggest NEAT response might follow a similar trend in those who accumulated larger amounts of fat over the 8 week period? Given the information presented, what suggestions might you make for planning a successful bulk with minimal fat gain? For example, could there perhaps be a benefit in planning two week overfeeding periods every 4-6 weeks or so (combined with an increased volume approach) for maximal lean mass /minimal fat gain?

Why not Montreal?!
What do you think about Poliquin's Biosignature thing?

I live near Toronto in the Fall of 06!!! (school in St. catharines)

That's some very interesting data.

Does it suggest a sort of caloric cycling plan with the goal of pushing the metabolic rate higher and higher?

any chance there will be a follow-up to your first G-Flux article, not sure if I can make it to a seminar unfortunately.

Not sure if another article is possible though.

Thanks, Matt

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I'm trying to shed fat right now and I will get to 6% BF (no matter how long it will take). Using many of your advices and your 90% addherence (at the beginning, I was struggling to get 90% and now, I'm 100% clean and have no trouble to say no to a big chocolate cheesecake & pizza & fries). Now, I've always accumulated fat more on the lower body (thighs & glutes, especially... yeah, like a woman :(.

From what I understood from Mr. Poliquin, this mean I should:

1) eat a lot of broccoli

2) use topic cream Yohimbine (I use an oral form in my thermogenic stack) and

3) eat plenty of soya.

I've read so many bad things about soy, some coming from you... What do you think? Will my fat accumulation parts will progressively melt off or should I follow those advices? What quantity is optimal for a 200+ pound man (soy and yohimbine)?
Thanks, I really appreciate your work.