Reduced metabolism by deficit from nutrition vs. exercise

EvgeniZyntx

When the deficit is lager ? LOL

here's some data from a clinical trial where there are two versions of a 25% deficit - 12.5 exercise and 12.5 less food (CR+EX), or 25 less food (CR) there's also a VLCD on it :-

Thanks for sharing this.

Currently don't have time to read the study so tagging.
My concern is that the predicted TDEE will be based on a weight equation and not an LBM equation.
The branch with exercise will likely lose less LBM and the might explain the differences in prediction versus actual endocrine-driven changes.

meridianova

How do you monitor your TDEE?

I know how much I eat from logging and how much I've lost, so calculate it that way.

(Total calories eaten + pounds lost*3500)/number of days in the time period

i just ran my numbers and came up with something very worrysome... based on that calculation, and compared with the other TDEE calculators available, i'm only burning at 68% efficiency.

my numbers claim that my TDEE is 1,797 per day. i should be at 2,613. so how do i determine what's preventing me from losing weight?

chrisdavey

How do you monitor your TDEE?

I know how much I eat from logging and how much I've lost, so calculate it that way.

(Total calories eaten + pounds lost*3500)/number of days in the time period

THe only issue with that is that you will not lose 100% fat.

stevencloser

Several studies seem to have gotten to similar results:
I was referring to this article proposing some set point theory: jn.nutrition.org/content/127/9/1875S.full

The set point hypothesis never really got any traction, let alone any experimental confirmation.

Then don't call it set point but adaptive thermogenesis My impression is that adaptive thermogenesis is accepted as a fact by many scientists.

Well, that's because it's two different things.
The set point thing was, if I recall correctly, something along the lines of that your body has a certain weight it always wants to go back to if you lose.
Adaptive thermogenesis is your TDEE dropping (slightly, by a few hundred calories at worst as you've seen in the posted screenshots of the studies) after prolonged calorie deficit as a kind of safety mechanism because your body can't tell the difference between actively trying to lose weight and not having enough food to sustain yourself. Which goes back up once you stop being in a deficit.

Scott_2025

Very interesting reading... Thanks everyone for posting.... I have often said losing weight is easy, maintaining weight after reaching goal weight is hard...

bunnylion

Several studies seem to have gotten to similar results:
I was referring to this article proposing some set point theory: jn.nutrition.org/content/127/9/1875S.full

The set point hypothesis never really got any traction, let alone any experimental confirmation.

Then don't call it set point but adaptive thermogenesis My impression is that adaptive thermogenesis is accepted as a fact by many scientists.

Well, that's because it's two different things.
The set point thing was, if I recall correctly, something along the lines of that your body has a certain weight it always wants to go back to if you lose.
Adaptive thermogenesis is your TDEE dropping (slightly, by a few hundred calories at worst as you've seen in the posted screenshots of the studies) after prolonged calorie deficit as a kind of safety mechanism because your body can't tell the difference between actively trying to lose weight and not having enough food to sustain yourself. Which goes back up once you stop being in a deficit.

Yes, you are right. I think there are several takes on both set point and adaptive thermogenesis. I have read that the reasoning behind the set point theory was adaptive thermogenesis. The body adapts metabolism in order to bring you back to your set point or the other way around because of adapted metabolism you return to your set point. An explanation for the set point along these lines was given in the article I posted above.
That's why I threw those two things together, but of course it's better not to do that :-)

yarwell

Currently don't have time to read the study so tagging.
My concern is that the predicted TDEE will be based on a weight equation and not an LBM equation.

It isn't, see the heading "Change in TDEE not explained by change in FM and FFM"

yarwell

THe only issue with that is that you will not lose 100% fat.

isn't that in the use of 3500 already ? (would be >4000 for pure fat)

yarwell

Then don't call it set point but adaptive thermogenesis My impression is that adaptive thermogenesis is accepted as a fact by many scientists.

Adaptive thermogenesis (usually amounts to a candy bar a day) would be one mechanism a set point hypothesis might require to work, for sure.

bunnylion

How do you monitor your TDEE?

I know how much I eat from logging and how much I've lost, so calculate it that way.

(Total calories eaten + pounds lost*3500)/number of days in the time period

Ok, I have been doing the same thing for the past six weeks and so far everything is going as it should :-)
I just want to keep it this way in the long run. From the studies and articles that were posted here it seems that exercise can contribute tremendously. So I'll keep exercise high, keep monitoring TDEE and hope for the best. What more can you do? Fingers crossed!

bunnylion

Then don't call it set point but adaptive thermogenesis My impression is that adaptive thermogenesis is accepted as a fact by many scientists.

Adaptive thermogenesis (usually amounts to a candy bar a day) would be one mechanism a set point hypothesis might require to work, for sure.

And if the study you posted is correct, exercise can help to limit the effects of adaptive thermogenesis and I can keep eating that candy bar. Yay!

bunnylion

THe only issue with that is that you will not lose 100% fat.

isn't that in the use of 3500 already ? (would be >4000 for pure fat)

It was my understanding that the 3500 factors in the energy the body needs to make the >4000 cals of pure fat available where needed? Have to recheck that.

Edit: It seems that body fat only contains 80%-85% of pure fat. The rest being water and other stuff the body binds with fat. So when talking about losing fat free mass is this included? I would imagine that those 15%-20% are considered losing 'water'?

WalkingAlong

With maximal sympathetic stimulation, the MOST you can lose is MAYBE 100 Calories a day.

It is NOTHING in the grand scheme of things,

Steer clear of anyone who starts pushing adaptive thermogenisis.

Do you have any sources for that?

Some might advise readers to steer clear of advice from someone who has an avatar picture of someone else, too.

bunnylion

With maximal sympathetic stimulation, the MOST you can lose is MAYBE 100 Calories a day.

It is NOTHING in the grand scheme of things,

Steer clear of anyone who starts pushing adaptive thermogenisis.

Do you have any sources for that?

Some might advise readers to steer clear of advice from someone who has an avatar picture of someone else, too.

Thank you. :-)

ducati45

I read this article about this :
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3673773/

It seemed to say there was no difference and the weight loss was the most important factor. In fact the conclusion seemed to be that people who had lost a significant amount of weight would be more likely to regain it because their body would perceive them as being Leptin deficient- so they would have far greater hunger cues and feel like they are starving, as well as having a slightly lower energy need to maintain. Your body does work against you! But I'm sure it's not impossible to get back to a state where your body is used to being a certain weight just as it was being a higher weight.
I could be reading it wrong but it seemed to say that it actually got harder to burn more calories in exercise after losing a lot of weight? But yeah, seems like you can't trick your body in to thinking it is not losing fat.

WalkingAlong

But it's also saying that we mainly burn less from activity, not from BMR. And I think it's suggesting that at least part of the reason is the body is less efficient at higher weight and requires more calories to do the same work. Which is kind of intuitive.

"NREE is clearly the compartment of energy expenditure that is most affected by changes in body weight (11, 20) consistent with the importance of physical exercise in the successful maintenance of reduced weight (9, 21)."

I didn't read the leptin part that closely but it just seems like intuitively the body would increase hunger to really difficult levels at low BMI during calorie restriction, not so much when trying to get from 'overweight' to the top edge of 'healthy BMI'.

I think if the body didn't strive for healthful states more often than not we'd be extinct. Striving to have some excess fat makes evolutionary sense. Striving for obesity doesn't.

lemurcat12

How do you monitor your TDEE?

I know how much I eat from logging and how much I've lost, so calculate it that way.

(Total calories eaten + pounds lost*3500)/number of days in the time period

THe only issue with that is that you will not lose 100% fat.

True, and I have various estimates in there too, so it's not perfect. But since I'm using it to monitor changes over time it works fine.