Another Research study on Metabolic rates

SHBoss1673

take a look here http://www.ajcn.org/content/46/4/622.full.pdf+html

titled:
Effects of exercise and food restriction on body compositionand metabolic rate in obese women
conducted by:

James 0 Hill, PhD; Phillip B Sparling, EdD; Toni W Shields, MS; and Patricia A Heller, R


There are some interesting results here. The methods seemed solid to me and the results are further proof of the following theories.
1. If you exercise while in caloric deficit, more of your weight loss is body fat loss than if you don't (see Table 2 and Fig. 2 , average body fat % went down by 2.7% for the exercise group and 1.1% for the sedentary group)

2. If you exercise, you need to account for extra burned calories to keep the body in balance and continuing to lose. (See Fig. 3, for the exercise group, the RMR declined at a continuing rate throughout the 6 week period while after the first 2 weeks the sedentary group stayed essentially constant at RMR). They hypothesize in the study that this is because of (paraphrasing here) the greater difference in calories burned vs. calories eaten (calories eaten wasn't different between groups) and thus the body lowered RMR to keep the calorie imbalance the same.

Number 1 is relatively obvious in it's meaning and needs little further explaination. This has been proven true in multiple studies and thus I take it as simple fact at this point.

In laymans terms, number 2 means (in my observation) that the body is comfortable with a specific calorie deficit, growing the deficit (whether by exercise of simple reduction in calorie intake) makes the body react by lowering how many calories it burns on a regular (non-exercise) basis. This is vital for MFP members to recognize as it proves once again that eating exercise calories will keep your body in a weight loss mode. I.E. if your RMR lowers, then the goal numbers that MFP assumes is no longer correct and what you THINK you should be losing is no longer the case.
The big question is: How big should that deficit be? And that's the hard part to figure out, as we are all so different it makes it super difficult to determine on a generic basis.
discussion?

PattyTheUndefeated

I believe that the less you have left to lose the MORE you should be eating, thus the less your calorific deficit should be. With my own experience, the leaner I got the more my body turned to muscle for fuel as opposed to fat and the weight loss was painfully slow or non-existent on 1200 calorie plan. I've since then switched my calorie goals to maintenance and eat half my exercise calories back. Only now am I starting to see the results I want. When I was big, I started out with a HUGE caloric deficit and never ate my exercise calories and the weight melted off. I believe that the more you have to lose, the more of a (resonable) calorific deficit you can allow yourself to have. It really all depends on what stage of weight loss your in, really.

morganadk2_deleted

Thanks banks

robin52077

Yes! :happy:

Eat those exercise calories!

kidtechnical

Thanks for sharing that. I don't have time right now to go through this with a fine tooth comb, I've had a browse through. My immediate critique would be that the study was tiny and concerned only 8 women. I'd also like to point out that 800 calories a day is okay if you are under constant medical supervision (as these women were, they were inpatients) but would not be recommended for Joe/Jo Bloggs.
I'd love to see this study replicated with a large group, I suspect the findings would be very similar.... although I have to admit, I'm bias & pretty convinced already that eating cals is the way to go.

deandp371

Thanks for sharing that and GO RED SOX! It's gonna be an interesting season...

SoupNazi

Very interesting!

SHBoss1673

Thanks for sharing that. I don't have time right now to go through this with a fine tooth comb, I've had a browse through. My immediate critique would be that the study was tiny and concerned only 8 women. I'd also like to point out that 800 calories a day is okay if you are under constant medical supervision (as these women were, they were inpatients) but would not be recommended for Joe/Jo Bloggs.
I'd love to see this study replicated with a large group, I suspect the findings would be very similar.... although I have to admit, I'm bias & pretty convinced already that eating cals is the way to go.

while I agree that the group is small. You have to look at the methodology in the study. The fact that these women were tested using very precise methods (direct calorimetry is the most accurate way to observe caloric burn as is preserves the total heat exchange and oxygen burn from a closed environment). That being the case, I don't think this type of study, with the level of accuracy of results could be done on a large scale as it's just not really reasonable to be able to do that kind of test with a large group. There have been other studies done with similar results with larger groups, but they are inherently less accurate as they can't do direct observational results. The reason I like this one so much is it actually puts specific numbers with a very small margin for error into readable results. I feel that 8 women is representative enough to account for error, but small enough to monitor efficiently. These results could be duplicated quite easily and I'm sure will be in the future.

beckysiz

I have tried it both ways and as I get closer to my goal weight I find that I NEED to eat those calories. I don't always eat all of them, but I do eat most. I tried not eating them and my weight plateaued. I sat at that same weight for months and I couldn't figure out why... once I started eating them I started losing again.

SHBoss1673

I have tried it both ways and as I get closer to my goal weight I find that I NEED to eat those calories. I don't always eat all of them, but I do eat most. I tried not eating them and my weight plateaued. I sat at that same weight for months and I couldn't figure out why... once I started eating them I started losing again.

you'd benefit from reading another topic I've been posting on as well I think. Well, I mean you might find it interesting as it basically covers exactly what you're talking about.

http://www.myfitnesspal.com/topics/show/158203-why-aren-t-i-losing-anything?page=1#posts-2138274

SHBoss1673

this needs a bump. and I'm just the man to do it!

ladyhawk00

Thanks again, Banks! :drinker:

Azdak

I am going out on a limb here, because I haven't had time to go through this as thoroughly as I wanted. Besides the fact that you have a small sample size, a "niche" group on a metabolic ward, a short-term intervention, and a study that's almost 25 yrs old, I have one caution about over generalizing the results.

Unless I missed something, all of the participants were on an 800-calorie/day diet, which did not increase when they exercised. If I read your remarks correctly, your position is that this study supports the idea of eating back exercise calories based on the fact that the exercise group saw an even greater decrease in RMR.

Obviously, I support that concept in theory, however, in studies like these I think you have to be careful about extending these results to other groups. It could very well be that what we are really seeing is what happens to RMR when you exercise on top of an already low 800 cal/day diet. One might see a different result if, say, you compared groups who were eating 1600 calories per day.

In other words, is it the increased deficit or is it the 800 cal/diet diet? Would one see the same decrease in RMR if the same calorie deficit occurred but the group was at double the intake?

If this is addressed and I missed it, let me know. Thanks for the link, I have saved a copy and plan to analyze the numbers in more detail when I get a chance.

SHBoss1673

I am going out on a limb here, because I haven't had time to go through this as thoroughly as I wanted. Besides the fact that you have a small sample size, a "niche" group on a metabolic ward, a short-term intervention, and a study that's almost 25 yrs old, I have one caution about over generalizing the results.

Unless I missed something, all of the participants were on an 800-calorie/day diet, which did not increase when they exercised. If I read your remarks correctly, your position is that this study supports the idea of eating back exercise calories based on the fact that the exercise group saw an even greater decrease in RMR.

Obviously, I support that concept in theory, however, in studies like these I think you have to be careful about extending these results to other groups. It could very well be that what we are really seeing is what happens to RMR when you exercise on top of an already low 800 cal/day diet. One might see a different result if, say, you compared groups who were eating 1600 calories per day.

In other words, is it the increased deficit or is it the 800 cal/diet diet? Would one see the same decrease in RMR if the same calorie deficit occurred but the group was at double the intake?

If this is addressed and I missed it, let me know. Thanks for the link, I have saved a copy and plan to analyze the numbers in more detail when I get a chance.

That I read, the study didn't make any conclusions about eating calories back. Any exercise calorie hypothesis was mine and this was simply one more research study I've drawn upon to come to my theories. The study pointed out that Assuming a constant calorie intake below the RMR, the body will lower the RMR to compensate, and in the absence of additional energy requirements, will stay there. Exercising simply increased the energy requirements, forcing the body to consequently continue to lower the RMR to balance that out.

My conclusion was simply that, if you stay within that range that the body feels comfortable by giving extra energy, you can continue to lose weight in that "comfortable" zone of calorie deficit without forcing the body to reduce RMR further and make it harder to predict your necessary calories in the future. Added to that is the fact that a larger percentage of weight loss is from Fat mass lost for the group that exercised during the trial.

I understand that this is not a definitive study, and it's a little old, but to that point, indirect calorimetry really hasn't changed much since the 80's. I didn't really see any reason to invalidate the study for age as the methods were sound, and nothing that I could find in the study would necessarily be altered if the study were performed today. With the possible exception of small accuracy increases in the calorimeter machines. But since any variation would be constant for all participants, I don't think that is even an issue in question.

I'm on a continuing mission to provide credible research for the subject of weight loss, nutrition, and overall health. This is just one more piece that we can use.

iamstaceywood

Bump for later.