General chatter - 'Metabolic Advantage' and why the First Law of Thrrmodynamics does not apply




Arctic Mama
01-09-2014, 01:23 PM
I was going to post this elsewhere, but it deserves it's own thread. Highly useful information for any dieter to make an informed choice on their plan.

Excerpt:

So, right off, metabolic advantage or energy inefficiency is known and measurable. Critics of carb restriction as a strategy admit that it occurs but say that it is too small in a practical sense to be worth considering when you are trying to lose weight. These are usually the same people who tell you that the best way to lose weight is through accumulation of small changes in daily weight loss by reducing 100 kcal a day or something like that. In any case, there is a big difference between things that are not practical or have only small effects and things that are theoretically impossible. If metabolic advantage were really impossible theoretically, that would be it. We could stop looking for the best diet and only calories would count. Since we know energy inefficiency is possible and measurable, shouldn’t we be trying to maximize it. But what is the story on thermodynamics? What is it? Why do people think that metabolic advantage violates thermodynamics? What is their mistake? More specifically, doesn’t the first law of thermodynamics say that calories are conserved? Well, there is more than one law of thermodynamics and even the first law has to be applied correctly. Let me explain. (Note in passing that the dietary calorie is a physical kilocalorie (kcal; 1000 calories).

Full blog:
http://feinmantheother.com/2011/06/06/metabolic-advantage-“a-calorie-is-a-calorie”-and-why-the-first-law-of-thermodynamics-does-not-apply-2/


Arctic Mama
01-09-2014, 01:24 PM
Other gems from the post:



The bottom line is that, contrary to what is usually said, thermodynamics does not predict energy balance and we should not be surprised when one diet is more or less efficient than another. In fact, the question to be answered is why energy balance is ever found. “A calories is a calorie” is frequently what is observed (although there is always a question as to how we make the measurement). The answer is that insofar as there is energy balance, it is a question of the unique behavior of living systems, not physical laws. Two similar subjects of similar age and genetic make-up may, under the right conditions, respond to different diets so that most of what they do is oxidize food and the contributions of DNA or protein synthesis, growth, etc. may be similar and may cancel out so that the major contribution to energy exchange is the heat of combustion.

GlamourGirl827
01-09-2014, 08:52 PM
I'm not sure if the following comment is going to make sense in this conversation or just be like of the wall but ..

I was looking up studies regarding diabetics and diet, and there have been studies showing that diabetics on low carb diets not cal restricted lost significantly more weight that those on low cal diets..I know I'm leaving out the details, and not giving my source...if you have access to Medline database for any reason, search it...maybe a googel search will turn up what I'm talknig about. Anyway I'm done with cals in cals out, studies are showing carbs (not fat) as once thought are the culprits behind various diseases like heart disease and high BP...


Arctic Mama
01-10-2014, 06:23 PM
Yes, that is absolutely true and I've looked at some of those studies and their abstracts, myself. That is what the actual blog is about, at least in part - that one of the reasons lower carbohydrate plans cause increased weight loss is the thermic effects of feeding and that, while calories count, the composition of those calories makes a difference in the rate of energy burned and the amount stored.

The human body responds to different nutrients differently - the chemical reactions are just not the same from a Twinkie or a steak, and it is generally more resilient bodies with higher insulin sensitivity that can claim that to be so in any meaningful way. Data, and the strength of that data, is not on the side of "a calorie is a calorie".

mandypandy2246
01-12-2014, 12:32 PM
Totally agree that the data doesn't support a "calorie is a calorie". For metabolically healthy people - it is a close approximation - but for anyone with any sort of metabolic issues (i.e. insulin resistance) it doesnt work anymore.

Annik
01-12-2014, 12:49 PM
I'm not sure if the following comment is going to make sense in this conversation or just be like of the wall but ..

I was looking up studies regarding diabetics and diet, and there have been studies showing that diabetics on low carb diets not cal restricted lost significantly more weight that those on low cal diets..I know I'm leaving out the details, and not giving my source...if you have access to Medline database for any reason, search it...maybe a googel search will turn up what I'm talknig about. Anyway I'm done with cals in cals out, studies are showing carbs (not fat) as once thought are the culprits behind various diseases like heart disease and high BP...

I am one of these people.

Can't really express fully enough how grateful I am that someone broke the code on 'calories in - calories out. ' That theory fails to take the body's hormonal functions into account.

In my case, insulin resistance means I am extremely carb sensitive.

Without taking that into account, weight loss is a real struggle.

I am 51 and have tried many methods. Nothing works for me like a low carb approach.

Annik

Annik
01-12-2014, 12:51 PM
Another good site is here -- link opens to one of many interesting articles about weight loss + low carb approach

http://authoritynutrition.com/how-many-carbs-per-day-to-lose-weight/

mandypandy2246
01-12-2014, 02:06 PM
And contrary what naysayers will say - it doesn't "break" the law of thermodynamics. It's just that the nature of calories in, influences hormones, which then CHANGES the calories out. The standard paradigm treats calroies in and calories out as independent things - whereas, the food in actually influences energy burned.