Paleo Diet and Paleolithic Diet Questions & Answers

Question

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Sucrose substitution in prevention and reversal of the fall in metabolic rate accompanying hypocaloric diets

Hypocaloric diets cause a fall in resting metabolic rate that interferes with weight loss. To evaluate the mechanisms underlying this phenomenon, resting metabolic rate was measured sequentially in six healthy obese women on a weight maintenance diet (more than 2,300 kilocalories), after 15 days of an 800 kilocalories carbohydrate-free diet, and after isocaloric sucrose replacement for an additional 15 days. The carbohydrate-free diet produced a 21 percent decline in resting metabolic rate (p <0.005) as well as a decrease in circulating triiodothyronine (41 percent, p <0.02) and insulin (38 percent, p <0.005) concentrations. Plasma norepinephrine levels also tended to decline (10 percent, 0.05> p <0.1). However, when sucrose was substituted, resting metabolic rate rose toward baseline values even though total caloric intake was unchanged and weight loss continued. The sucrose-induced rise in resting metabolic rate was accompanied by a rise in serum triiodothyronine values, but not plasma insulin or norepinephrine concentrations. Throughout, changes in resting metabolic rate correlated with changes in serum triiodothyronine levels (r = 0.701, p <0.01). In four obese women, a hypocaloric sucrose diet was given at the outset for 15 days. The fall in both resting metabolic rate and triiodothyronine concentration was markedly reduced as compared with values during the carbohydrate-free diet. It is concluded that carbohydrate restriction plays an important role in mediating the fall in resting metabolic rate during hypocaloric feeding. This effect may, at least in part, be related to changes in circulating triiodothyronine levels. Incorporation of carbohydrate in diet regimens may, therefore, minimize the thermic adaptation to weight loss.

http://www.amjmed.com/article/0002-9343%2886%2990264-0/abstract

flag	asked Jan 27 2012 at 17:31 cliff 13.4k●1●9●28

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Is this a question or just the abstract of an article? – PrimalDanny Jan 27 2012 at 18:18

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I'm not saying sugar is bad, but eating 800 calories a day means the study is flawed from the start. If they're so worried about the metabolism slowing down then they should be fasting. Eat a large 2400 once every 3 days, instead of 800 everyday. – Ratiocinative Jan 27 2012 at 18:56

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If grains are so bad, why do they raise metabolism? – PrimalDanny Jan 27 2012 at 19:00

@Ratiocinative- Where is your study supporting your statement that eating 2400 calories once every 3 days will keep metabolism at baseline levels? – cliff Jan 27 2012 at 19:14

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I'm sorry, but that says essentially nothing. Are you trying to argue that grains are therefore good? Are you trying to qualify your original 'question'? Can't you start a blog to post cryptic non-statements about abstract biology and links to carefully selected studies? – PrimalDanny Jan 27 2012 at 19:25

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Paul Jaminet · Answer 1 · 2012-01-27 18:14:54Z UTC

Cliff, you have to distinguish between the effects of carbs on the one hand, and the differential effects of sugar v starch on the other.

As I've blogged (eg http://perfecthealthdiet.com/?p=4383), zero-carb diets invoke a glucose conservation program that downregulates T3 thyroid hormone level and metabolism. Restoring carbs in any form will restore T3 levels and metabolic rate. Starch works as well as sugar. That effect is all this study shows.

In this case "raising metabolism" was beneficial but not every dietary change that raises metabolism will be. Excess calories / overfeeding will raise the metabolism but is not a healthy practice over any extended period of time.

None of this supports a preference for fructose-bearing sugars over other types of carbohydrate.

luckybastard · Answer 2 · 2012-01-27 18:23:32Z UTC

hmmm...maybe so you can burn it off quicker to get it out of the body?

I think something's being lost in the big picture here. I'm not a sciencey type which puts me at a disadvantage in some ways, but it also gives me a more simplistic bigger picture view. I'm a fan of keeping things that are blatantly toxic out of the body, however, there are many things that fall into a gray are of being toxic at high doses- granted that doseage may be higher or lower for individuals. I put fructose in that category. From where I stand, the body can deal with it in small and even moderate amounts- particularly from fruit where it's usually attached to glucose. When we start talking about ingesting large amounts of juices from fruit- much more than we can find in nature- my first question is why? I'm not asking that rhetorically, I really want to know the benefit of doing so. I've heard the argument that it takes care of the morning cortisol spike. Why would I want to do that? I've heard that it replaces liver glycogen. Well so does excess glucose from starches after your muscles have been loaded up with glycogen. These arguments just aren't strong. Yes, I know that PUFA's compound the problem but I'd like to see at the least an epidemiological study of a group of people living on a high fructose diet and thriving. Outside of that, I would proceed with caution with the biohackers claiming that fructose in high doses is benign...

Edit: I also want to challenge the assumption that an elevated metabolism is always a good thing. From where I stand, metabolism is something that varies for a reason- it regulates the energy balance. Is there a reason I would want my truck idling at 2500rpm? I wouldn't want my body to either.

Travis Culp · Answer 3 · 2012-01-27 17:40:23Z UTC

If I'm not mistaken, the activity of hepatic deiodinase (which converts T4 to T3) is downregulated when liver glycogen drops below a particular threshold. As such, carbohydrate restriction behaves in a very similar manner to a selenium deficiency, with the result being far less active thyroid hormone, even if T4 is at a normal level.

raydawg · Answer 4 · 2012-01-27 17:49:17Z UTC

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Simple. It triggers insulin after a certain level in the blood, beyond which it becomes toxic to nerves, eyes, etc. Insulin, in turn, triggers storage of nutrients to fat.

answered Jan 27 2012 at 17:49

raydawg
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"The sucrose-induced rise in resting metabolic rate was accompanied by a rise in serum triiodothyronine values, but not plasma insulin or norepinephrine concentrations." – Travis Culp♦ Jan 27 2012 at 18:00

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Why do people upvote this? he clearly didn't even read my post. – cliff Jan 27 2012 at 18:36

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@Cliff Meth-Amphetamine, as well as 2,4-Dinitrophenol also raise metabolic rate, but they are certainly not something you'd want to take. Why do you feel that if something raises metabolic rates is an indicator of it not being bad? The insulin effect is still there after you go past a certain threshhold. – raydawg Jan 27 2012 at 22:12

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@cliff - butter?? But it lacks n6... – nick Jan 28 2012 at 19:31

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Sugar crystals are as natural as butter... – JRAC Jan 29 2012 at 13:50

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PrimalDanny · Answer 5 · 2012-01-27 18:24:34Z UTC

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If sugar is so bad, why does it raise metabolism?

Because raising metabolism is bad? This seems to beg the question, not to mention take a grossly simplified approach that will likely confuse many people. There's so many other questions that could be asked to try and clarify the point that it would be easier if you could be mroe specific about the problem you're needing help with.

answered Jan 27 2012 at 18:24

PrimalDanny
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How is raising metabolism(thyroid) bad? – cliff Jan 27 2012 at 18:33

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I'm sorry if you found this answer unhelpful, but as I said, you're just begging the question, seemingly because you want to argue with everybody. Raising the metabolism burns through resources faster. With limited resources, this may be a bad idea. I realise you may have very strong beliefs to the contrary, but that doesn't meanyou have to be blind to another point of view. Why is raising metabolism good? – PrimalDanny Jan 27 2012 at 18:47

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I don't want to argue with anyone I want to expand people's realities to be more in line with truth. – cliff Jan 27 2012 at 19:19

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With your truth. – PrimalDanny Jan 27 2012 at 19:26

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Still, from an objective viewpoint, if your aim is to educate/convert people then you don't seem to be going about it in the best way. There's so little rigour and so much assumption that it really is very easy for people to dismiss your points if they have a mind to whether they are valid or not. You never seem to listen or actually respond to what other people have to say if it's critical - that might be a good place to start. – PrimalDanny Jan 27 2012 at 19:29

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No more. · Answer 6 · 2012-01-27 18:12:17Z UTC

Sugar raises metabolism because it bypasses the most important control points in glycolysis (Glucokinsae and PFK-1. The product fructose turns into for glycolysis Fructose 1,6 bis phosphate stimulate the one remaining pathway). Whether the rise of metabolism is a good or a bad thing is dependent on many factors but most importnatly nutritional status. If people aren't nutritionally replete, they may not have the nutrients necessary for a high metabolism but the consumption of fructose will cause them not to be able to regulate energy production as tightly which will call for the use of precious nutrients.

coprophagous · Answer 7 · 2012-01-27 17:47:49Z UTC

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the amount of sugar in just one can of coke is enough sugar to lower the metabolism of infection fighting blood cells by 75 percent. http://www.natural-pain-relief-guide.com/sugar-immune-system.html

edited Jan 27 2012 at 17:47

answered Jan 27 2012 at 17:39

coprophagous
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And what do this have to do with the question at hand? – Matt Jan 27 2012 at 18:25

You linked me to a whole bunch of opinions. – cliff Jan 27 2012 at 18:37

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It is good to cite sources for claims, this article isn't a verifiable source and provides no citations. Luckily I know of the paper that people who say this refer to ajcn.org/content/26/11/1180.full.pdf+html It does appear that after sucrose phagocytosis is less effective than after starch. Not by 75% though, that's an arbitrary number. I don't know a lot about this stuff, there could be other factors at play that make this not so. I asked Paul to take a look at the issue but he has a lot to do already so I don't have any answers yet. – Stabby Jan 27 2012 at 18:50

That's like saying because protein is bad for people in kidney failure protein CAUSES kidney failure in healthy people. I don't have a system infection or chronic pain (natural-pain-relief?) – Just Mike Feb 1 2012 at 19:55

my goal is to get everybody to read the link. you dont have to like the link but it will go down with a spoonful of sugar. – coprophagous Feb 3 2012 at 0:19

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If sugar so bad why does it raise metabolism?

7 Answers