Is there such as thing as a ‘metabolic advantage’?
Posted on 19 October 2009
Last Friday my blog focused on a study which found that fat intake (total fat, as well as levels of, saturated, unsaturated and polyunsaturated fat) appeared to have no impact on change in body weight over a period of several years. Partly in an attempt to explain how this can be so, I outlined the biochemical basis of the accumulation of fat in the fat. Several biochemical truths point to an excess of carbohydrate as a major driver of obesity. This throws up the possibility that a diet high in fat but low in carbohydrate might affect weight in a way that is independent of calories.
The idea that a particular diet might have weight loss benefits that cannot be predicted utterly by the calories contained in that diet is often referred to as
Published October 19, 2009 . Filed under: Diabetes/Metabolic Syndrome, Healthy Eating, Low-Carbohydrate/Carbohydrate Restriction, Weight Loss
After years of people saying “where are all the low-carbers” in the National Weight Control Registry, the first post-Atkins craze cohort appeared in 2007. http://www.ncbi.nlm.nih.gov/sites/entrez?Db=pubmed&Cmd=ShowDetailView&TermToSearch=17925473&ordinalpos=2&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVDocSum
The interesting thing is that it gives strong support to the metabolic advantage hypothesis. The low-carbers report that they eat about 500 calories a day more and exercise 1000 calories a week less (than calorie restricted individuals) for the same weight maintenance. The 4500 calories a week difference (more than a pound of fat-energy) is hard to explain without metabolic advantage.
October 19, 2009 @ 10:01 pm
Of mice and (wo)men.
Mice:- “The results showed that the high-fat, low-carb diet led to a significant enhancement in total energy production. This appeared to explain where the
October 19, 2009 @ 10:21 pm
Nigeepoo
“~3% of dietary fat Calories are lost due to increased total energy production. This isn
October 20, 2009 @ 12:27 am
“Could it be that making fuel (including fatty acids) more readily available in the body will enhance metabolism through increased activity?”
It is certainly true in my case. Since being on a low carb diet, I have more energy. So I exercise more. Not because I think it is good for me but because I have to do something with that energy.
October 20, 2009 @ 12:57 am
Jake
Thanks for sharing your experience.
Very rarely, in my experience, does someone on a carb-controlled diet not experience enhanced energy, and a natural tendency to move more as a result.
October 20, 2009 @ 1:03 am
Here is a double blind randomised studie (free full text) that seems to indicate that some types of food gives a metabolic advantage.
In this case they compared Medium Chain Triglycerids (which you can find a fair bit of in coconut oil) to Olive oil. It turned out that on same caloriec intake, the people with added MCTs lost statistically significantly more weight than the people with added olive oil.
http://www.ajcn.org/cgi/reprint/87/3/621
October 20, 2009 @ 2:12 am
I’m one of those that has lost over 3 stone, kept it off, and done so by eating meat/fat indiscriminantly while eliminating sugar, reducing fruit to 1-2 servings/day, and reducing starch (potato/rice) to 2 servings/week.
I used to be a die-hard low carb believer, and thought that all carbs were the devil, and that you’d never store fat without them. Not so.
You can store fat as fat. The issue is not where the calories are stored, the issue is if the stored calories are released. Chronically elevated insulin levels inhibit the release of fat from adiposites. If you eat a whole lot of fat, you’ll store plenty of it as fat, but the release of fatty acids into the blood for use as energy will go on, relatively uninterrupted by insulin.
Again, it’s not that carbs are stored as fat (though they certainly can be) that’s the problem. It’s that carbohydrate, in a person with metabolic syndrome, prevents fat from being released.
October 20, 2009 @ 2:38 am
Hi Dr. Briffa,
Check this study out. Not only does it show that butter and coconut oil won’t cause fatty liver in rats like corn oil does, it also demonstrates the metabolic advantage in a major way.
“Rats fed coconut (86% of saturated fatty acid) or butter (51% of saturated fatty acid) had an increased caloric intake (+143% and +30%). At the end of the study period, total lipid ingestion in term of percentage of energy intake was higher in both coconut (45%) and butter (42%) groups than in the standard (7%) diet group. No change in body mass was observed as compared with standard rats at the end of the experiment.”
Coconut fed rats did have a significant increase in fat mass, but it didn’t even come close to accounting for a 143% increase in calorie intake over 14 weeks. They burned more energy spontaneously, due to more brown fat and more uncoupling proteins.
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1805500/
October 20, 2009 @ 6:57 am
Thras said:
“…The low-carbers report that they eat about 500 calories a day more and exercise 1000 calories a week less (than calorie restricted individuals) for the same weight maintenance. The 4500 calories a week difference (more than a pound of fat-energy) is hard to explain without metabolic advantage.”
The problem with studies where food intake isn’t rigorously controlled by the researchers is:-
a) People are hopeless at estimating portion sizes, even if they use scales. See
http://www.youtube.com/watch?v=JVjWPclrWVY
b) Food labels aren’t particularly accurate. See
http://www.muscletalk.co.uk/article-food-composition-analysis.aspx
c) People who feel like they’re eating plenty will tend to overestimate their food intake compared to people who feel like they’re deprived.
When push comes to shove, a Calorie is a Calorie only where weight is concerned. Where anything else is concerned e.g. body composition, health, wellbeing etc, the source of those Calories does make a difference.
P.S. In post No. 2, I should have written “This can lead” instead of “This leads”, as everyone is different.
P.P.S. I can confirm that Coconut oil raises metabolic rate thus increasing Calories out in the energy balance equation. I have secondary hypothyroidism (zero TSH) and taking Coconut oil in 2002 raised FT4 from 9.8pmol/L to ~15pmol/L.
October 20, 2009 @ 9:24 am
Nigeepoo
“When push comes to shove, a Calorie is a Calorie only where weight is concerned. Where anything else is concerned e.g. body composition, health, wellbeing etc, the source of those Calories does make a difference.?”
I don’t necessarily agree with the first statement, but the second point is very important – generally there’s too much emphasis on weight loss, I think, and not enough on changes in body composition.
“taking Coconut oil in 2002 raised FT4 from 9.8pmol/L to ~15pmol/L”
Did you lose any weight?
October 20, 2009 @ 10:26 am
Nigepoo,
I’m interested in the effects of low T3 on the body as my recent blood tests point to a deficiency in this regard. I read Jenny’s article on weight loss stalling and wasn’t convinced. I lost 33 kg in 14 months with a low carb diet and I’m still losing albeit much slower obviously, without counting calories. Regarding Lyle McDonald’s book, I read the paragraph referred to (google books) and he concludes by saying that low T3 in the euthyroid syndrome does not influence the metabolic rate. He talks about a threshold of 50 grams of carbs a day to avoid the decrease in T3. I’m going to check the references starting on page 49 when I have time.
Could dr. Briffa comment on this?
October 20, 2009 @ 2:13 pm
Dr John Briffa said:
I don
October 20, 2009 @ 3:54 pm
Nige,
I don’t know. It’s hard to say as it wasn’t measured previously. According to the doctors I saw I’m not hypothyroid, my TSH is not even elevated and my T4 is within range. I’m not cutting calories, I’m not on a ketogenic diet either, and I don’t know of other causes, besides maybe stress or mineral deficiency. Hypothyroidism and euthyroid syndrome are two different things.
October 21, 2009 @ 7:25 pm
Hi simona,
Something’s affecting your conversion of T4 to T3. Stress is a possibility. Have you had cortisol tested? As you’re not on a ketogenic diet, Lyle’s comments don’t apply so the lack of T3 could be reducing your metabolic rate.
If your FT3 is below the Reference Range, I would say that you *are* technically hypothyroid. However, I’m not a doctor. Awaiting Dr Briffa’s input.
Cheers, Nige.
October 21, 2009 @ 8:49 pm
John,
Is the increased fat in the mouse study ‘natural’ (animal products – fat/butter (sat/mufa)), or ‘manufactured’ (vegtable oils (pufa))?
Dave
October 22, 2009 @ 9:53 pm
David
Fats used in the ketogenic diet and the percentage of the weight of the diet contributed by them were:
lard – 47.5 per cent
butter – 19.95 per cent
vegetable oil – 11.4 per cent
October 22, 2009 @ 10:54 pm
Hi Simona -
Has your doctor prescribed a blood test to ascertain you do not have an autoimmune disorder called Hashimoto’s Thyroiditis? I had normal thyroid tests, however, I also had the usual symptons associated with low thyroid. I did some research on line and found an article on Hashimoto’s. I then asked my endocrinoglist to order a blood test to measure antibodies. Sure enough, they were very, very high. I am now on Synthroid + free T3 and all symptoms are gone. I also have a new endocrinologist.
Cheers from sunny California, Gabriella
October 23, 2009 @ 8:02 pm
in all this debate about low-carb, I’d like to know the definition of low-carb. Is it low-glycemic carb –which has plenty of carbs, but of the slow release variety and hence without the insulin spike?
October 23, 2009 @ 8:05 pm
Hi there Simona,
Please be aware that the common usage of TSH as an inflection on metabolic status of tissues is fallacious and there is no evidence supporting its use. (see fraser paper BMJ)
A recent nature review concludes that serum levels of thyroid hormones cannot be used to infer tissue levels.
Applying the commonly used tests for assessing thyroid hormone sufficiency are subsequently inadequate in addition to being scientifically indefensible. In your instance you may have levels within ‘ranges’ but still suffer from inadequate thyroid hormone regulation.
Furthermore the available evidence suggests inhibition of T4 to T3 by cortisol only lasts for a number of weeks.
As its late i havent been able to locate the two papers touched upon earlier.
October 25, 2009 @ 2:06 am
Thank you all for replying
The consultant pathologist mentioned the antibodies, I suppose it’s going to be there once I see the results. My GP sent me to him because I had sky high LDL levels that doubled in a year of low-carbing. (maybe just coincidence, maybe not) They (the junior doctor taking my case history, the pathologist and the other doctor there, maybe an endocrinologist) are trying to say that it’s the diet and the weight loss that lowered my T3, and all that sat fat that raised my LDL. I don’t agree. I gave them the whole list of symptoms associated with hypothyroidism but they don’t want to know (hairloss, dry skin, feeling of cold, acne, menstrual problems, tiredness, depression) Two days ago, I received an appointment card to see a dietician. I didn’t even requested it, why would I, so they can tell me to eat vegetable oil, no eggs and no butter?
I said I would like to have an NMR done and all the hormones including cortisol. He said they don’t do lipid subfractionation. We’ll see how it goes, but I’m not very hopeful.
October 31, 2009 @ 12:19 am
Hi again simona.
Is your GP not going to do *anything* about your low FT3? No Cytomel? I think that you should argue the case for treatment.
Regarding LDL, you’re stuck between a rock and a hard place because you can’t get lipid subfractions tested, so you don’t know how much type A vs type B LDL you have. You could try switching from sat to mono fats to see if it reduces your LDL, just to get the medics off your back.
In the meantime, to improve your mood, you could try supplementing with 5,000iu/day Vitamin D3 and shed-loads of oily fish. I’ve just blogged about it. Vitamin D3 also helps with autoimmune problems.
Cheers, Nige.
November 1, 2009 @ 1:28 pm
Update: See I have a theory.
January 8, 2010 @ 3:49 pm
See also Enzymes
January 16, 2010 @ 6:39 pm
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