27 June 2012

Study Finds that Carbs Prevent Energy Use


Supports Chapter 19: 'Healthy eating' is fattening

A few days ago, England’s Euro 2012 football team lost a quarter-final match to Italy on penalties. This scenario has happened so regularly that one might call it the ‘England finish’.

It has also happened so regularly that it hasn’t been difficult to see a pattern emerging for some years: England just run out of energy; they aren’t able to sustain 90 minutes of football.

The question is: Why? And the answer, which I have been convinced of for some years, was their rubbish carb-based diet. I am no lover of football, so have never watched a game, but commentaries on news bulletins spell out the form. To précis it, the England team always seem to start the game full of bounce, have most of the possession and often take the lead, then I all goes wrong. At half time they fill up on Jaffa cakes - and are so rubbish during the second half that they lose. But this, is exactly what I would expect. Carbs not only result in reactive hypoglycaemia (you run out of blood glucose), they also raise serotonin, a hormone that makes you sleepy and slows you down. This is why people are advised to have a carb meal before going to bed. But both of these conditions are the last thing you should eat if you have to work – or play football.

Now a study just published in the Journal of the American Medical Association finds another good reason why the carbs, so favoured by the England team’s nutritionists, are so devastating to their game: Carbs, it now appears, as well as everything else that is wrong with them, actively slow down the rate at which your body can use its energy.

Here is the abstract of the study – and an explanation as it is a bit convoluted:

Ebbeling CB, et al. Effects of Dietary Composition on Energy Expenditure During Weight-Loss Maintenance. JAMA 2012;307(24):2627-2634

ABSTRACT
Context Reduced energy expenditure following weight loss is thought to contribute to weight gain. However, the effect of dietary composition on energy expenditure during weight-loss maintenance has not been studied.

Objective To examine the effects of 3 diets differing widely in macronutrient composition and glycemic load on energy expenditure following weight loss.

Design, Setting, and Participants A controlled 3-way crossover design involving 21 overweight and obese young adults conducted at Children’s Hospital Boston and Brigham and Women’s Hospital, Boston, Massachusetts, between June 16, 2006, and June 21, 2010, with recruitment by newspaper advertisements and postings.

Intervention After achieving 10% to 15% weight loss while consuming a run-in diet, participants consumed an isocaloric low-fat diet (60% of energy from carbohydrate, 20% from fat, 20% from protein; high glycemic load), low–glycemic index diet (40% from carbohydrate, 40% from fat, and 20% from protein; moderate glycemic load), and very low-carbohydrate diet (10% from carbohydrate, 60% from fat, and 30% from protein; low glycemic load) in random order, each for 4 weeks.

Main Outcome Measures Primary outcome was resting energy expenditure (REE), with secondary outcomes of total energy expenditure (TEE), hormone levels, and metabolic syndrome components.

Results Compared with the pre–weight-loss baseline, the decrease in REE was greatest with the low-fat diet (mean [95% CI], –205 [–265 to –144] kcal/d), intermediate with the low–glycemic index diet (–166 [–227 to –106] kcal/d), and least with the very low-carbohydrate diet (−138 [–198 to –77] kcal/d; overall P=.03; P for trend by glycemic load=.009). The decrease in TEE showed a similar pattern (mean [95% CI], −423 [–606 to –239] kcal/d; −297 [–479 to –115] kcal/d; and −97 [–281 to 86] kcal/d, respectively; overall P=.003; P for trend by glycemic load<.001). Hormone levels and metabolic syndrome components also varied during weight maintenance by diet (leptin, P<.001; 24-hour urinary cortisol, P=.005; indexes of peripheral [P=.02] and hepatic [P=.03] insulin sensitivity; high-density lipoprotein [HDL] cholesterol, P<.001; non-HDL cholesterol, P<.001; triglycerides, P<.001; plasminogen activator inhibitor 1, P for trend=.04; and C-reactive protein, P for trend=.05), but no consistent favourable pattern emerged.
Conclusion Among overweight and obese young adults compared with pre–weightloss energy expenditure, isocaloric feeding following 10% to 15% weight loss resulted in decreases in REE and TEE that were greatest with the low-fat diet, intermediate with the low–glycemic index diet, and least with the very low-carbohydrate diet.
What it means
This is a study looking at weight loss, but in a different way from normal. Usually, scientists look at the amount of weight lost and/or for how long. This one is different; here they are considering how the different macronutrients affect energy usage. To make it confusing, the authors don't talk about energy usage, they talk in terms of 'decrease' in amount of energy used.

The study looks at two aspects of energy usage. A person has to use a certain amount of energy just to keep their body alive: These are things like the heart beating, brain working, keeping the body warm, etc, which they call “resting energy expenditure” (REE). This is relatively constant at approximately 1,500 kcals for an average-sized person. On top of that is the amount of energy we use when we do work or exercise. The total of the two is the total energy expenditure (TEE).

Here we have three different diets with same amount of calories, but with different ratios of carbs, proteins and fats. In this respect it is similar to the Dunlop & Lyon study of 1932 and Kekwick & Pawan’s 1956 study, both of which found that the lowest carb diet was the best for weight loss. With a similar finding, this latest study tells us why. When they ate the 60% carb diet, the participants used the least energy. It even cut the amount of energy used to maintain the body (REE). The diet on which they used the most energy (both REE and TEE) was the diet which had the least carbs and most fats.

Diet and exercise
So, if you are counting calories and exercising to lose weight, as the ‘experts’ say you should, then, obviously, when you exercise, you want to use as much energy as possible. There isn’t much point in jogging lots of boring miles if you are not going to use up energy – and thus weight - right? But this study shows that if you eat the diet these incompetent ‘experts’ advise you to eat, you won’t lose as much as you would if your diet was high-fat, low-carb!

And if you are an England footballer, you really don’t want to have to eat a diet that destroys your ability to use all your energy. Or a nutritionist/dietician who insists on it!

22 comments:

Amanda Turner said...

I do love Jaffa cakes... but I know that a breakfast of bacon and eggs cooked in butter will allow me to climb a mountain and come back down again without any problems. Trick and Treat is the best book I ever read.

Ian said...

Hi Barry,

I've read all your books by the way.

I just wondered if you've read yesterday's article on the front page of the Daily Express:
http://www.express.co.uk/posts/view/329161/Heart-attack-risk-in-dieting

Regards, Ian

Barry Groves said...

Hi Ian

his study is quite ridiculous, and the Express's coverage of it, scandalously misleading. Here's why

1. The participants filled in a questionnaire about their diet just once 12 years before the follow-up.

2. The hazard ratios (harm vs benefit are so close to 1.0 that the result is not statistically significant.

3. The 'harm' is only increased for high protein intake, but a proper low-carb diet is NOT high protein, it is bigh fat.

4. Even so, the study's figures allow us to calculate that if you are a woman between 30 and 50 your chance of NOT dying from a heart attack in the next 12 years if you eat their low-carb, high-protein is 99.58%, but if you eat low protein high carb (which they say is healthier, you can increase your chance to 99.87%. That's an increase of a whole 0.28%!!!

5. Lastly, according to a previous paper from the same group they excluded anyone with any kind of disease, which means they have obviously excluded diabetics - the people who most benefit from a low-carb diet!

The whole thing is nonsense.

Barry Groves

Anonymous said...

Dear Barry
I am a geneticist with a Phd and I ahve been practicing paleo/lchf for the last seven months now. I cannot believe the results and I am going to stick with it as I never felt/looked more healthy in my life. I have read extensively on the lchf tiopic including your very good provocative book Trean and treat which I recommend to everybody I know.
But I cannot agree with how you apply this latest confirmation that low carb is better for you to England's demise in the EUFA cup. Do you perhaps think that other teams, Italy for example have jars or lard or scrambled eggs at half time? I think MOST of modern competitive athlete eat hig carb because this is what their trainers believe and have been told etc. so one team of carb junkies (England) were mere facing another team of carb junkies and when it comes to penalties it is really pot luck. SO unless you know for certain that a given team has adopted a lchf regime for their athletes you cannot say that England lsot because of the jaffa cakes they scoff at half timeI can see all of the players independently of team/nationality guzzling down sugary gathorade by the gallon! They are all carb addicts so at least on that basis are on equal footage.....Assuming comparable carb intakes by the two teams..Italy was a far superior team! No diet can change that although I agree that it would be nice to see athletes in general pushing the boundaries of human endurance on healthier meat/fat based diet...one day perhaps!!

PeterVermont said...

I find this study difficult to interpret because the low carb group also had increased protein (20->30%).

The excess energy expenditure may have been due to the increased protein.

Barry Groves said...

Anonymous

Unfortunately , I have no idea what foreign teams are fed. But, as you say, I also suspect they are carb junkies -- although, that said, they don't seem to express the same symptoms of hypoglycaemia that British teams do. It is possible that there may be a difference. I will have to see if I can find out.

Peter
Your point is a valid one, if only because proteins take more energy to digest -- approximately 1 kcal per gram. But that is allowed for when calculating calorie intake. Proteins burned in a bomb calorimeter (which is how calorie values are measured) produce 5.25 kcals per gram. We then knock off one calorie (kcal) to allow for the extra energy used, and then also round down the resultant 4.25 to 4.

As such, any extra energy used as a consequence of the 10% increase in protein intake, surely has already been accounted for.

Barry

PreviLEAN said...
This comment has been removed by a blog administrator.
Alice said...

Dear Barry,

I've just sent you an email using one of your contact forms, then found this page. I'd be really interested in your opinion about what athletes should eat, because I know in Trick and Treat you do not recommend exercise particularly. My husband is a very keen cyclist, for fun not for weight loss, and he thinks that athletes need additional carbohydrates during the activity because the body can't process fat/proteins fast enough to produce energy... could you comment? I'm a bit stumped about what to give him to snack on while he is on the bike.

Secondly, my mum (aged 62) said that medical people always seem surprised to hear that she is not on any medication (not that she goes to the doctor very often). Isn't it really sad?!

Best wishes,

Alice

Anonymous said...

Barry, as a fellow supporter I wonder if you would allow me to post this link for other supporters to sign in the fight for fluoride free tap water.


http://www.change.org/petitions/your-water-is-poisonous

Diana said...

I firmly believe that everyone should have the freedom of choice where their health and fitness are concerned.

If someone wants to play games/run marathons/participate in other exercise, then they must do just that.

I have worked for the last twenty years (as a nurse) with people who have injured themselves through their pursuits. It is sad - so many are left incapacitated and even more run out of steam as they age and become ill (Sir Steve Redgrave became diabetic after many years of carb loading) or they just age very quickly.

My main concern is that whilst I endorse freedom of choice, all these sports people are doing it in the "safe" notion that they are helping their health. The foundations for their choices are based on science which at best is disingenuous and at worst, lies.

Did you see the women's 10,000 meters race in the Olympics? These young women are skeletal and look many years older than their ages. Their bodies may be fit but to be sure, they are not healthy.

Barry Groves said...

I couldn't agree more, Diana.

I'm sure that all these events could be banned under 'health & safety' regulations.

That said, I am not against people doing that they like, so long as it doesn't impact adversely on any other person, and that they take responsibility for any expenses their activities incur.

But I also think that they should be given FACTS on which to base their decisions, rather than the terrible dietary advice they do get - diabetes because of carbo-loading as you say.

No, I didn't watch the 10,000 metres - or any other Olympic event. I am (used to be) a sportsman and have many national and world medals and records to show for it. The Olympics is nothing more than a very expensive TV 'spectacular', and a heavily subsidised advertising medium for junk food companies. I have no interest in supporting this charade.

World Championships on the other hand are another matter entirely. That's where the true sports men and women compete.

Incidentally, can anyone tell me why professionals are allowed to compete against amateurs in all Olympic events except for boxing? Why are professional boxers discriminated against?

Nightingale said...

Perhaps the loss of energy is also due to the spike in blood sugar raising insulin, and when insulin is high, glucagon is low. With glucagon low, the body cannot access its fat stores for energy. I wonder if the Italians are adding olive oil (fat) to their carbs, getting an advantage over the English team.

Just read this article out of the UK: http://www.foxnews.com/health/2012/08/16/study-eating-egg-yolks-almost-as-dangerous-as-smoking/

Oh, brother!

Barry Groves said...

Hi Nightingale

I get the impression that 'scientists' have run out of sensible things to say, so they are making it up.

I mean, for how many centuries - or should that be millennia - have we been eating eggs, with no sign of them causing any disease? So why should eggs be bad for us now?

Or could it be that we have so ruined the food that we eat by changing captive hens' diets?

Strengthens the case for going organic, though.

Barry

Drs. Cynthia and David said...

Tim Noakes, the famous S. African sports physician and researcher, created quite a controversy this year when he came out against high carb diets for athletes. He said that many athletes are in fact carb intolerant and cannot carb load by eating high carb. The interview on Jimmy Moore's site was fascinating. His opinion now is that athletes eating high carb diets are just giving themselves metabolic syndrome despite their large amounts of exercise. He counsels people to tear out the pages on nutrition from his tome "The Lore of Running" until he comes out with a revised addition.

Barry Groves said...

Cynthia & David

Thanks for letting me know that. It's good to see that others are at last catching on to the carbo-loading fallacy

Anonymous said...

Dear Barry,

I think it's better to look at IO 2012 results. As we can see ahtletes all over the world are breaking new olympic and world records in many endurance disciplines during last 10 years
http://en.wikipedia.org/wiki/List_of_Olympic_records_in_athletics

What's interesting less and less records belong to western athletes. But overall there are still new WR and OR. So training methods must be improving worldwide overall. Does this improvement include also diet of athletes? Hard to tell.

leena brash said...
This comment has been removed by a blog administrator.
Anonymous said...

Be interesting to know how Usain Bolt eats....

Anonymous said...

Hi Barry.

Thanks for the article above.

I know some recommend a low carb/high fat diet for endurance athletes as they can use the fat to provide energy instead of carbs.

However I have not seen anyone recommending low carb/high fat diet for high intensity interval sports such as basketball. In fact I have read some advice from supporters of low carb/high fat diets for most people should not be used for athletes in these types of sports because of the need for high stores of glucose in the muscles. There doesn't seem to be much research for low carb/high fat diets for people that participate in these high intensity sports. What is your opinion on this?

I used to follow a high carb/low fat diet until recently when I have changed to a moderate carb and moderate fat diet as I still believe I need some carbs.

Anonymous said...

Carbs are not bad for athletes, how about bananas, apples and oranges for half-time energy.

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