New Data Validate the Low-Glycemic Diet
 

New data validate the low-glycemic diet

Recruits sought for large human trial of 'Atkins alternative'

A carefully controlled animal study provides clear evidence that a low-glycemic-index (low-GI) diet -- one whose carbohydrates are low in sugar or release sugar slowly -- can lead to weight loss, reduced body fat, and reduction in risk factors for diabetes and cardiovascular disease.

''The study findings should give impetus to large-scale trials of low-GI diets in humans,'' says senior author David Ludwig, MD, PhD, director of the Optimal Weight for Life (OWL) obesity program at Children's Hospital Boston. His group's findings appear in the August 28th issue of The Lancet.

Many studies, including small studies in humans, have suggested that low-GI diets are beneficial, but due to study design, the observed benefits could have come from other aspects of the subjects' diets, such as fiber or overall caloric intake. For this reason, no major health agency or professional association references glycemic index in their dietary guidelines, Ludwig says.

In the current study, rats were fed tightly controlled diets with identical nutrients, except for the type of starch. Both diets were 69 percent carbohydrates, but 11 rats were randomly assigned to a high-GI starch and 10 to a low-GI starch. Food portions were controlled to maintain the same average body weight in the two groups.

At follow-up, the high-GI group had 71 percent more body fat and 8 percent less lean body mass than the low-GI group, despite very similar body weights. The fat in the high-GI group was concentrated in the trunk area, conferring ''the apple shape as opposed to the pear shape,'' Ludwig says. (Having an apple shape is a known risk factor for cardiovascular disease in humans.)

The high-GI group also had significantly greater increases in blood glucose and insulin levels on an oral glucose tolerance test, and far more abnormalities in the pancreatic islet cells that make insulin, all changes that occur in diabetes. Finally, the high-GI group had blood triglyceride levels nearly three times that of the low-GI group, a risk factor for cardiovascular disease.

In a further experiment, rats were randomly assigned to one of the two diets, and, at week 7, were crossed over to the alternate diet for another 3 weeks. Rats that switched from a low to high GI diet showed greater increases in blood glucose and insulin than rats that were switched from high to low GI. Finally, 24 mice were randomly assigned to the low- or hi-GI diet. At week 9, the high-GI group had 93 percent more body fat than mice on the low-GI diet.

''What the study shows is that glycemic index is an independent factor that can have dramatic effects on the major chronic diseases plaguing developed nations -- obesity, diabetes, and heart disease,'' says Ludwig. ''This is the first study with hard endpoints that can definitively identify glycemic index as the active dietary factor.''

Unlike the popular Atkins diet, which seeks to minimize carbohydrate intake, the low-GI diet makes distinctions among carbs. It avoids high glycemic-index foods, such as white bread, refined breakfast cereals, and concentrated sugars, which are rapidly digested and raise blood glucose and insulin to high levels. Instead, it emphasizes carbohydrates that release sugar more slowly, including whole grains, most fruits, vegetables, nuts, and legumes.

''The Atkins diet tries to get rid of all carbohydrates, which we think is excessively restrictive,'' says Ludwig. ''You don't have to go to this extreme if you pay attention to the glycemic index and choose low-GI carbs.''

http://www.scienceblog.com/community/article3840.html

I think it would be safe to call the maintenance phase of Atkins a low-GI diet. Yet another uninformed physician spouting nonsense about Atkins, particularly the last paragraph...

I think they are freaked about Atkins because of the fat. Fat phobia messing up their heads...

And if I eat a bunch of low-GI carbs, I would still be messed up. Give me my fat & protien, please.

The quote is the usual misinformed drivel perpuating misconceptions about Atkins.

However I agree with low-glycemic diets....they work. That's how I lost my weight initially. I suspect it will work for anyone that doesn't have addiction issues, or that is otherwise messed up with regards to carbs.

Anything that turns people away from pre-packaged, highly processed, refined junk is a step in the right direction.

Still, they should stop being so freaking hysterical about low-carb. They fail to acknowlege the wide-spread existence of grain intolerance. In any case, some people do better with severely restricted carbs. Without an induction period such as Atkins, how is anyone ever going to realize this unless they try it.

I wish there was less hysterical arm waving and more logic when it comes to nutrition

''The Atkins diet tries to get rid of all carbohydrates, which we think is excessively restrictive,'' says Ludwig. ''You don't have to go to this extreme if you pay attention to the glycemic index and choose low-GI carbs.''


I really wish these people would get a clue.

"Food portions were controlled to maintain the same average body weight in the two groups. "

This was then a controlled calories experiment also. It says nothing about what would have happened if the animals were allowed to eat all that they wanted of the low-GI carbs.

Again, good news for rats.

Funny how much money we spend trying to find out what happens when rats eat different things.

This also smacks of people designing a study to get the results they want. They WANT the low-glycemic diet to be right. They want OTHER people to believe it, too, so they design a study to show it's good. People don't design experiments to learn things any more. . . they design them to prove a point, which has already been pre-decided.



Me, I'll stick with the lowest-GI diet there is. Meat and green veggies.

Doubts over good carb diet claims

Nutritionists have cast doubt on a Lancet study showing cutting out "bad" carbohydrates leads to weight-loss.
They were commenting on US research in the Lancet which showed the diet, which promotes foods with a low glycaemic index (GI) score - could be beneficial.

Foods with low GI scores keep blood sugars stable, eliminating the peaks and troughs which can lead to snacking.

But experts from the British Dietetic Association said cutting calories was still the key to weight-loss.


Eating fewer calories than you need is what will lead to weight loss
Ursula Arens, British Dietetic Association

The US team, which carried its research out on rats, is now planning an 18 month study on humans.
They said the diet, dubbed the "Atkins alternative" led to weight loss, reduced body fat, and reduced risk factors for diabetes and heart disease in the animals.

People on the traditional Atkins diet are advised to minimise their consumption of all kinds of carbohydrates.

But the low GI diet allows people to eat foods such as vegetables, fruits and wholegrain breads which are low in sugar, or which release sugar slowly.

High GI foods, such as white bread, potatoes and refined breakfast cereals, are rapidly digested, creating a surge in blood sugars.

There have been indications that low GI diets can be beneficial, but it has not been clear if this was due to other aspects of diet, such as fibre or overall calorie intake.

Controlled portions

The US researchers fed two groups of rats which were given diets made up of 69% carbohydrates.

However, one group of 11 rats was given high GI carbohydrates and 10 were given low GI carbohydrates.

The rats' meals were strictly controlled to ensure both groups maintained the same average body weight.

Researchers examined the animals after 18 weeks.

They found the high GI group had 71% more body fat and 8% less lean body mass than the low GI group.

In addition, the high GI group had fat concentrated in the middle of their bodies. In humans, this produces the "apple" shape that is a known risk factor for heart disease.

They also had higher levels of triglyceride blood fats, another heart disease risk factor in humans.

The rats also showed the sort of changes linked in humans to a high-risk of diabetes.

In a further experiment, 24 mice were randomly assigned a low or high GI diet.

After nine weeks, the high GI group had 93% more body fat than mice on the low GI diet.

Ice cream

Dr David Ludwig, who led the team at the Children's Hospital in Boston, said: "The study findings should give impetus to large-scale trials of low GI diets in humans.

"What the study shows is that glycaemic index is an independent factor that can have dramatic effects on the major chronic diseases plaguing developed nations - obesity, diabetes and heart disease.

"This is the first study with hard endpoints that can definitively identify glycaemic index as the active dietary factor."

He added: "The Atkins diet tries to get rid of all carbohydrates, which we think is excessively restrictive.

"You don't have to go to this extreme if you pay attention to the glycaemic index and choose low GI carbs."

However, a spokesperson for the Atkins Foundation, said it was "a myth" that the diet tried to eradicate carbohydrates.

"Atkins is about restricting refined carbohydrates such as sugar and white flour, while encouraging the consumption of high quality carbs."

Ursula Arens, a nutritionist and spokeswoman for the British Dietetic Association, told BBC News Online she was unconvinced the findings in rats could be converted to humans.

She added that looking at GI scores should not be the only consideration in a diet.

"If you stuck to foods which had a low GI score, you would be able to eat lots of ice cream - which are low GI foods, but not bananas or rice - which are high.

"And there are many, many people in China and Japan who eat lots of rice every day and are not overweight."

Ms Arens added: "Glycaemic index may play a small part, but there's no getting past the basic fact that eating fewer calories than you need is what will lead to weight loss."

Her views were backed by Dr Toni Steer , a nutritionist with the Medical Research Council who said, although the study was interesting, the issue of how GI foods affected health was "more complex in humans than in rats".

http://news.bbc.co.uk/1/hi/health/3604384.stm

Nice that they contacted the Atkins Foundation for their viewpoint.

Well if the Diabetic Associastion is against it, it's got to be good somehow.

But seriously, there is at least one lower-carb plan that is based on eating low-glycemic food (Montignac) and it's been very effective for many people at dropping pounds. Like Atkins, it doesn't control quantities. However it's a bit kooky in part.

However I believe that turning away from refined food will allow the majority of people to drop some weight. That's why a variety of lower-carb plans work and that's where Weight Watcher fails.

I agree. I find it is virtually impossible to binge or overeat when you are eating whole (as it grew) food.

I love steak, but never find myself eating it beyond hunger. Same for broccoli. Even when it's slathered in butter, I can't overeat it. Salmon, calamari, pork roast, same thing. I love it, but rarely overdo. Soon as you put food in a machine, add twenty-seven other ingredients, then grind it to an unrecognizable pulp, then fry it in oil, and coat it with pasteurized process cheese-like substance. . . that's when I'll over eat.

OH! I was totally loving this article UNTIL...

1) Glycemic index alone is insignificant. Glycemic load is all that matters. Glycemic index is but one of two major factors of glycemic load. The second major factor is total amount of carbohydrate consumed.
To calculate glycemic load, multiply the glycemic index of the carb by the total amount consumed, and divide by 100 (the "control" GI - that of white bread).

The low-GI mice did so well only because they were compared to a group which was on a diet which contained the same amount of carbohydrate. The only difference between the groups was the carbohydrate in the other group was far more "potent" in its destructive potential.
What do you think would happen if they not only tested the affects of various types of carbs (differentiated by GI), but also if they tested the affects of various quantities of carbs? As I said, both are significant factors of glycemic load, and the ultimate goal is to keep glycemic load very low.

It's as if you took 2 groups of teenage boys, and you told group 1 to consume a quart of vodka daily, and group 2 to consume a quart of Budweiser daily. Of course the first group is going to be in worse shape than the second group. Does this mean drinking a quart of Budweiser daily is the ideal way to live your life, and a healthy addition to one's diet?
Now, how do you think the results would turn out of group 1 was drinking only 2 tbsp of vodka, but group 2 was still chugging a whole quart? Sure, the vodka is more potent than the Budweiser, but if you are consuming so much more of the later, you WILL be affected more. Odds are group 1 would be way better off than group 2 at the end of such a study.

2) The atkins diet does NOT try to get rid of all carbohydrates. What a ridiculous lie. First of all, people often use the term carbohydrate incorrectly. All carbohydrate is, is sugar of some sort. However people often call whole foods like berries, spinach, and avocado "carbs" simply because these beautiful foods happen to contain carbs. Yes, sucrose (table sugar) is a carb. So is corn syrup. It contains nothing but carbohydrate making it a carb. It has no nutritional value other than the raw sugar energy. No, berries, spinach, and avocado are not carbs. These foods merely contain carbs - as well as many other vital nutrients.

With that said, Atkins does not seek to totally eliminate carbohydrate from the diet, and it definitely does not seek to totally eliminate carbohydrate containing foods either. Atkins teaches people how to eat healthfully. It teaches you the best foods to consume are those that are lowest in carbohydrate (sugar), and highest in nutrients (amino acids, fatty acids, phytochemicals, minerals, vitamins, etc). I don't see how anyone can disagree with this.

3) Perhaps it is true that some people who have very good sugar metabolisms (or certain lifestyles) can afford only to eat low GI, and need not control for total amount of sugar consumed. However, I think this is not the norm. Look at the epidemics of disease we have in this country, rates of obesity, diabetes, CHD, being the most prominent. Anyone with a strong familiar history of these, or a personal history themselves, cannot afford NOT to control total carbohydrate consumption in addition to GI.

No, I don't think Atkins is a low GI diet in any phase. A low GI diet does not seek to alter macronutrient composition, meaning it stays within conventional recommended guidelines for consumption of fat/protein/carb. It only asks people to select for their 65% of carbs things like whole grains instead of refined grains, brown rice over white, fructose over sucrose, etc.

Atkins in maintenance is still definitely carb-restricted, even for someone with very low metabolic resistance. I am in maintenance and I consume only 20% carbs on average (slightly less or above that). Granted my metabolism is not like most peoples, but I think the average maintainer isn't ever going to approach the high levels of carbs that you will consume on the low GI diet.

Ah good point...
This is all nice and good in the lab, but I bet the low GI mice were still pretty hungry :). Probably not as bad as the quasi-diabetic, obese, CHD predisposed high GI group though, poor little guys :(.

This is the problem with these kinds of nutritional experiments. They compare only two options, with the assumption that "the answer" can only be one of those two. The experiments are false, because there are more options, specifically a diet which is low GI as well as controlled carb.

A low-carb diet is almost always going to be low on the glycemic index, because fat and protein, for the most part, aren't glycemic (don't cause rises in blood sugar).

I used to be able to get away with eating more carbs as long as they were lower GI, but, alas, menopause seems to have "fixed" that, and it's low-carb forever for me!

David Ludwig is tied into Harvard University and may be an associate of Walter Willett. I am surprised at how slow this group is at catching on to what Atkins actually said. (OK, I should know better.)