CNN.com Health: Study weighs success of four popular diets

[Kaido]

http://www.cnn.com/2009/HEALTH...5/best.diet/index.html

My favorite line:

"The take-home would be that there is no markedly superior diet. If there was, people wouldn't stick with it anyway."

:laugh:

 

[BeauJangles]

Honestly, what a dumb study.

They reduced people's calories and gave them support groups. Of course that will result in a weight reduction. Jesus, it's like they're trying to reinvent the wheel.

 

[bossman34]

Wow, I wonder how much funding they got for this study. They could have given the money to me and I would have told them exactly the same thing.

 

[KingGheedora]

Originally posted by: BeauJangles
Honestly, what a dumb study.

They reduced people's calories and gave them support groups. Of course that will result in a weight reduction. Jesus, it's like they're trying to reinvent the wheel.

I think they were trying to see which diet may work better than others. For this kind of comparison the calories consumed should be the same across all the different diets being tested, and it sholdn't matter if the people were on restricted calorie diets as long as the restriction amount was the same across the groups.


EDIT: Yeah it's kind of obvious if you eat the same amount of calories you end up with the same weight loss. But the general public doesn't seem to realize this.

 

[StageLeft]

Originally posted by: BeauJangles
Honestly, what a dumb study.

They reduced people's calories and gave them support groups. Of course that will result in a weight reduction. Jesus, it's like they're trying to reinvent the wheel.

But a lot of people still don't get it. Everybody I know who is in good shape (granted, that's like three people) know that calorie restriction is key, the rest is minutiae. The general public is still looking for a way to be lean without ever being hungry though. They might as well be trying to turn lead to gold.

 

[KoolDrew]

But a lot of people still don't get it.

And that's the point. It has been proved time and time again that calories are what it all boils down to, yet most people just don't get it.

 

[CRXican]

boo, I wanted to be the first to post this

I hope whats his face and whats his name that made that super long thread about "what your calories comes from really matters, blah blah blah" see this

 

[BeauJangles]

Originally posted by: CRXican
boo, I wanted to be the first to post this

I hope whats his face and whats his name that made that super long thread about "what your calories comes from really matters, blah blah blah" see this

What you eat can have an impact on your health, but those benefits are often only seem AFTER you're actually healthy and active. I know plenty of people on the paleo-zone diet and I've seen how it positively affects their overall health and fitness.

If you're 85 lbs overweight, though, the key is to get the weight off and keep it off before considering anything more radical.

Originally posted by: KingGheedora

Originally posted by: BeauJangles
Honestly, what a dumb study.

They reduced people's calories and gave them support groups. Of course that will result in a weight reduction. Jesus, it's like they're trying to reinvent the wheel.

I think they were trying to see which diet may work better than others. For this kind of comparison the calories consumed should be the same across all the different diets being tested, and it sholdn't matter if the people were on restricted calorie diets as long as the restriction amount was the same across the groups.


EDIT: Yeah it's kind of obvious if you eat the same amount of calories you end up with the same weight loss. But the general public doesn't seem to realize this.

The biggest problem I have with the study is that they offered the people support groups. I guarantee that you will see better or more consistent weight loss in group settings than you will alone, particularly when those groups involve strangers.

Ultimately, though, this study shows what we already know. First, that calorie reduction is a good thing. Second, that keeping the weight off is exceptionally hard for most people which probably means that these diets DON'T "work." I don't know people can't stick to them, but the long-term failure rate for most diets is unbelievably high. I imagine it has something to do with the cost of better food and the prevalence of crappy food in our society.

 

[brikis98]

As I read through Michael Pollan's In Defense of Food, I'm definitely starting to look at these sorts of studies from a different perspective and I really have to question the conclusions being drawn from them.

First, does anyone else think that an average weight loss of 9lbs after two years is... kind of low? Consider the fact that participants were supposedly on a ~750 daily caloric deficit for two years. Do the math. That should have amounted to ~150lbs of fat loss (3500 calories per pound of fat) after 730 days. And that's not counting the fact that "participants were asked to do 90 minutes of moderate exercise each week" which should have increased the caloric deficit even more. The fact that the weight loss was no where near the amount predicted by "calories in vs. calories out" is an indication that (a) the majority of the participants did not maintain their assigned caloric intake and that (b) "calories in vs. calories out" is not as simple as it sounds. It's also worth noting that "individual counseling was provided every eight weeks over two years and group sessions were held three out of four weeks during the first six months and two out of four weeks from six months to two years." This is a far cry from the kind of support an average American would get while struggling to lose weight, so in the real world, you'd expect the average weight loss to be even less. Given that one third of Americans are obese, it seems to me that 9lbs won't make enough of a difference to make "calorie restriction" the national policy. It's also tough to decide how much of the results were a result of the recommendation that "the diets followed heart-healthy principles, replacing saturated with unsaturated fat and were high in whole cereal grains, fruits and vegetables". If participants not only changed how much they ate, but also what they ate and how much they exercised, then it seems like we have too many variables to conclude that calorie intake is the one that really matters.

Finally, it's also a bit odd that low carb diets were actually left out of the study, even though CNN mentions "low carb" in the article's title. The study defined "low fat" as 20% fat and "high fat" as 40% fat. Since the lowest percentage of carbs in any of the 4 groups was 35% (the other groups had 45%, 55%, and 65%), then at best, we had one "moderate carb" group and a whole bunch of "high carb" groups. Since low carb and ketogenic diets are the primary "fad diets" these days, why on earth would they leave them out of the study?

 

[bossman34]

The biggest problem I have with the study is that they offered the people support groups. I guarantee that you will see better or more consistent weight loss in group settings than you will alone, particularly when those groups involve strangers.

Ultimately, though, this study shows what we already know. First, that calorie reduction is a good thing. Second, that keeping the weight off is exceptionally hard for most people which probably means that these diets DON'T "work." I don't know people can't stick to them, but the long-term failure rate for most diets is unbelievably high. I imagine it has something to do with the cost of better food and the prevalence of crappy food in our society.

I think that the reason most "diets" don't work is because most of them are extreme and don't teach people how to just follow a realistic, well balanced diet. Since diets are extreme people don't stick with them forever and as soon as they stop they go back to their old ways because they didn't truly learn how to eat right.

 

[TallBill]

Originally posted by: bossman34

I think that the reason most "diets" don't work is because most of them are extreme and don't teach people how to just follow a realistic, well balanced diet. Since diets are extreme people don't stick with them forever and as soon as they stop they go back to their old ways because they didn't truly learn how to eat right.

Definitely! My wife's friend went on a 1000 calorie a day diet to lose weight. Not sure how long she stuck with it, but I know a few months later she's right back to where she started.

If only she'd let me help plan things out and show her the gym.

 

[KoolDrew]

(a) the majority of the participants did not maintain their assigned caloric intake

Which is usually the case. Ask any fat person to write down what they ate on a particular day and how many servings. I bet what they think they ate and what they actually ate are going to be very different. It's the same with so called "hard gainers" that claim to eat a ton, when they really don't.

 

[TallBill]

Originally posted by: KoolDrew

(a) the majority of the participants did not maintain their assigned caloric intake

Which is usually the case. Ask any fat person to write down what they ate on a particular day and how many servings. I bet what they think they ate and what they actually ate are going to be very different. It's the same with so called "hard gainers" that claim to eat a ton, when they really don't.

I used to think that I ate a ton, then I got on the 6k a day diet Holding steady at about 4k a day now.

 

[bossman34]

Originally posted by: brikis98
As I read through Michael Pollan's In Defense of Food, I'm definitely starting to look at these sorts of studies from a different perspective and I really have to question the conclusions being drawn from them.

First, does anyone else think that an average weight loss of 9lbs after two years is... kind of low? Consider the fact that participants were supposedly on a ~750 daily caloric deficit for two years. Do the math. That should have amounted to ~150lbs of fat loss (3500 calories per pound of fat) after 730 days. And that's not counting the fact that "participants were asked to do 90 minutes of moderate exercise each week" which should have increased the caloric deficit even more. The fact that the weight loss was no where near the amount predicted by "calories in vs. calories out" is an indication that (a) the majority of the participants did not maintain their assigned caloric intake and that (b) "calories in vs. calories out" is not as simple as it sounds. It's also worth noting that "individual counseling was provided every eight weeks over two years and group sessions were held three out of four weeks during the first six months and two out of four weeks from six months to two years." This is a far cry from the kind of support an average American would get while struggling to lose weight, so in the real world, you'd expect the average weight loss to be even less. Given that one third of Americans are obese, it seems to me that 9lbs won't make enough of a difference to make "calorie restriction" the national policy. It's also tough to decide how much of the results were a result of the recommendation that "the diets followed heart-healthy principles, replacing saturated with unsaturated fat and were high in whole cereal grains, fruits and vegetables". If participants not only changed how much they ate, but also what they ate and how much they exercised, then it seems like we have too many variables to conclude that calorie intake is the one that really matters.

Finally, it's also a bit odd that low carb diets were actually left out of the study, even though CNN mentions "low carb" in the article's title. The study defined "low fat" as 20% fat and "high fat" as 40% fat. Since the lowest percentage of carbs in any of the 4 groups was 35% (the other groups had 45%, 55%, and 65%), then at best, we had one "moderate carb" group and a whole bunch of "high carb" groups. Since low carb and ketogenic diets are the primary "fad diets" these days, why on earth would they leave them out of the study?

Yes, they were "supposedly" on a 750 daily calorie deficit. Just because that is what was prescribed doesn't mean than all participants adhered to that over two years...especially if they were only getting counseling every 8 weeks. Although, it does say that those who had better attendance saw stronger weight loss results. Also, most participants lost 13 pounds in the first 6 months, while not huge, is pretty good. Do you really expect all 800 people to lose even a pound a week consistently? This wouldn't happen with low carb or ketogenic diets either.

The study isn't perfect, but studies of this size never are. It's impossible to get full compliance out of 800+ people over two years.

Sacks recommends going with "the diet you feel most comfortable that is healthy, that appeals to you in terms of what foods are in it, that isn't a drastic crash diet. Whatever allows you to keep the calories down and not feel really deprived."

I think this quote sums it up quite nicely. Crazy fad/crash diets are unnecessary and don't work over the long term.

 

[brikis98]

Originally posted by: bossman34
Yes, they were "supposedly" on a 750 daily calorie deficit. Just because that is what was prescribed doesn't mean than all participants adhered to that over two years...especially if they were only getting counseling every 8 weeks.

If participants in a study who "only" got counseling once every 8 weeks couldn't maintain their caloric deficit, how is the average person supposed to?

Originally posted by: bossman34
Also, most participants lost 13 pounds in the first 6 months, while not huge, is pretty good.

If they were keeping a daily deficit of 750 calories, they should've lost 13 pounds in about 2 months, not 6. No, I'm not knocking 13 pounds of weight loss in 6 months as it's a pretty good result. However, it's worth pointing out that people couldn't stick to their caloric deficit for even that period of time.

Originally posted by: bossman34
Do you really expect all 800 people to lose even a pound a week consistently? This wouldn't happen with low carb or ketogenic diets either.

No, of course not. The goal of a diet shouldn't be to lose weight indefinitely, but to achieve an "ideal" weight for the majority of participants and to maintain that weight afterwords. It was not clear from the study whether this happened or not. All the participants in the study were overweight or obese and I'm not sure 9lbs of weight loss was enough to bring many of the participants down to a normal/healthy bodyweight. I suspect it wasn't. Of course, they did find improvements in other health indicators, such as cholesterol and blood pressure, which is great, but the cause is again unclear. Was it the weight loss? The change in the type of food eaten? The extra exercise?

Oh, and to be clear: I am NOT saying that a low carb or ketogenic diet would've worked better. I only brought them up because both were VERY conspicuously absent from this study.

Originally posted by: bossman34
Sacks recommends going with "the diet you feel most comfortable that is healthy, that appeals to you in terms of what foods are in it, that isn't a drastic crash diet. Whatever allows you to keep the calories down and not feel really deprived."

I think this quote sums it up quite nicely. Crazy fad/crash diets are unnecessary and don't work over the long term.

I certainly agree that "crash" diets that involve some short term change cannot possibly be a long term solution. However, it seems that this study is trying to make the conclusion that the type of food you eat is not important, only the quantity. I do NOT think this is supported by the evidence at all.

* The study introduced several key variables besides caloric intake: they actually asked participants to exercise and change the type of food they ate (ie, low in saturated fat, high in whole grains, high fiber etc). This latter part alone should be enough to shoot down the quantity over quality conclusion! Moreover, since both exercise and the recommended foods are both well known for producing the exact same effects this study is interested in - that is, weight loss and improvements in health measures such as cholesterol - then there is just no way that you can conclusively say that the caloric deficit was the only relevant factor.
* The study omitted some of the most popular/important "fad" diets and macronutrient breakdowns, namely low carb and ketogenic, which further diminishes the conclusion that "calories are all that matters". Despite that, I have no doubt this study will be used as an argument against such diets. Did you notice how CNN's article has "low carb" in the title?
* If anything, the study shows that "just" maintaining a caloric deficit is very difficult. As I've already mentioned, subjects clearly did not maintain the caloric deficits they were supposed to, despite unsually favorable conditions to do so (ie, counseling).
* It's also not clear whether the weight loss produced by whatever caloric deficit they did maintain is enough to really be considered "effective" over a 2 year period.

 

[Syringer]

Their low carb diet isn't really low carb anyway--true "low carb" is getting into ketosis which requires less than 40 carbs a day or ~5% of your caloric intake from carbs..the lowest carb % they have here is 35%.

 

[SagaLore]

Diet 1: 20% fat;15% protein; 65% carbs

Diet 2: 20% fat; 25% protein;55% carbs

Diet 3: 40% fat; 15% protein;45% carbs

Diet 4: 40% fat; 25% protein;35% carbs

That's a lot of fat! :shocked:

 

[bobsmith1492]

Originally posted by: SagaLore

Diet 1: 20% fat;15% protein; 65% carbs

Diet 2: 20% fat; 25% protein;55% carbs

Diet 3: 40% fat; 15% protein;45% carbs

Diet 4: 40% fat; 25% protein;35% carbs

That's a lot of fat! :shocked:

Could be worse; imagine a year eating mostly seal blubber.