Mediterranean and Low Carb Diets Shine in Study

A couple of points.

(1) It's interesting that the Mediterranean diet showed the least amount of weight regain when compared to the other two.

http://content.nejm.org/cgi/content/full/359/3/229/F2

That suggests that the Med diet may potentially be better for long term consequences.

(2) Since the study was limited to two years, it doesn't tell us much about the long terms consequences for each diet. One of the big issues for those concerned about diet is long-term weight maintenance, not simply short term weight loss.

I agree that having a dietitian on site can skew the adherence statistics. I think we would all be more likely to maintain a diet or eating change if we had a professional constantly helping us. I think this doesn't truly show how likely someone is to adhere to any of those diets.

I wonder about the idea of low fat diets-- do they get adequate amounts of the good fats?

I don't go low carb or low fat... I go restricted Calorie and as nutrient dense as possible!

Low-fat diets are fundamentally flawed in concept. We have good research records on literally thousands of native and pre-industrial cultures who maintained levels of health vastly better than modern western man. None of these societies, absolutely none, restricted fat consumption. In fact, the majority of them sought out as much dietary fat as they could obtain.

Gary Taubes' "Good Calories, Bad Calories" is a bit of a boring slog to read. But it shows in great detail how the whole low-fat mantra was enshrined by the Government and the medical establishment with virtually no strong supporting evidence.

It seems to me that most modern diet research indicates that we should eat as much pre-industrial food as possible. In other words if your great-great-great-grandmother wouldn't recognize something as good food then don't eat it.

Diet studies are extremely hard to do because of the huge number of variables. All sorts of things can skew the results. The most significant aspect of this study’s results is the difference between the men’s and women’s loss in all three diets. No definite conclusions can be drawn from it as gender differences was not the focus, but it hints at the greater picture.

Of note is that calories were unrestricted only on the low carb diet. Eat all you want, and not worry about insulin.

It is insulin, after all, that causes fat gain or retention. This points out the lack of success in the low fat group, metered only by caloric restriction, in its efforts to induce weight loss. It is the inferior route.

I'm impressed that the Atkins group was able to lose weight and keep it off without conscious caloric restriction. I guess there's just so much bacon you can stand. The Atkins group, like the other two groups, did unconsciously restrict their caloric intake. All three groups cut calories by about 450 per day, compared with baseline intake. I believe the Mediterranean diet does have documented health benefits: prolonged life, less cancer, less dementia, less cardiovascular disease. But weight loss with a Mediterranean diet does require conscious caloric restriction. I have to agree with the study authors that the Atkins diet may be one of the best for people who need to lose weight, but who refuse to consciously restrict caloric intake.

BTW, the Atkins group had the highest drop-out rate.

-Steve

I find it quite intersting that men lost double the amount on low carb than women did and lost 7x more on the low fat ... makes you wonder:

It's been amusing to see the various interpretations of this study in the headlines:

"Atkins, Low Fat, Low Carb weight loss choices remain blurred"

"low carb better than low fat for weight loss"

"low carb diet effective at helping weight loss for a short term"

"healthy diets have advantages despite insignificant weight loss".

"unrestricted low carb diet wins hands down"

It's funny to see how the study is being spun. It's also interesting to see news outlets relegate the study to a low carb vs. low fat issue.

The Atkins diet is not an all-you-can-eat bacon diet. I just thought I'd put that out there since everything I hear from people who haven't read the book is "The Atkins diet is just butter and bacon, it's so unhealthy."
It frustrates me that they "modified" the low carb diet as they did. I am fairly certain that if they had had the participants do by-the-book Atkins, there would have been far greater weight loss and improved lipid profiles.

To address some issues brought up above...

The researchers based the low-carb diet explicitly on Atkins New Diet Revolution of 2002. In their study, saturated fat was "not specifically restricted, but moderation recommended." For the Atkins cohort, "The intakes of total calories, protein, and fat were not limited. However, the participants were counseled to choose vegetarian sources of fat and protein and to avoid trans fats."

I don't recall if Dr. Robert C. Atkins recommended "vegetarian sources of fat and protein," nor how much. Vegetarian fats must be vegetable oils and nuts. To an Atkins aficionado, what would be so special about vegetarian proteins?

The research was "supported by" (funded by?) the Nuclear Research Center Negev, the S. Daniel Abraham International Cneter for Health and Nutrition, and the Atkins Research Foundation.

-Steve

I think this link presents the study in a fair, unbiased manner.

http://www.nytimes.com/2008/07/17/health/nutrition/17diets.html?partner=rssnyt&emc=rss

I feel the bottom line is the participants did poorly on all of them. The "diet" is not the weak link :-(

Diet research is hard to do, and this study benefited from having a relatively controlled setting (workplace with main meal being served there). This is also a weakness, because few in the real world have that much structure and support. Take home for me is that even with almost ideal conditions it is hard to lose much weight, but weight can be maintained after the initial six months and the health benefits continue in the maintenance phase. Also, the study does help us (a little) choose what kinds of foods we may add or subtract from our permanent diet (lifestyle), as opposed to a temporary weight loss diet. So, for example, I may decide to add more fish and chicken (and less red meat), more Tabouli (I love it), and less sugar and starch (if I cut way down on these, I won't have to count Calories so much). Nothing we didn't already kind of know, but this is reinforcement for that. The gender differences are intriguing, but probably not that significant since only 16% of the subjects were women.

You forgot to mention that they only lost weight for 6 months -- the rest of the time was spent regaining.

Many of the men dropped out also -- and they just used their last weight as an end weight, making it appear as though they'd maintained.

Susan, the study authors don't provided the drop-out rate specifically for men (unless I missed it during my three reads). The drop-out rates were: 10% for low-fat, 15% for Mediterranean, and 22% for low-carb. These rates are a strength of the study, not a weakness.

So most people hung around for the 24-month study. You could indeed argue that many of them were not actually fully compliant with diet guidelines for 24 months. I expect that is the case in reality.

Note that the low-carb dieters were not following the program they were given. At 24 months, the low-carb dieters were getting 40% of their daily calories as carbohydrates. The other two groups were eating 50% of energy intake from carbs. This still seems like a lot of carbs to eat on the Atkins diet. A gram of carbs has 4 calories. The stated carbohydrate goal for the low-carb group was a maximum of 120 grams of carbs daily, on a diet of 1800 calories. So 120 grams of carbohydrate should be 27% of total daily calories, not 40%. At no point did the low-carb group reduce their average percentage of calories from carbohydrates under 40%. OK, maybe be in the first two weeks but those data are not reported. On an 1800 calorie diet, 40% of calories from carbs would be 180 grams. [I'm sure someone will correct me if my math is wrong!]

So the low-carb group may well have achieved greater weight loss if they had been more compliant. But you could say the same about the low-fat and Mediterranean cohorts.

-Steve

The main thing I noticed from this study was that the average weight loss was around 10 lbs, in 2 YEARS! I acknowledge that there were some health benefits, but from a fat loss perspective these results are very poor.

Healthy fat loss doesn't have to take this long at all. In fact, you can lose 5-10 lbs in 1-2 months and enjoy many of the same health benefits obtained above.

Of course, the media is always looking for the next best thing. In reality, we all know that there are many different ways to lose fat and promote health at the same time.

The other thing about this study was that I think it's highly unreplicable... not only because you're unlikely to find your workplace changing the entire cafetaria, having dieticians on site and even going as far as labelling food - but one of the interesting features of this study was the high amount of spousal support to continue with the diet options after hours. Well 86% of the participants were men. I can't help wondering if 86% of the study were women if they would have received the same kind of spousal support given that (in general) women are conditioned to be the caregivers and food prepareres.

John, I think the weight loss was so low because they lost and then regained. Yes, you could lose 10 pounds in two months -- but would be still be 10 lbs lighter when the study ended?

All three groups lost all their weight, on average, during the first six months, then started a gradual return towards baseline weight. The low-carb group lost more than the others during the first six months - 14.3 lb. The Mediterraneans re-gained the least - looks like about a pound from the graph in their report. I hadn't noticed it before, but this minimal re-gain for the Mediterranean cohort is intriguing.

As many have pointed out, these are pretty small numbers overall. Average body mass index at the outset was 31. That's a 5-ft, 10-inch person weighing 216 lb.

-Steve

I’m wondering what other people think. I’ve been doing some research on healthy eating and low carb diets in particular and came up with this one site called OpposingViews.com where there are debates by experts on various subjects.

There is one debate called: “Are Low Carb Diets Healthy?”. I like the idea that these people are experts in their fields, but this one guy says something that gives me pause. He says something to the effect that eating whole plant foods is associated with having good health but diets high in animal protein and fats are not. He also says that in a global sense, a sustained low carbohydrate diet which comes mainly from animal foods creates significant challenges for the planet and also other health issues for people such as antibiotic resistance.”

What do you think he means when he says that a diet which comes primarily from animal proteins is bad for the planet? That’s the first time I ever heard that. If you have time, take a look and let me know what you think by posting your comment. Thanks! http://www.opposingviews.com/questions/are-low-carb-diets-healthy