The video below shows Chris Gardner, Ph.D., researcher from Stanford University, giving a presentation about the data he generated when he compared the Atkins diet to the Ornish diet, the Zone diet and the LEARN diet. You all probably remember this study, which he published in JAMA in 2007, showing the low-carb diet brought about greater weight loss and better lab value improvement than the other three diets.
As you watch this long video (and you should watch it; it’s extremely entertaining and filled with a ton of good info), there are a few things you should note.
Before we get to that though, let me fill you in on the LEARN diet.
Most of you, I’m sure, are familiar with the ultra-low-fat Ornish diet and the 30-40-30 protein-carb-fat ratio of the Zone diet, but you may not be aware of the LEARN diet. LEARN stands for Lifestyle, Exercise, Attitudes, Relationships and Nutrition and is the brainchild of Kelly Brownell at Yale. The LEARN diet is a low-calorie regimen that recommends 55-60 percent of calories as carbohydrate and under 10 percent of calories as saturated fat. The LEARN program is big with academics (since it was created by one of their own) and is the diet typically used when a diet program is required as part of a study. In fact, the LEARN manual was developed to bring some consistency to the nutritional regimens followed in research. As a consequence of its widespread use in academia, it has also become the program that pretty much mirrors the national guidelines. Or, to put it another way, the nutritional guidelines set by academics pretty much mirror the LEARN program.
If you look at the carb content of the LEARN program and realize that it is the basis for the national nutritional guidelines, you can LEARN why we have an obesity epidemic. But that’s another subject.
First off, at about 17:10 in the video, Dr. Gardner talks about how Dean Ornish got mad at him for publishing this study. (So did Barry Sears, author of the Zone, but Dr. Gardner didn’t mention him.) Both Ornish and Sears got their noses out of joint after this study and sniffed that the study results didn’t really apply to their programs because clearly the data showed that the subjects assigned to their specific diets really weren’t following the diet as designed. Both missed the point.
As Dr. Gardner plainly says, the study is of specific diet books and how patients lose (or don’t lose) weight following these books. You can’t recruit a million people for a nutritional study in which you hold their hands throughout. But you can write a book that a million or more people read and follow. What Gardner was looking for in this study was how people would do following a diet book advocating a specific program as compared to others on different diet books promoting different diets.
As part of the structure of the study, he randomized subjects to the various diets, then had them come in weekly for eight weeks to visit with a dietitian who went over the book with them. He relates an interesting story at about 26:10 that I’m sure is absolutely true. Many of the people who were randomized to their particular diet were demoralized because they had already done that diet in the past and hadn’t done particularly well on it. After going through the book with the dietitian, these same people realized they hadn’t really read the book very well – if at all – the first time through. Once they really read and understood it, they were fired up and ready to go. Based on may questions MD and I have received about our books, I know this only too well.
Earlier in the video, at about the 17:10 point, Dr. Gardner makes an observation that all of us using low-carb diets know well. He is discussing how reducing carbs makes triglycerides go down and adding fat makes HDL go up. He then says that all these people have come into the clinic he is involved with after having been on Ornish or McDougall only to find their triglycerides have skyrocketed and their HDLs have dropped off the chart. He tells them to replace some of the carbohydrate with good quality “unsaturated fats” (sigh), and their labs revert to normal.
At about the 29:00 mark, Dr Gardner points out that as the data came in and was charted, it became apparent that it was difficult for people to stick with the Ornish or Zone diets, and when these subjects fell short of following their specific program, their macronutrient-consumption data ended up falling right smack into the middle of the LEARN data, or the national nutritional guidelines. Those on the Atkins diet morphed a little (toward a more Protein Power sort of plan, but not quite), but not nearly as much as those on the low-fat diets did. After a year, the data ended up showing a bunch of subjects essentially following the national nutritional guidelines and another, smaller bunch, following a semi-Atkins diet.
As Dr. Gardner points out, in virtually every parameter measured, those following the Atkins book who ended up following a semi-Atkins diet triumphed over those following the other books, all of whom ended up following the national nutritional guidelines. Which, of course, is no surprise to most readers of this blog.
But it was a huge surprise to Dr. Gardner, a 25-year-long vegetarian. He admitted it was a bitter pill to swallow, but the data are what the data are. And he was man enough to admit it. I think this study and Dr. Gardner’s engaging presentation style will start getting some notice from mainstreamers. King Canute couldn’t hold back the tide, and I don’t think the lipophobes will be able to hold back low-carb diets forever. This is a great video to show Doubting Thomases if they will take the time to watch it.
Aside from the finding that the low-carb diet was vastly superior, a lot of other data came to light as a consequence of this study. Some people did great on Ornish or the Zone while others did poorly on Atkins. Why? You would think that since all the subjects were humans, they would all respond the same way, but they didn’t.
This intrigued Dr. Gardner, so he began slicing and dicing the data to see what he could come up with. At about the 40:00 point on the video, he discussed a few papers showing that people who are insulin sensitive actually do better on high-carb diets than they do on low-carb diets, whereas those who are insulin resistant do just the opposite.
I pulled all the papers he discussed and plan on reading them over the next ten days while I’m spending (literally) about 24 hours in an airplane seat. (As part of our Sous Vide Supreme tour, MD and I leave tomorrow for Dallas, then Vancouver, Seattle, San Francisco, Chicago, New York, and Las Vegas, so I’ll have plenty of time to read.) I do find this information fascinating, but I have a few reservations as well. There are very few moderate to significantly overweight people who aren’t insulin resistant to some degree, so I’ll be curious to see how the authors of these papers define insulin resistance.
Based on my own experience with a whole lot of patients, there are a few, but not many, overweight people–usually women, but occasionally men–whose lab reports show normal insulin sensitivity. I treated them with a low-carb diet, and they did well. But I didn’t randomize these apparently insulin-sensitive overweight patients into two groups and put one group on a low-carb diet and the other on a low-fat, high-carb diet, so I can’t really say the ones I treated did better than they would have on a low-fat diet.
What I do know, however, is that those who have been overweight and insulin resistant, and who lose their weight and restore their insulin sensitivity with a low-carb diet, will regain in a heartbeat if they go on a high-carb diet for maintenance. So, it’s hard to reconcile this fact that I know from hands-on experience with the data Dr. Gardner presented.
It could have something to do with the genetics that prevent the development of insulin resistance in the first place. I’ll post on my thought about this paradox after I’ve read the relevant papers and reflected on them.
I had only one real objection to this presentation. At the end, during the Q & A, someone asked a question about ketosis, and Dr. Gardner was clearly in above his head. He did make the distinction between the ketosis one experiences on a low-carb diet and the dangerous ketoacidosis that those with uncontrolled type I diabetes are subject to, but he seemed to be uncertain as to whether low-carb ketosis was harmful over the long run. He did remark that everyone is in ketosis part of the day, but then he kind of tossed it off by saying that the people on the Atkins diet weren’t really following it that closely and so weren’t really in ketosis for that long. I wish had addressed the ketosis situation head on. There is no danger in being in ketosis for extended periods of time. Ketones are normal fuels of respiration and don’t pose any problems over the long haul. In fact, some research has shown that ketones are a preferred fuel of many organs including the heart. (Veech et al)
As I’ll be traveling a lot the next 10 days, and since I don’t know my exact schedule even yet, I can’t promise a lot of regular posting. But I will check the blog often and put up the comments as they come in. If any of you have experience with trying a low-fat diet after losing on a low-carb diet, I would love to hear about it.