Some months ago, I discovered that Stanford University has quite a few class lectures available for free on iTunes. I enjoy listening to books and lectures during my long walks, while driving, while sitting on airplanes, and sometimes even while working on programming projects if I’m not in the middle of a real head-scratcher. (Don’t tell my clients.)
I’ve downloaded and listened to several lectures on subjects that interest me: history, politics, science, economics and, of course, health and nutrition. I had planned to transcribe portions of a couple of nutrition lectures so I could comment on them, but since I don’t like typing all that much, I kind of put that project aside.
Turns out one of the lectures I wanted to write about is also on YouTube, as I found out when I visited Mike Eades’ blog this morning. I enjoyed it on iTunes, but it’s even better when you can see the visuals. So in case you haven’t already seen it, here it is. The speaker is Dr. Chris Gardner, a director of Nutrition Studies and an associate professor of medicine at Stanford:
A few things struck me as I listened to the lecture the first time, and again as I watched it today. One is that all diets are difficult to follow to some extent — just look at the dropout rates for the other studies Gardner mentioned. There’s no getting around that. If your weight is going up and your health is going down, you’re on a bad diet. To turn things around, you have to give up some foods you love.
I miss fettuccine alfredo and sourdough toast, but I’ve found it much easier to stick to a low-carb diet than any of the others I tried. Low-fat diets, by contrast, made me feel lethargic and depressed. I’d start cheating, then eventually give up. (Good thing, in retrospect.)
Along those lines, notice what happened in Gardner’s study with the group assigned to the Ornish diet: on average, they began eating double the amount of fat Ornish recommends almost immediately and eventually moved up to triple what he recommends. Ornish has complained that this wasn’t a fair test of his diet since most subjects didn’t stay within the 10% fat limit. I think it’s more likely they couldn’t stay within the 10% limit … their bodies rebelled.
(Here’s how someone once described the Ornish diet: put food in your mouth. If it tastes good, spit it out.)
To be fair, the Atkins group drifted back towards a higher carbohydrate intake as well. If you do the math, it appears that by the end of a year, most of the women in the Atkins group were consuming something in the neighborhood of 150 carbohydrates per day. They ended up on a restricted carbohydrate diet, but not exactly a low- carbohydrate diet.
But that actually makes their weight loss more impressive. Remember, they weren’t told to count calories, as two other groups were. And yet the Atkins group lost the most weight, even though they ate more carbohydrates than Atkins recommended. And as their carbohydrate intake went up over time, so did their weight — again, they weren’t counting calories. This would seem to confirm what Atkins said all along: carbohydrates make you hungry. You have to find the level of carbohydrate intake that keeps your insulin in check and your appetite stable, then stay there.
I also noticed that the Atkins group had the lowest dropout rate. Once again, I’m not surprised. Yes, you may miss your sugars and starches on a low-carb diet, but at least fat is satiating. I never felt satiated on a low-fat diet, unless I ate huge meals.
What really perked up my ears the first time I heard the lecture was the comparison of the health parameters. The Atkins group showed the most improvement in weight, blood pressure, triglycerides and cholesterol levels. No other diet out-performed Atkins on any health parameter. So much for the notion that a low-carb, high-fat diet will kill you.
Gardner even explains, in response to a question, that low-fat, high-carb diets tend to make triglycerides go up, HDL go down, and produce a higher proportion of small, dense LDL. And remember, we’re hearing this from a guy who’s been a vegetarian for 25 years — not exactly a shill for the meat industry.
I also found it interesting the relative success of one diet versus another seems to depend on the dieter’s level of insulin resistance. Now and then, I hear from people who swear they lost a lot of weight on a low-fat diet and felt fine doing it. I believe them. But I’m guessing those are people who aren’t insulin-resistant. They can eat plenty of carbohydrates and lose weight by restricting fat and calories because they don’t end up with high insulin levels that command their bodies to continue storing fat. Good for them.
The problem is, the rest of us are told that if it works for them, it should work for us, too — assuming we just had the proper discipline. But it doesn’t work for us. We produce too much insulin in response to sugar and starch. We have to give up the carbs, or we’re setting ourselves up to fail. And given the steep rise in metabolic syndrome and type II diabetes, I think most overweight Americans are probably insulin-resistant.
This lecture — recounting a study conducted by a committed vegetarian — confirms what I already knew: the usual dietary advice given to overweight people who are developing metabolic syndrome is a load of bologna. Hats off to Dr. Gardner for reporting his results with no apparent attempt to manipulate them. We could use a few more researchers like him.