Ho Hum wrote:
The key is sugar. It isn't carbs in general that are making you gain weight, but an excess of simple carbs (sugar, pizza, beer). I guess you could also be eating too much fat, but that's kind of tough to do unless you're eating fried crap all the time.
Sugar is probably the worst form of carbohydrate by a country mile, and fructose probably the worst sugar, but low-carb diets beat high carb diets re: weight loss even when the carb sources are "healthy."
Excerpt from
http://www.fathead-movie.com/index.php/2011/01/13/why-we-get-fat-interview-with-gary-taubes/Fat Head: Even though there’s some new information in Why We Get Fat, the alternative hypothesis you present is pretty much the same as in Good Calories, Bad Calories: carbohydrates drive up insulin, and elevated insulin drives fat accumulation. Your critics often point to populations who eat a high-carb diet — Asians, Kitavans, etc. — as evidence that you’re wrong, since people in those populations don’t generally become fat or diabetic.
Gary Taubes: Well, sometimes I just want to haul off and smack–
Fat Head: Careful, your wife may read this.
Gary Taubes: Oops. Sorry. As I discuss in GCBC, it’s quite likely that sugar — by which I mean a roughly 50-50 mixture of glucose and fructose — is the trigger that first sets off insulin resistance and then the vicious cycle from eating all carbs that leads to obesity, diabetes, etc. And these populations — Southeast Asians, in particular; I’m not really familiar with the Kitavan story — ate excruciatingly little sugar. This, to me, is a primary piece of evidence arguing that sugar may be the necessary trigger. That would explain why when the Asians come to the U.S., they do start succumbing to these metabolic disorders. They start eating more sugar.
Another possible explanation is that the carbs these populations consumed, until very recently, were low glycemic index carbs — not highly refined rice and wheat. There are many variables that could explain it, which is one of the reasons observational evidence like this is so potentially confusing. You have to do clinical trials — i.e., experiments. It’s the only way to get to the truth.
Fat Head: My reply to people who tell me the Kitavans live on starches and therefore I can too is that I’m not a Kitavan. Do you think heredity plays a role in how well we tolerate carbohydrates? Since most people of European extraction can easily digest milk while 90 percent of Asians are lactose intolerant, it’s clear there were different dietary adaptations in different areas of the world.
Gary Taubes: Yes. Heredity and the length of time that a population has been exposed to the carbohydrates in the diet is an important factor, and I discuss this in GCBC. It’s an idea that Peter Cleave gets a large part of the credit for.
Fat Head: Dr. Robert Lustig insists it’s fructose that makes us insulin resistant, not starchy foods. If he’s right, then it was the Coca-Cola and Captain Crunch that turned me into a fat kid, not the mashed potatoes. But as an adult, I’ve avoided sugar yet found that starches most definitely make me gain weight. So assuming for the sake of argument that Lustig is correct, would you say that once fructose has done the damage, we lose our tolerance for carbohydrates in general? If so, why?
Gary Taubes: That’s exactly the possibility I’m discussing. Once you become insulin resistant, your body responds to carbs by secreting more insulin. So it is quite possible — and laboratory work backs this up — that sugar causes the initial insulin resistance because of the effect of the fructose on the liver. So if we never had sugar, we’d be able to eat the other carbs with relative impunity. But being possible doesn’t mean it’s true. I suspect it is, but I’m not sure exactly how this can be tested.
And I agree with you: the world is full of obese and diabetic people who know enough not to eat sugar, but remain obese and diabetic. I could avoid sugar and go back to eating starches and put on 20 pounds of fat effortlessly. I’ve done it in the past — distant past. So I don’t buy the idea that avoiding sugar is enough to make an obese person lean again. And the people I know who believe that all tend to be somewhat plump despite their beliefs. In fact, I recently heard Dr. Lustig give a talk in San Francisco, and he acknowledged that he still has a weight problem, but doesn’t know what to do about it. Hmmm….
Fat Head: Have you come across any evidence that starches can turn people into fat diabetics without fructose being part of the diet?
Gary Taubes: It’s tricky. Typically consumption of sugar, white flour and starchy vegetables all tend to go hand-in-hand. So it’s hard to tease out this one. I suspect beer could, but I don’t know if even beer drinkers who don’t eat sugar tend to become diabetic or not. What we’d need is a population of white-flour eaters who didn’t eat any sugar at all. If we could find such a thing, naturally, then we’d have some idea.
Fat Head: Dr. William Davis tells his blog readers that wheat seems particularly adept at promoting weight gain. Did you come across anything in your research to support that idea? I know for me, wheat jacks up my blood sugar far beyond what the glycemic index or glycemic load charts would predict.
Gary Taubes: Again, it’s possible since most of us eat wheat as refined flour, and refined flour was historically identified as a dietary evil, linked to obesity, at least. So in a sense we’re talking about the same thing but coming at it from different directions. My problem with singling out wheat is that then you ignore sugar and the other various and sundry foods that can promote weight gain. I certainly hear from enough people telling me how their health problems went away when they gave up wheat and gluten in particular. Although they typically go on to say they also, perhaps a little later in the game, gave up sugar and other refined, easily digestible carbs as well.
Fat Head: In Why We Get Fat, you wrote that some people might have to give up dairy products and nuts to lose weight. Dr. Mike Eades has also mentioned that nuts and cheese seem to inhibit weight loss in some low-carb dieters. What is it about those foods that can stall weight loss? Is it just that they’re so calorically dense, or do they produce a higher insulin response than their low carbohydrate content would suggest?
Gary Taubes: I think the caloric density thing is nonsense. Remember, I’m trying to get every last one of us away from thinking in terms of calories as the variable of interest. What we want to know is whether these foods stimulate insulin secretion, or cause insulin resistance, or have some other effect on the storage of fat in the fat tissue or the oxidation of fatty acids by other tissues in the body. So nuts still have carbs in them, and for some people they might contain too many carbs. Same is true for nut butters.
Dairy products can stimulate insulin secretion beyond what you would expect from the carbohydrate content. I don’t know if this is true of cheese because I’ve never seen data on this, but it is possible. And some cheeses could be better than others — hard cheeses, for instance, may be better than soft cheeses.
Fat Head: You wrote something in Why We Get Fat that I think every frustrated dieter needs to hear: the proper diet will help us become as lean as we can be, but not necessarily as lean as we’d like to be. Once we become fat, is there a limit to how much fat we can lose without starving away our lean tissue? If so, what’s the barrier to mobilizing and burning those last 10 or 20 pounds of excess fat?
Gary Taubes: Simple answer, I don’t know. But it’s obvious that not every woman can have the body of an Angelina Jolie, regardless of how few carbs they eat. And not every man can have the body or the body-fat percentage of, I don’t know, a Matthew McConaughey, one of these actors who’s always taking his shirt off in movies.
That’s for starters. Some of us are wired to have more body fat than others from the get-go. Then I think when we grow up in a carb-rich environment, some degree of chronic damage is done to the way we partition fuel. Maybe our muscle tissue never quite loses its insulin resistance, or our fat tissue remains more insulin sensitive than it would be had we never seen carbs. Maybe our pancreas secretes a little too much insulin.
It’s hard to tell, but the way I describe it is this: if I grew up in a hunter-gatherer environment — and my mother did as well, because there are effects that are passed from mother to child through the uterus — I’d probably weigh around 175 pounds, even as an adult. Had I stopped eating carbs in my late teens, I might naturally weigh about 190 or 200, which was my football weight in high school. The fact that I not only kept eating carbohydrates into my forties but gorged on them during the low-fat, you-can’t-get-fat-if-a-food-doesn’t-have-fat-in-it years of the late 1980s and early 1990s means the best I can do now, even eating virtually no carbs at all, is about 220. And there’s nothing I can do to go lower, short of starving myself. Semi-starving myself doesn’t work. I tried that long ago.