INTERVIEWER My book came out of an accidental observation, which is that I lost weight when I drank sugar soft drinks. Lost weight, not gained weight. That happened in Paris, and I came back to Berkeley, and I found out it was the sugar. In other words, if I drink unflavored sugar water, I lost weight. Not so obvious, right? But Israel Ramirez, who I mentioned a few minutes ago — his experiments with rats are what led me to this discovery. Because I donâ€™t think most people would have thought it was possible to lose weight by drinking Coke, or whatever. But it has to be unflavored. Anyway, the effect never wore off. I drank sugar water for three years, and my weight went down and stayed down. There was no sign that it was ever going to wear off. So this seems to me to be a big problem with your theory, which is that I drank something which obviously raised my insulin level, sugar water. I didnâ€™t measure it. I lost weight and not only did I lose weight, but I kept the weight off, and I lost it without being hungry; I was less hungry than usual. I mean, youâ€™re right, you know, set points, settling points, who cares. . .
TAUBES Itâ€™s important to think of it as a settling point. Because itâ€™s important to have this concept of dynamic equilibrium. As long as youâ€™re thinking about whatâ€™s happening in the brain, which is what set point implies. My question is, what did the sugar water do to your fat tissue? It should have caused you to accumulate fat, or at least hold on to the fat you had, according to what I know of the underlying regulation of fat tissue. The question is, why did it do what it did?
INTERVIEWER I was less surprised than you are, or than most people are, let’s put it that way, because I was led to this observation by a theory. I had a theory which pre-dated all of this. I was kind of surprised my theory was so helpful, because it hadnâ€™t been that helpful before. But, lo and behold, it really turned out to be helpful and it led me to other ways to keep my weight off, and Iâ€™m still way down from where I was.
TAUBES What I ask when I talk with these people. What I say is: Look at the regulation of fat tissue. The question is, how can you lose weight, or gain it — how can you gain weight without either increasing insulin secretion, or increasing the relative insulin sensitivity of the fat tissue to the muscle tissue. Basically, the way we work, at least if you believe the biology that I describe, is that as we secrete insulin in response to the carbohydrates we consume and the insulin works, among other things, to facilitate the movement of glucose into the cells of your muscles and other lean tissues. But blood sugar is kind of toxic, so your muscle tissue doesnâ€™t want the insulin pushing all this blood sugar in, and it becomes insulin resistant. Your fat tissue now remains insulin-sensitive, because your body doesnâ€™t like to waste fuel. So if you eat a high-carb diet, your lean tissue takes up some of the glucose for fuel, and the rest gets dumped in your fat tissue, and your fat tissue remains insulin-sensitive for a long time — far longer. Because once your fat tissue becomes insulin resistant, then you just become diabetic; you have no place to put the glucose. You just pee it out. Thatâ€™s the last resort, because your body doesnâ€™t want to waste fuel.
The thing that Rosalyn Yalow and Solomon Berson reported forty years ago is that organs respond differently to high levels of insulin, and they get insulin resistant at different periods. One of the things I put into a paragraph in the book is that I can imagine a scenario where fat tissue becomes insulin resistant prior to muscle tissue, and the result would be anorexia or bulimia. The person would eat a meal and would have no place to store the calories temporarily. So they would either lose their appetite and not be interested in eating at all (anorexia), or they might just throw it up afterwards. Because they have no place to temporarily store the calories that arenâ€™t being used immediately. Bulimia would be another option. A third option would just be to get on an exercise bicycle and ride for three hours and burn the calories off — be Lance Armstrong, in effect. So what Iâ€™m trying to figure out is what did the sugar water do, unflavored? And itâ€™s interesting — the idea that itâ€™s unflavored might disconnect some of the sort of Pavlovian responses that youâ€™ve developed.
INTERVIEWER Yeah, I think thatâ€™s what was key. The reason I lost my appetite in Paris was that I was drinking unfamiliar sugar water. I think this is the reason that so many diets work in the beginning: because people eat unfamiliar food. Once the food becomes familiar, the diets donâ€™t work so well.
TAUBES This is the problem with anecdotal evidence. The idea that oil could suppress your appetite I could understand, because, as I said in my lecture, you need alpha glycerol phosphate to fix fatty acids as triglycerides. You get the alpha glycerol phosphate from eating carbohydrates, so if you only ate oil it would be shipped off to the fat tissue as triglycerides, then broken down by lipoprotein lipase into fatty acids, but those fatty acids couldn’t be stored in the fat. So it would raise the fatty acid level in your blood, and your body would switch over to burning fatty acids, and this would effectively suppress hunger. That makes sense. But I can’t see why unflavored sugar water would be any different than say, Coca Cola itself, which is just flavored sugar water, for all intents and purposes.
INTERVIEWER Well, when I talked about it in the beginning, I was using fructose.
TAUBES Well, pure fructose, I can also understand. Friedman and Ramirez did an experiment showing that fructose suppresses hunger apparently because it is metabolized in the liver and they believe that the liver monitors fuel status in the bodyâ€¦
INTERVIEWER This is very interesting: someone who is not dedicated to my being wrong.
TAUBES Iâ€™m open-minded.
INTERVIEWER Your book proved that.
TAUBES The experiments that Freedman and I think Ramirez did to demonstrate that the liver must sense hunger, must sense fuel availability, is they did intravenous infusions of fructose, Fructose is metabolized only in the liver. Itâ€™s not metabolized in the brain. So they infused fructose into the blood stream of rats and it suppressed eating behavior. Thatâ€™s one of many experiments they did that suggested that somehow what we sense as hunger is being communicated by the liver. Itâ€™s always made sense to me. So if you only use fructose, and you donâ€™t get an insulin response to fructose, it would make sense that it suppresses hunger. In my book, I discuss the hypothesis that whatever prompts an insulin response is what causes us to get hungry. So, the fructose, I can understand. Actually, if youâ€™re now eating real sucrose, thatâ€™s where it gets complicated, because with sucrose, youâ€™re going to get an insulin response. Unless the fructose component outweighs the glucose, but then, what is it about the absence of taste? Why would Coke make you fat, and sugar water not?
INTERVIEWER Well, first it was it was that flavorless fructose worked. Then it was flavorless sucrose worked. Then it was flavorless oils work. Then it was flavorless any food worked, in particular flavorless protein.
TAUBES When you talk about flavorless protein, what do you mean? The oils, I understand; the fructose fits with everything I know. The sucrose starts getting tricky. What do you mean by flavorless protein? Give me an example.
INTERVIEWER Oh, for example, eating chicken holding your nose clipped. Itâ€™s flavorless in the sense that you donâ€™t smell it.
TAUBES Thatâ€™s interesting. Remember I told you that Jaques Le Magnen started his career studying olfaction (because he was blind). He was curious why the smell of a particular food can go from being very pleasurable when you’re hungry to being nauseating when you’re full. The example I used in the book was the smell of a cinnamon bun cooking. You can imagine that being unbelievably enticing when youâ€™re hungry, and then nauseating if youâ€™ve already eaten three cinnamon buns. Le Magnen moved from that to asking similar questions about the taste of a food, which he thought was determined by our level of hunger. It’s conceivable that if you don’t taste a food it somehow works to suppress hunger, but I have no idea why.