He ate carbs in the form of fruits and vegetables, said Helerstein, and not all carbs are created equal. "[T]he difference is that today the carbohydrates, because they're processed by the food manufacturers, are very high in sugar. And the scientists have a name for that: high gylcemic index -- it just means that it has a lot of sugar in it. So there's a difference between a Milky Way bar and a lettuce leaf, but they are both carbohydrates. So if you are eating the right carbohydrates, the ones that come from the natural sources, the fruits and the vegetables, then you will have a healthy diet."
Helerstein is the chief nutritionist for Diet Chefs, a multimillion dollar company that delivers prepared meals to customers' homes, meals based on the company's 40-30-30 formula: 40 percent low-glycemic "good" carbohydrates, 30 percent lean protein and 30 percent "good" fat. Standing at a table filled with Diet Chefs meals, Helerstein points to a typical Diet Chefs dinner.
"This would be a typical, wonderful meal that any scientist would be happy to eat," Helerstein said. "You have got your basic protein in your chicken. Now that's a lean protein chicken. Your carbohydrates are coming to you from the natural carbohydrates, which in this particular case is salad and vegetables, and then in your dressing here there's a little bit of olive oil and some flavoring that you're able to pour over your salad and you have each of the protein, the carbohydrate and the fat. That keeps your insulin levels stable and that's what health is all about."
Helerstein and Taubes agree that the low-fat proponents got it wrong. Fat supplies much of the taste in food, which leads to satiety, the feeling of being full. In a way, eating fat helps us know we've had enough and it's time to get up from the table. Surprisingly, Helerstein and Taubes agree on another theory: that bad carbs can kill. Taubes contends that carbs cause heart disease, cancer, even Alzheimer's disease. "These diseases cluster together in populations," Taubes said. If you get fat you increase your risk of all these diseases. The obese have a higher risk of Alzheimer's than do the lean. So the natural, simplest possible hypothesis is that what causes one causes all."
Helerstein goes further: "If you are eating sugar, and lots and lots of sugar and pasta and bread and white rice and white grains and white bread and white cereal, then you are initiating, after you eat, an insulin response," she said. "Insulin is an inflammatory hormone and it is a storage hormone. And I don't disagree with him. Where I disagree is, what carbohydrates are you eating? If you're eating the low-sugared, natural carbohydrates, they do not contribute to any degenerative diseases. If you are eating the wrong carbohydrates, I agree with him 100 percent."
Taubes' most controversial theories in the book are these: that there's no evidence saturated fat and cholesterol do anything for us, either positive or negative. They don't cause heart disease, he claims. Nor does salt cause high blood pressure and hypertension. He says fiber is not a necessary part of our diet, especially if we cut out the carbs. And perhaps most controversial of all, Taubes said exercise does not lead to weight loss.