If the more easily digestible carbohydrates are indeed addictive, this changes the terms of all discussions about the efficacy of carbohydrate-restricted diets. That someone might find living without starches, flour, and sugar to be difficult, and that there might be physical symptoms accompanying the withdrawal process, does not speak to the possibility that they might be healthier and thinner for the effort. No one would argue that quitting smoking (or any other addictive drug) is not salutary, even though ex-smokers invariably miss their cigarettes, and many will ultimately return to smoking, the addiction eventually getting the better of them. The same may be true for these carbohydrates.

It also makes us question the admonitions that carbohydrate restriction cannot “generally be used safely,” as Theodore Van Itallie wrote in 1979, because it has “potential side effects,” including “weakness, apathy, fatigue, nausea, vomiting, dehydration, postural hypotension, and occasional exacerbation of preexisting gout.” The important clinical question is whether these are short-term effects of carbohydrate withdrawal, or chronic effects that might offset the benefits of weight loss. The same is true for the occasional elevation of cholesterol that will occur with fat loss—a condition known as transient hypercholesterolemia—and that is a consequence of the fact that we store cholesterol along with fat in our fat cells. When fatty acids are mobilized, the cholesterol is released as well, and thus serum levels of cholesterol can spike. The existing evidence suggests that this effect will vanish with successful weight loss, regardless of the saturated-fat content of the diet. Nonetheless, it’s often cited as another reason to avoid carbohydrate-restricted diets and to withdraw a patient immediately from the diet should such a thing be observed, under the mistaken impression that this is a chronic effect of a relatively fat-rich diet.