Just in time to guarantee a guilt-free feast on Thanksgiving, Dr. Aaron Carroll’s book The Bad Food Bible: How and Why to Eat Sinfully has arrived at your favorite bookseller. Among the gems that Carroll hurls at the nutrition Nazis are that most fats are not bad for you; unless you already have high blood pressure, the amount of salt in your diet is probably fine; your chances of getting severe Salmonella poisoning from raw eggs are miniscule; and processed meats eaten in moderation will not increase your susceptibility to cancer.
As for his advice to Thanksgiving revelers from a recent interview:
Your health and your eating habits are not established by one day a year. It’s perfectly fine to enjoy yourself and to live! You need to weigh — in all your health decisions — the benefits and the harms. And too often we only focus on the latter. And included in benefits are joy, and quality of life and happiness. There are times when it’s a perfectly rational decision to allow yourself to be happy and to enjoy yourself. I’m not sort of giving a license for people to eat whatever they want, anytime they want. Yes, the Diet Coke, the pie, these are all processed foods. So you should think about how much you’re eating them in relation to everything else. But on the other hand, a piece of pie on Thanksgiving is not going to erase everything else you’ve done the rest of the year.
This is good advice, even without Carroll’s analysis of the lack of evidence for much nutritional advice. Unless you have health issues, choosing Thanksgiving Day to make a stand against poor nutrition is just a form of asceticism.
But Carroll’s book does more than give us all an excuse to indulge on occasion. He provides a careful analysis of the data supporting various nutritional guidelines in easy-to-understand prose. In fact, his book would be a good primer to use in a critical thinking class on statistics. Most of the nutritional guidelines we’re encouraged to follow are not well supported by the underlying studies. The problem isn’t that nutrition scientists are dishonest or careless—the problem is that nutritional science is very hard to do well and very expensive, so must studies are too limited and equivocal to allow definitive conclusions. Yet, the public, regulatory agencies, and the press want definitive conclusions so we end up with advice that outstrips evidence.
According to Carroll, not all nutritional advice is bad. Studies supporting the harmful effects of excessive sugar and refined carbohydrates are persuasive, and if you’re among the minority whose dietary cholesterol effects blood cholesterol then dietary modifications may be appropriate. Obviously, excessive calories and the resulting weight gain are not good; healthy eating requires moderation. But generally speaking trying to regulate health by making particular foods off limits is ineffective and unnecessary.
And surely Carroll is right that an occasional indulgence for reasonably healthy people will have no ill effects.
So this Thanksgiving put away the guilt and put away the turkey and stuffing. And think of that food coma as a well-deserved nap.