But most of the guys I ride with are like me: in their 40s and 50s with jobs and families, long past racing prime. We ride because it is fun, and it feels good to be fit. So why obsess over a few pounds? Because that is the cycling culture--emblematic of our society at large--and it carries its own internal calculus: the amount of guilt is directly proportional to the rise in the quantity and tastiness of the food.
The problem is that our bodies have evolved to crave copious amounts of rich and tasty foods, because historically such foods were valuable and rare. How can we modern humans resist? We shouldn't, at least not entirely, says Barry Glassner, a University of Southern California sociologist and author of the forthcoming book The Gospel of Food: Everything You Think You Know about Food Is Wrong (Ecco). We have wrongly embraced what Glassner calls "the gospel of naught," the view that "the worth of a meal lies principally in what it lacks. The less sugar, salt, fat, calories, carbs, preservatives, additives, or other suspect stuff, the better the meal." The science behind this culinary religion, Glassner says, is close to naught.
When it comes to healthy absorption of nutrients, taste matters. Glassner cites a study in which "Swedish and Thai women were fed a Thai dish that the Swedes found overly spicy. The Thai women, who liked the dish, absorbed more iron from the meal. When the researchers reversed the experiment and served hamburger, potatoes, and beans, the Swedes, who like this food, absorbed more iron. Most telling was a third variation of the experiment, in which both the Swedes and the Thais were given food that was high in nutrients but consisted of a sticky, savorless paste. In this case, neither group absorbed much iron."
"A diet that is harmful to one person may be consumed with impunity by another."
Speaking of iron, Atkins is out and meat is bad, right? Wrong. Glassner notes a study showing that as meat consumption and blood cholesterol levels increased in groups of Greeks, Italians and Japanese, their death rates from heart disease decreased. Of course, many other variables are involved in determining causal relations between diet and health. Glassner cites a study showing a 28 percent decrease in risk of heart attacks among nonsmokers who exercised 30 minutes a day, consumed fish, fiber and folate; they also avoided saturated fats, trans fats and glucose-spiking carbs. According to Harvard University epidemiologist Karin Michels, "It appears more important to increase the number of healthy foods regularly consumed than to reduce the number of less healthy foods regularly consumed."
It's more complicated still. Glassner reviews research showing that heart disease, cancer and other illnesses are significantly increased by "viral and bacterial infections, job stress, living in distressed neighborhoods, early deficits such as malnutrition, low birth weight, lack of parental support, and chronic sleep loss during adolescence and adulthood." Another study found that such diseases "are higher in states where participation in civic life is low, racial prejudice is high, or a large gap exists between the incomes of the rich and poor and of women and men."
To clarify this cornucopia of data, Glassner quotes the former editor of the New England Journal of Medicine, Marcia Angell: "Although we would all like to believe that changes in diet or lifestyle can greatly improve our health, the likelihood is that, with a few exceptions such as smoking cessation, many if not most such changes will produce only small effects. And the effects may not be consistent. A diet that is harmful to one person may be consumed with impunity by another."