No, there is certainly bad food.

Trans fats are toxic. Too much sugar raises blood glucose, demanding insulin and--over time--wreaking metabolic havoc in the form of diabetes.

Here are other "foods" that are unhealthy: pop tarts, cotton candy, deep fried snickers bars, donuts.

Don't eat them every day? OK, how about once a year? But what about once a week?

Let's get real: most Americans eat the equivalent of the short list above nearly every day. Because "bad foods" are obvious villains but hidden sugar and processed flour are everywhere.

Those ingredients (white flour, sugar, trans fats) are in nearly all food from vending machines, many foods from fast food restaurants, many if not most convenience store foods, and a big portion of sit-down restaurant meals.

The calorie model is, at best, incomplete. Cutting and monitoring calories does not work if you are eating high carb becasue you are continually ratcheting up insulin. Over time, this leads to not only overeating but metabolic derangement. Our habitual diets, unless we are eating at home, are very high carb.

I agree that "one cheat meal a week" is fine--the problem is there are so many bad foods (i.e. foods high in sugar, trans fats, and white flour) that cheating is a daily habit.