You’ve probably read our position before that there are no “good” and “bad” foods—a point backed up by the American Dietetic Association, which represents 70,000 nutrition professionals. Americans received a reminder this week with the news of Mark Haub, a professor at Kansas State University who went on a “junk food” diet for one month. Haub maintained a daily intake of 1,800 calories while eating mostly snack foods and sweets. He lost 18 pounds and even extended his diet for a second month, losing a total of 27 pounds. Today the Boston Herald ran our take on Haub’s diet, in which we reminded readers that all calories are the same when it comes to gaining (or losing) weight, regardless of the source:

You may remember Morgan Spurlock, who tried a different diet for his documentary “Supersize Me.” Spurlock ate McDonald’s at every meal for a month. He gained 24.5 pounds, his cholesterol exploded and he suffered heart palpitations. But unlike Haub, Spurlock refused to exercise. He also consumed more than 5,000 calories daily.

Obviously, neither Haub’s nor Spurlock’s diet is advisable, let alone healthy. But in their extremes, they both prove the same point: Taking responsibility by watching what you eat and exercising is the best way to keep your weight down.

But responsibility is anathema to the cadre of public health busybodies, like the Center for Science in the Public Interest, which has convinced legislators that food, not lack of self control or exercise, is responsible for obesity. San Francisco just banned Happy Meal toys. New York City Mayor Michael Bloomberg wants to force food stamp recipients to give up soda.

But no matter what food they’re in, calories are just energy. Weight gain or loss is due to an imbalance between calories in and calories out. And more and more evidence is pointing to increasingly sedentary lifestyles as a big, fat reason our waistlines have expanded.

Click here to read the full op-ed.