From Michelle Obama’s “Let’s Move” campaign for children to the Centers for Disease Control and Prevention’s report last winter, efforts and warnings abound to keep Americans healthy. The January CDC report stated that more than 35 percent of American men and women were obese in 2009–2010. The latest is New York City Mayor Bloomberg’s endorsement of a ban on large soda cups to help solve the problem.

Nevermind that the CDC relies on Body Mass Index (BMI) to measure obesity, which has important limitations. Athletes or others with more muscle mass may have a higher BMI; remember, muscle weighs more than fat! Also, the report noted that recently the rate of increase in obesity appears to be slowing or even a leveling off. Even if America’s weight problem is still very real, the NYC mayor was perhaps flippant in his statement that a ban on large sodas doesn’t limit freedom of choice. After all, he noted on the Today Show one’s right to drink an enormous soda isn’t exactly something America’s framers envisioned.

Last month, National Public Radio aired an interview with Dr. Brian Wansink, author of Mindless Eating and an expert on eating behavior, whose research has contributed to the development of 100 calorie snack packages among other good ideas to encourage people to make healthier choices. Dr. Wansink believes that the NYC ban could amount to a large and visible failure in the fight against obesity. All it will do is penalize retailers who sell large sodas. Some argue this is of course justified since retailers exploit people’s apparent inability to choose healthier options.

Irrespective of what studies show, including the fact that soda calories are a significant portion of the American diet, that drinking a lot of soda correlates with health problems like diabetes and that soda is cheap and therefore appealing, eating healthy food in healthy portions should be a personal choice. The moment we reject the idea that human beings can avoid a big gulp, then we’ve given the government remarkable power to institute a quick ban or sin tax, essentially shaping our choices at the expense of personal liberty and responsibilities.

When it comes down to it, people must make the choice to limit their snacks to 100 calories (rather than eating five 100 calorie snack packs). Innovation, education and encouragement help free people make good choices. Dr. Wansink has noted that retailers should be engaged to create profitable ways for them to encourage healthy eating. This is a better approach, indeed, than having restaurants face fines for selling sodas that come in containers larger than 16 ounces.