Ban on supersize soda: are we putting too much emphasis on soda, not portion size in general?

By Deborah Kotz, Globe Staff

I’ve been a little surprised by all the efforts going into banning supersize sodas and sugary beverages, first in New York City, and now in Cambridge. And I’m even more surprised by the rancor it has raised from consumers who want the freedom to be able to order giant cups of calories at their local restaurants.

It’s not like we always had supersize sodas. Coca-Cola used to advertise its 16-ounce bottle as serving a family of three. That’s the current size of a small soda at McDonald’s. A Big Gulp at 7-Eleven -- which won’t fall under the proposed bans -- contains 30 ounces.

Then again, it’s not like we always had 300-calorie bagels or 500-calorie muffins. Restaurant portions and plate sizes have increased to the point that we now look at portion sizes differently than in the past. A 2006 Rutgers University study measured a 20 percent increase in the amount of corn flakes college students put in their cereal bowls compared with 25 years ago, when Penn State University researchers conducted a similar study on their own students.

I was even amazed when I purchased some new silverware last week in a pattern nearly identical to my old one -- that was missing forks and spoons -- by how much the spoon and fork size had increased. (See the photo above.)

This, I thought, is a chief reason behind the obesity epidemic.

The size of packages, plates, utensils, “may involve or suggest a consumption norm that influences how much individuals will eat or drink,” wrote University of Illinois researcher Brian Wansink in a review paper evaluating how environmental factors influence how much food we consume. Our stomachs, he concluded, can always make room for more.

The mayors of New York City and Cambridge believe bans on supersize soda will go a long way toward fixing the obesity problem. New York City health officials, while supporting the ban, have also pointed out in this New York Times article that it’s hardly enough.

(Interestingly, First Lady Michelle Obama -- who has made obesity prevention her key initiative -- hasn’t taken a position for or against the supersize soda ban.)

Still, I wonder if all the animosity generated against the proposed restrictions will make it less likely that food establishments will step up and voluntarily implement other changes, like smaller portions, smaller plates, and smaller utensils. In singling out soda as the root of all waistline evils, are people getting the message that all they need to do is down-size their Sprite if they want to lose weight?

Certainly avoiding sugary sodas and other high-calorie beverages can help people avoid obesity and maybe lose a few pounds if they were consuming these in large quantities. But that won’t solve the supersize candy bar problem or that fact that few of us make an effort to get physical activity.

What do you think? Will a ban on supersized sodas have an impact on obesity?

Deborah Kotz can be reached at dkotz@globe.com. Follow her on Twitter @debkotz2.