Whether we're buying a new car or a bagel and a cup of coffee, it's human nature to want to get the best deal. That's probably why we have a tendency to eat everything that's put in front of us. Twenty years ago, that wasn't necessarily a bad thing--you could probably have cleaned your plate and still had room left over for dessert. But in those two decades, portion sizes--particularly in restaurants, where we want to get our money's worth--have grown by a lot. And, not surprisingly, so have we: Thanks to our aversion to leaving behind even one crumb of food that we spent our hard-earned money on, obesity rates in the United States have gone from about 15 percent in 1996 to more than 30 percent today.
Here are just a few examples of the dramatic change in portion size that's happened during your lifetime:
Clearly, we're getting plenty of food. But that hasn't stopped many parents from insisting that our kids finish everything we put down in front of them (a strategy that used to be lovingly known as "being a member of the Clean Plate Club"). Actually, the Clean Plate Club isn't just for kids. A recent study by researchers at Cornell University found that on average, adults eat 91.7 percent of whatever's on their plate--regardless of the size of the plate. "If you put it on your plate, it's going into your stomach," says Brian Wansink, PhD, one of the study's lead authors. Wansink's study included subjects in seven different countries, and the results were essentially the same everywhere. That, in a nutshell, goes a long way toward explaining our obesity problem.
Telling our kids (and ourselves) that we need to clean our plates so we don't waste food--even if what's on the plate is way more than we truly want to eat--essentially trains us to disregard the natural feeling of fullness that our body produces when we've eaten enough. Continuing to eat after we're full is directly linked with obesity, in both childhood and adulthood.
The solution? Well, it's all about size. A number of studies have found that people will serve themselves (and others) larger portions when they're serving from large platters or packages (of cereal, for example), putting those servings into large bowls or dishes, or eating with large utensils. So if we want people to stop overeating and start learning to recognize when to put down their fork and back away from the table, we need to stop supersizing everything and start using normal-sized dishes and silverware. That will lead to smaller servings, which will, in turn, lead to less consumption.