With our kitchen cabinets full of sugary snacks, our lunches packed with frozen meals and our dinners tables laden with fast food bags, why are we so shocked that the number of overweight and obese men and women has risen to an estimated 1 billion worldwide? In this country alone, more than 30 percent of the population is overweight, and another 30 percent is obese.

With television, magazines and the Internet flooded with diets, weight loss programs and prescription medications, the steady increase in the percentage of men and women battling weight gain is not only alarming, but can also be confusing.

“The proportion of people at the high end of the weight scale continues to increase at a brisk rate despite increased public attention on the risks of obesity,” said Roland Sturm, an economist at Rand Corporation, a nonprofit research institute.