If you have been gaining weight or find it more and more difficult to maintain your weight, you are not alone. According to current statistics, one third of U.S. adults are obese and two-thirds are considered overweight. Being overweight is now the norm in America, since only about three in 10 people are at a healthy body weight.
This is consistent with other reports that show that the waistlines of Americans are expanding. One study looked at the percentage of adults who had a high waist circumference (over 35 inches for women and over 40 inches for men). Overall, the average American added over one inch to their waist circumference over the past decade. Over half of U.S. adults meet the criteria for abdominal obesity. This is bad news, since excess fat, especially around the waist, greatly increases the risk of type 2 diabetes, hypertension and heart disease.
It wasn’t always this way. As recently as the 1980s the prevalence of obesity was much lower, around 15%. There has been much interest in figuring out why this widespread weight gain has occurred. While there is no single cause, there are a host of factors that contribute to the obesity epidemic.
Among the forces that seem to be working against you are your genetics and our environment, specifically as it relates to eating and activity behaviors. Over the past several decades our “food environment” has changed so that now low-quality, high-calorie food is readily accessible and more nutritious food is harder to find and more expensive. Our “activity environment” has changed, too. For most of us, the physical activity that was common at work and home years ago has been replaced by lots of sitting. While there are genes that influence our eating and activity behaviors, these genes have not changed enough over time to explain the obesity epidemic.
A practical explanation for weight gain, both for individuals and the population as a whole, is that we are eating more and expending less energy through activity. Indeed, even small changes in energy balance can add up to increased weight over time. A new study, however, suggests that there may be other factors that may have contributed to the rise in obesity beyond eating and activity.
Among these factors are exposure to certain chemicals (like BPA) in the environment, the use of prescription drugs that may cause weight gain, and how our current diet has changed the bacteria in our intestines, that we now know regulate our physiology in surprising ways. For example, bisphenol A (BPA), still found in some plastics, food containers and receipts, alters normal hormone activity in a way that may increase fat storage.
There is some good news, though. Eating a healthy diet and being active every day can help you lose weight and maintain a healthy weight. This is true whether your concern is changes in your own eating and activity habits or these other potential causes of weight gain. Indeed, regular exercise may help treat many conditions, like depression, for which prescription medications that may cause weight gain are often used. And a diet rich in fruits, vegetables and whole grains and low in added sugar could help restore more normal gut bacteria which may help with weight control. Until we know otherwise, eating smart and moving more is still your best approach to weight control and good health.