Three-quarters of US adults now overweight or obese: study

Nearly three quarters of U.S. adults are overweight or obese, according to a new study.

The findings have wide-reaching implications for the nation's health and

medical costs as it faces a growing burden of weight-related diseases, The New York Times reported.

The study, published in The Lancet on Thursday, revealed the striking rise of obesity rates across the country since 1990, when just over half of adults were overweight or obese, and showed how more people are becoming overweight or obese at younger ages than in the past. Both conditions can raise the risk of diabetes, high blood pressure and heart disease, and shorten life expectancy.

The study's authors documented increases in the rates of overweight and obesity across ages, and were particularly alarmed by the steep rise among children, more than one in three of whom are now overweight or obese. Without aggressive intervention, they forecast, the number of overweight and obese people in the country will continue to go up, reaching nearly 260 million people in 2050.

The paper defined "overweight" adults as those who were age 25 and over with a body mass index (BMI) at or over 25, and "obese" adults as those with a BMI at or over 30. The authors acknowledged that BMI is an imperfect measure that may not capture variations in body structure across the population. But from a scientific perspective, BMI is correlated with other measures of body fat and is a practical tool for studying it at a population level.