Increased prevalence of Obesity (left panel) and GERD (right panel) among US adults. The age-adjusted prevalence of overweight (BMI 25-30 kg/m2, black diamond, dashed line), obesity (BMI > 30 kg/m2, white square, black line) and extremely obesity (BMI > 40 kg/m2, black triangle, black line) increased from 1960 to 2006. This survey includes subjects aged from 20 to 74 years (source: Department of Health and Human Services. Centers for Disease Control and Prevention.http://www.cdc.gov/nchs/data/hestat/overweight/overweight_adult.htm [30]). The time trends of hospitalization for gastro-esophageal reflux disease also increased in the US Department of Vetrans Affairs from 1970 to 1995 [31].