The categories of normal, overweight, and obese are entirely arbitrary and at odds with the underlying evidence about the association between body mass index and mortality. Regardless, the average population weight gain in the United States in the past 42 years is 10.9kg or 0.26kg a year. Yet, between 1999-2000 and 2001-2002, there were no significant changes in the prevalence of overweight or obesity among US adults or in the prevalence of overweight among children. However, it must be noted that the risks of obesity on many serious health conditions including high blood pressure, diabetes, heart disease and some forms of cancer, are serious and well established.