Is “Permanent Weight Loss” an Oxymoron?
The Statistics on Weight Loss and the
National Weight Control Registry
In view of the statistics on “obesity” and dieting in the United States, “permanent weight loss” might seem oxymoronic. Despite our collective efforts to lose weight, the average American continues to gain. For example, in 1991, the average U.S. man weighed 179 pounds, and the average woman weighed 143 pounds. In 1998, average weights for U.S. men and women were 186 pounds and 151 pounds, respectively (Mokdad et al., 1999). Prevalence of “obesity” among U.S. adults increased during the 1990s from approximately 23 percent at the beginning of the decade to 31 percent in 2000 (Flegal, Carroll, Ogden, & Johnson, 2003). The most recent data from the National Health and Nutrition Examination Surveys indicate that between 1999 and 2004 the prevalence of “obesity” continued to increase slightly for men, although no overall increases in prevalence rates for women were observed during this six-year period (Ogden et al., 2006).
During much of the time period covered by these studies of the national prevalence of weight gain and “obesity,” large-scale surveys also indicated a high prevalence of weight loss attempts by Americans. In the early 1990s, 33–40 percent of U.S. women and 20–24 percent of men reported that they were trying to lose weight (NIH Technology Assessment Conference Panel, 1993). In 1998, approximately 44 percent of U.S. women and 28 percent of U.S. men indicated that they were trying to lose weight (Serdula et al., 1999). The 2000 Behavioral Risk Factor Surveillance System Survey (BRFSSS) revealed that these numbers increased further by the end of the decade, to 46.3 percent of women and 32.8 percent of men trying to lose weight (Bish et al., 2005). Additionally, the data indicate that the prevalence of weight loss attempts increased directly with body mass index (BMI), such that the prevalence of trying to lose weight among women with BMIs between 25 and 29.9 was 60 percent, and among women with BMIs greater than 30 it was 70 percent. Similar trends were observed for men. The fact that average body weights and “obesity” prevalence were increasing at a time of increased weight loss attempts suggests that weight loss was not successful.