Despite attempts by many Americans to control their weight, the prevalence of obesity continues to increase. We investigated the prevalence and predictors of weight control attempts and specific weight control practices in U.S. adults. We analyzed self-reported data from the National Health and Nutrition Examination Survey (2001-2002), representative of the civilian noninstitutionalized U.S. population. We limited our analysis to nonpregnant adults aged ≥20 years (n=4766). Using SUDAAN, we performed multivariate logistic regression to identify the predictors associated with attempting to control (lose or not gain) weight the previous year. Forty-four percent of men and 57% of women attempted to control their weight. The odds of attempting to control weight were significantly higher among adults who were more educated (>high school versus <high school) (odds ratio [OR]=2.2; 95% confidence interval [CI]=1.7-3.0), had never smoked (versus current smoking) (OR=1.5; CI=1.2-1.9), and were obese (body mass index 1 year ago ≥30 kg/m² versus <25 kg/m²) (OR=5.5; CI=4.6-6.5). The odds were lower among older adults (age ≥60 versus 20-39) (OR=0.58; CI=0.47-0.70) and among non-Hispanic blacks (versus non-Hispanic whites) (OR=0.62; CI=0.49-0.80). Among 2,174 adults who attempted to control their weight, only 28% reported both meeting physical activity recommendations (≥20 minutes vigorous activity ≥3 times per week or ≥30 minutes of at least moderate activity ≥5 times per week) and either eating less food or switching to lower calorie foods. Although over half of adults attempted to control their weight, the vast majority who tried did not meet minimal recommendations for physical activity and dietary restriction.