Objective To examine whether adolescents’ weight perception accuracy (WPA) was associated with extreme weight-management practices (EWPs) in differing body mass index (BMI) categories. Methods WPA, overassessment, and underassessment were determined by comparing self-reported BMI and weight perception among US high-school students in the 2009 National Youth Risk Behavior Survey. BMI was classified as: underweight (<5th percentile), healthy weight (5th–<85th), overweight (≥85th–<95th), and obese (≥95th). WPA was considered inaccurate if BMI and weight perception were discordant. Overassessors thought they were heavier than they were (among underweight/healthy groups); underassessors thought they were lighter than they were (among healthy/overweight/obese groups). EWPs included one or more of fasting, use of diet pills, or purging/laxative use. Logit models were fitted for different BMI sex strata. Results In the final sample of 14,722 US high-school students with complete data, 20.2%, 85.7%, 5.8%, and 80.9% of those who were underweight, healthy weight, overweight, and obese, inaccurately assessed their weight, respectively. In turn, 11.4% and 17.6% of accurate and inaccurate assessors engaged in EWPs, respectively. After adjustment, underweight females who overassessed their weight had 12.6 times higher odds of EWPs (95% CI: 3.4–46.6). Also, there were elevated odds of EWPs among healthy weight students who overassessed their weight. Conclusions Overassessing healthy weight students and underweight girls had higher odds of 3 EWPs, likely related to an unhealthy desire to lose weight. This study demonstrates a need to further educate clinicians on WPA and its relationship to EWPs even among those of healthy weight who may be seen as non-risk.

Increased physical activity consisting of jog-walking 2.5 miles and 1 hr of calisthenics/week was the primary focus of a 17-week weight reduction program in 22 obese (X = 40% body fat) women ages 30 to 52, many of whom had failed at previous attempts to lose weight by dieting alone. Regular exercise was also increased substantially on an individual basis. Caloric restriction was self-determined and was generally moderate, accounting for about 60% of the total mean energy deficit. Initial and final evaluations included body composition by hydrostatic weighing, progressive multistage exercise testing, and plasma lipid and lipoprotein analyses. A mean relative body fat reduction of 5% (P less than or equal to 0.001) was achieved by a drop in fat body weight (X = 5.4 kg; P less than or equal to 0.001) which closely paralleled that of total body weight (X = 4.2 kg; P less than or equal to 0.001). Mean heart rates and systolic blood pressures at identical submaximal exercise intensities were significantly lower at the time of reevaluation. Mean plasma triglyceride and total cholesterol concentrations did not change significantly (P greater than 0.05). However, the high-density lipoprotein cholesterol/low-density lipoprotein cholesterol ratio increased significantly (P less than or equal to 0.05). Increased physical activity combined with moderate dieting is a feasible approach to weight reduction in middle-aged women.