More than half of adolescents with type 2 diabetes underestimate their weight, and so do their parents, according to results from interviews with 104 child-parent pairs.
“Clinicians should recognize that even extremely overweight children and their parents may not accurately perceive the presence of weight problems, let alone the negative consequences of failing to make difficult lifestyle changes that result in weight loss,” wrote Asheley Cockrell Skinner, Ph.D., of the University of North Carolina, Chapel Hill, and her colleagues.
Recognition of overweight is essential for adolescents with diabetes so they can make diet and exercise choices to lose weight and reduce their risk of complications associated with the disease and with overweight, the researchers said.
To determine the accuracy of weight perception in adolescents with type 2 diabetes and the impact of their perceived weight on healthy behaviors, the researchers interviewed 104 adolescents aged 12–20 years, and their parents, by telephone. The average weight of the study population was 221 pounds; 69% were girls and 47% were black. The average hemoglobin A1c level was 7.7%, and most were taking insulin, other medications, or both.
Overall, 87% of the adolescents met the Centers for Disease Control and Prevention's criteria for overweight, and the group's average body mass index was 36 kg/m
In parents who said the child's weight was “about right,” 40% had children whose BMI was in the 95th percentile or higher; 55% of adolescents who said their weight was “about right” had a BMI in the 95th percentile or higher.
Adolescents were significantly more likely to underestimate their weight if their parents also underestimated it, compared with adolescents whose parents accurately estimated their weight (66% vs. 34%).
“Previous studies have shown that parents and adolescents often underestimate weight status, [but] we were surprised that in this population, where the adolescents were generally very overweight and already had type 2 diabetes, underestimation of weight status was still very common,” Dr. Russell Rothman, study coauthor and deputy director of the Diabetes Research and Training Center at Vanderbilt University, Nashville, Tenn., said in an interview.
“Underestimation of weight was also associated with poorer dietary behaviors and more perceived barriers to following a healthy diet and exercising,” he said.
The interview results showed that, overall, adolescents who underestimated their weight were significantly less likely than were those who estimated their weight correctly or overestimated to report healthy eating behaviors (31% vs. 52%) and exercise (27% vs. 44%). And parents who underestimated the adolescent's weight were significantly less likely to report that the adolescent exercised than were those who estimated the adolescent's weight correctly or overestimated it (26% vs. 46%).
No significant differences in weight perceptions according to race or insulin use were noted by parents or teens. Girls were significantly more likely than were boys to underestimate their weight, but the accuracy of the parents' estimates was not significantly different for boys versus girls.
Weight estimates by parents and adolescents were least accurate for adolescents aged 13–16 years compared with those older than 16 and younger than 13, but these differences were not significant (Diabetes Care 2008;31:227–9).
Dr. Rothman said although the findings seem obvious, they are worth noting so that doctors will raise the subject of weight with teen patients and ask about healthy eating and exercise.
He advised clinicians to practice shared goal-setting to help the adolescent set specific goals and then identify specific barriers. The next step is to guide the adolescent in problem solving, which will improve his or her self-management. “Try to avoid a lot of jargon and keep communication simple, clear, personal to the patient, and culturally sensitive,” he said, adding the entire family should be in the process of diabetes management.
The researchers were funded by awards from Vanderbilt University, the National Institutes of Health, the Agency for Healthcare Research and Quality, and the Department of Veterans Affairs.