More adolescents are underestimating their weight, study finds

Key takeaways:

• Underestimation of weight status increased while overestimation decreased among youth.
• Girls were less likely to underestimate their weight compared with boys.

The global prevalence of adolescents who underestimate their body weight increased within the last 2 decades, which could hurt engagement in weight reduction efforts, according to researchers.

“During this impressionable age, body weight perception may influence a young person’s lifestyle choices, such as the amount and types of food they eat and their exercise habits,” Anouk Francine Jacqueline Geraets, PhD, a postdoctoral researcher from the department of social sciences at the University of Luxembourg, said in a press release. “So, it’s concerning that we’re seeing a trend where fewer adolescents perceive themselves as being overweight — as this could undermine ongoing efforts to tackle increasing levels of obesity in this age group.”

Misperceptions in body weight perception (BWP) are common in youth and have been linked to mental health conditions and changes in weight status, Geraets and colleagues wrote in Child and Adolescent Obesity.

“Young people who underestimate their weight and therefore do not consider themselves to be overweight may not feel they need to lose excess weight and, as a result, they may make unhealthy lifestyle choices,” Geraets said.

The researchers examined 2002 to 2018 data from WHO’s cross-sectional cross-national study, Health Behavior in School-Aged Children, to establish trends in BWP, adjusting for country, age and gender. The final cohort included 746,121 adolescents aged 11, 13 and 15 years from 41 countries. Among them, 51% were girls.

Geraets and colleagues found that 13.7% and 25.4% of adolescents underestimated and overestimated their weight status, respectively. Although underestimation of weight status increased over time among both genders, the trend was slightly stronger in girls (OR = 1.022; 95% CI, 1.02-1.024) compared with boys (OR = 1.015; 95% CI, 1.013-1.016), according to the researchers. Meanwhile, overestimation of weight decreased in both genders, with the trend also stronger in girls (OR = 0.985; 95% CI, 0.984-0.986).

Over time, boys showed a decrease in correct weight perception (OR = 0.995; 95% CI, 0.994-0.997) and girls showed an increase (OR = 1.007; 95% CI, 1.006-1.008).

Although overestimation, underestimation and correct perceptions varied by country, “changes over time in country-level overweight/obesity prevalence during the years of observation did not explain the overserved changes in BWP,” the researchers wrote.

Geraets and colleagues noted that gender differences in BWP trends may support the idea of gender differences in body ideals and the subsequent changes in those ideals over time.

“Notably, the increased underestimation and decreased overestimation of weight status over time for girls may be explained by the emergence of an athletic and strong body as the new contemporary body ideal for both boys and girls,” they wrote.

Geraets said the study has several clinical and public health implications.

“The increase in correct weight perception and the decrease in overestimation may have a positive effect on unnecessary and unhealthy weight loss behaviors among adolescents, while the increase in underestimation might indicate the need for interventions to strengthen correct weight perception,” she said.

Such interventions could include WHO’s “best buys” for prevention and control of noncommunicable diseases, the researchers wrote, although “policies and interventions need further implementation.”

“More research is needed to understand the factors underlying these time trends and to develop effective public health interventions,” they concluded.

References:

• Fewer teens now perceive themselves as overweight – international study of more than 745,000 adolescents. https://www.eurekalert.org/news-releases/994002. Published July 3, 2023. Accessed July 3, 2023.
• Geraets A, et al. CHAO. 2023;doi:10.1080/2574254X.2023.2218148
• Tackling NCDs. https://apps.who.int/iris/bitstream/handle/10665/259232/WHO-NMH-NVI-17.9-eng.pdf. Accessed July 5, 2023.