If we want kids to make better decisions about their health, it helps if they understand whether they're unhealthy to begin with. When it comes to weight, that might not be the case. This is Healthcare Triage News.

We're gonna focus on one story today. It's from last months academic pediatrics, 'Accuracy of Weight Perceptions in a Nationally Representative Cohort of US 8th Grade Adolescents'.

It's no secret that overweight and obesity are a major problem in children, about one in three kids are currently in one of those classes in the United States. Being overweight or obese as a child makes one more likely to be obese as an adult, which of course carries with it its own health risks.

Many think it's all about giving others knowledge about what they're eating so that they can make better choices in the future but of course that's all predicated on the belief that those that are at risk know that they're at risk, so they can use the knowledge your giving them.

Researchers in this study used data from the Early Childhood Longitudinal Study-Kindergarten Class. It started back in 1998/1999, and data has been collected at baseline, then when the kids were in 1st, 3rd, 5th and 8th grade.

This study focused on the 8th grade wave. Besides collecting data from the kids, parents and teachers, height and weight were also measured.

Data from about 7800 kids were available, their average age was just over 14 years, and that was about 43% of the kids from the original kindergarten class - most of the kids who were lost to follow-up had changed schools.

Kids lost to follow-up were more likely to be black or of lower socioeconomic status relative to those who remained in the study, but there were no statistically significant differences in BMI, obesity prevalence, sex or age in kindergarten of those still in or out of the cohort.

The data were weighted so that they were representing - and I'm quoting the paper here - "3 417 969 adolescents in the United States, or about 80% of all US 8th graders in the 2006-2007 school year". You gotta love the precision there.

Overall, over 40% of the adolescents did not perceive their weight status accurately. Just over 35% underestimated it, and just under 7% overestimated it.

The real concerning part though is that most of the misperception is among those who are overweight or obese. 

More than half of overweight adolescents underestimated their weight status. Just under half thought they were normal weight, and more that 3% thought they were underweight.

More than 78% of obese adolescents underestimated their weight status. About 60% of them thought that they were just overweight and another 16% thought they were normal weight. 2% more thought they were underweight.

Unhealthy behaviors were associated with underestimating weight. Adolescents who did underestimate their weight ate 38% more fast food and bought 37% more junk food at school.

Interestingly, adolescents who reported trying to lose weight were not significantly different from those who were not, with respect to their diet and activity behaviors.

I'm not even sure what to do with that! Thinking about those who were trying to lose weight weren't acting or eating any differently from those who weren't makes my head hurt.

It's all well and good to keep putting data and calorie counts in front of people - including adolescents. It doesn't seem to be helping as much as we'd like though, and it's gonna be even harder when so many of them don't see the problem existing in the first place.

Healthcare Triage is supported in part by viewers like you through patreon.com, a service that allows you to support the show through a monthly donation. We'd especially like to thank our honorary research associates, Cameron Alexander and Qadeem Salehmohamed. Thanks Cameron and Qadeem! If you'd like to support the show, more information can be found at patreon.com/healthcaretriage