Monday’s medical myth: don’t worry, kids will grow out of their ‘puppy fat’

Being overweight or obese can increase a teen’s risk of developing a number of diseases. Cindy Shar-pei

Picture this common scenario: A mother is worried about the size of her 13-year-old daughter, who appears quite a bit heavier than the other students in her class. But the mother is reassured by her friend that it’s only puppy fat and her daughter will grow out of it. So no efforts are made to examine, and potentially alter, the girl’s diet or levels of physical activity.

So is “puppy fat” a true phenomenon? Do young people who are overweight during puberty usually grow out of it?

Let’s consider the evidence.

A 2010 study that monitored the weight status of 900 children in Victoria found those who were carrying excess weight in primary school were likely to still be carrying the excess weight in later high school.

The children were first seen between the ages of five and 10, and were followed up eight years later. One in five of the students were persistently overweight or obese in both mid childhood and adolescence, with some additional young people developing excess weight for the first time in their teen years.

If excess weight in adolescence wasn’t associated with any health problems, there wouldn’t be cause for concern. But adolescents who are overweight or obese are more likely to have a range of risk factors for heart disease and related problems, just as they are in adulthood.

In a NSW study of almost 500 school students aged 15 years, overweight or obese boys were more likely to have elevated blood pressure and cholesterol, abnormal levels of insulin (suggesting a form of pre-diabetes) and poor liver function, than boys whose weight was in the healthy range.

Similar findings were found among adolescent girls, although they weren’t as pronounced.

Overweight and obese boys are at greater risk of heart disease and diabetes. FBellon