There's not just one contributing factor to obesity. Calorie-in vs. calorie-out gets a ton of warranted attention. Beyond that, things such as stress affect how efficient one's metabolism is. Stress specifically affects hormones such as cortisol in kids that can lead to changes in how their bodies use glucose, and changes are not necessarily good.
We may not need lab work to identify stress. Eating habits oftentimes can be a good indicator. Stress takes the cake as far as emotional eating (from anger, boredom, etc.) is concerned. Physicians say that being mindful is key in managing stress and any emotional eating effects that come along with it.
Ways you can be mindful to stay healthy:
Registered Dietitian, Austinite, Mom with a 2-yr old, Dog lover