There’s a lot that contributes to a persons weight. Especially with kids it’s not as simple as telling them eat less and work more.
With growth spurts, hormones, genetics, mental/emotional health, adolescents and a bunch of other stuff a kids size/weight can be up and down.
I think for kids it’s best to lead a healthy lifestyle by example and not get so caught up in their weight or appearance.
My 17 year old daughter was severely underweight this time last year. No eating disorder just bad/unhealthy eating habits. It’s been hard to navigate getting her to eat more food without messing up her self esteem and confidence. She’s doing a bit better now, but at times i still literally have to remind her to eat.
My 12 year old son on the other hand has been chubby his entire life. He’s always been very active, plays soccer and football. Goes on walk/runs with me, but was just chubby still. Would get comments from the doctor about losing weight.
Over the last six months or so he just randomly hit a growth spurt and now he’s all tall and kinda swole for his age.
We are a relatively healthy family. We don’t eat all kale and tofu, but i cook most nights and i try to keep it somewhat healthy.
The main point i’m trying to make here is that under the same conditions i have two kids on very opposites sides of the subject. As a parent if you are worried about your kids weight, the best thing to do is to concentrate on health. Their weight is gonna fluctuate throughout their childhood. The goal should just be to make sure they are equipped with healthy habits and healthy self esteem/self worth for when they are adults.