Extensive guest post on "Healthy Low Carb Kids".
Many suggestions for lunch box, meals, parties, eating out, etc.
Links to her recipes and kid lunchbox photos, etc.
So much information on the DitchTheCarbs website, and you can link to it all through this one post:

https://lowcarbrn.wordpress.com/201...-low-carb-kids/

This is a really hard issue. My middle child is in this category. She's 10 and always hungry and very big. Thing is, she eats the exact same food as the rest of us and my other children are thin, even maybe a little underweight (my oldest). We've been grain free and low carb for years. They certainly get junk from my mother but there are pretty serious limits on what that junk looks like. After severely curtailing any carbs at all earlier this year for all the kids due to a cavity scare (she's the only one who's had one), it didn't really make a difference at all except to drop my oldest's weight who didn't need to lose any at all. I don't actually care that much about her weight but she's kind of run down, has frequent stomach upset and just doesn't feel like a 10 year old should feel, with energy.

I'm at a loss now, frankly.