How to get in laws to stop with food comments to my daughters?

My daughters are fine. They just have big appetites, always have. They must have fast metabolisms because they’re thin too but they could probably eat all day without breaks. But I don’t say anything... they’re growing. They’re fine. They’re thriving. It’s all healthy food. Some kids are just like that, so was my husband. But my in laws! Man, they will say “are you a bottomless pit!?” “You’re STILL eating???” “Will you ever be full!?”

How do I shut that down without drawing too much attention to it so my daughters don’t realize? I’ve tried talking to them in private and saying I don’t want to draw attention to how much they eat because I don’t want body image issues. Thoughts?