All of the above suggestions are great. Someone mentioned that the "stinky" comment may have simply been observational rather than bullying. When my DD told me someone had said her lunch was gross, I reminded her that she's gotten opportunities to go places, see things, and eat foods than many children haven't been able to, and that's something to be proud of. Maybe OP's DS could offer to share something individually sized out of his lunch with the girl? Or maybe he could invite her to tell him about her favorite foods.
In case it has progressed to bullying, I work hard with my DD (whether I'm successful, who knows) to help her find her voice and not to be a victim. I was bullied as a girl, and I never said a word about it, not to the bully nor to anyone else...and that's the kind of person bullies like to bully. I also think it's a very good idea to work with kids on not bowing to peer pressure long before they get into situations where they're around drugs, sex, etc. I encourage my DD to practice a "Mommy voice": firm, confident, and assertive rather than whiny, angry, or submissive. Might it work to announce to any children giving him a hard time, "It's my lunch, and I like it. Let's talk about ___ instead"?
Good luck!









in fact to them it looks like poop. its a rare child who brings hummus to a traditional public school. 
. (Dd wasn't particularly bothered by their complaints, and it's nutritious and nut free).

taken me 5 years to realise this) - sharing. i now pack some junk so that dd has something to offer the kids. mostly its fruit (a variety since her friends like different fruit) and sometimes a little junk here or there - yes including candy (though we havent made candy sushi yet. she has taken veggie sushi and made converts of some of her friends so i think she wants to take more of her food).
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