My son is seven also, and has the same problem. We were able to find him jeans with an elastic waist at JCPenney's. They're Arizona brand, I think in the store they're advertised as pull-on pants. When I bought them they were on sale for $9.99. The thing I like about them besides the elastic waist is they aren't too long. Cole can wear a 5 regular and they fit fine, unlike most pants that fit in the waist but are way too long.