Keep offering fresh food. A lot of iguanas stop eating when stressed, and relocation is a big stress. It's possible he'll not eat for weeks, but with how skinny he is, keep trying. Bananas are a favorite, strawberries, too. Mine likes those little clementines. Anything now is better than nothing. If possible try to get water into him. Little squirt bottle or syringe and try to squirt some in his mouth.