Male panthers seem to need a lot more crickets than a male Senegal does. You should be able to tell when the chameleon is looking fat and realize that you need to cut back.
I gutload/feed crickets with a wide assortment of greens (dandelions, kale, collards, endive, escarole, mustard greens, etc.) and veggies (carrots, squash, sweet potato, sweet red pepper, zucchini, celery leaves etc.).
IMHO, a phos.-free calcium powder should be dusted on the insects before they are fed to a chameleon at most feedings to make up for the poor ratio of calcium to phos.
I dust twice a month with a vitamin powder that contains a beta carotene source of vitamin A and twice a month with a phos.-free calcium/D3 powder lightly.