No I would not starve him so he eats greens, at 5 months your beardie needs more protein then greens. some tips to get your little one eating greens- one of mine love their veggies sprayed with baby juice, one of mine did not start eating her greens until I had the Temps and lighting perfect now she will eat some. or add small worms to his greens so when he takes a bite he gets a veggie?
Good Luck.