Total Noob question

I was at a friends house the other day, and he trims his sugar leaves and all of his water leaves are cut in order to promote thicker bud site growth? Is this true? Or is he full of shit?

Now ask him where all his buds are getting there energy from. The leaves are where the plant stores essential sugars and nutrients so it can photosynthesize and GROW. All that does is starve the flowers