If you want to reduce co2 intake and photosnythesis, sure.. i.e. no, don't do that.
Read "to defolialte or no..." on cocoforcannabis.com to rid yourself of any urban myths related to defoliation.
the producets of photosynthesis are ever present throughout the phloem. Distribution is based upon apical dominance and not where the light hits the plant. ATP et al is highly mobile.