agreed. the leaves may seem to be using up all the nutes and water, but theres a few reasons why. the leaves are needed for natural photosynthesis and they also help with the exchange of gases. the plant cannot be healthy if these natural processes cant be done due to loss of leaves. i havent heard anyone else mention this as a reason, but just from watching my last few harvests, after flushing your medium of nutes a few weeks before harvest, the buds pull the nitrogen they need from the fan leaves since it can no longer get it from the medium. thats why the large fan leaves all turn yellow and look sick. so again to agree with everyone else, do not cut them off, just tuck them. and if you tuck them too tightly and they lose most light to them, they'll start to die off anyway.