FH
We have weighed our deer for at least the last 10 years. Over the last 5 years of serious QDM, I can say that I honestly have not seen any change in body weights. Not sure why.
Weights of our deer usually run:
fawns... 35-50lbs
1.5... does 60-80lbs; bucks 75-90lbs
2.5... does 80-90lbs; bucks 90-110lbs
3.5 & up... does 90+lbs; bucks 110+lbs

Honestly we have not take that many deer that we know for sure are over 3.5. We have in the last 10 years weighed over 200 deer. So I'd say the averages are pretty accurate. Up until this year, the heaviest deer ever killed was 121lbs...a 4.5 year old buck. This year, a 4.5 year old buck was taken that was HUGE by comparison....145lbs. We have no idea how or why he was so big. 24lbs bigger than our best ever in over 15 years of hunting. ??? He had a nice rack also...very heavy, and good tine length, but only a 13" spread. I'd say he went around 115"...which is about as good as we've ever taken on our place. We have not changed anything on the property really...just the way and amount of deer we kill. We average over 25 does a year for the last 5 years, and few bucks. Like SAK said, we have not really seen a change in the doe population, but have definitely seen a difference in buck sightings, and especially in the 2.5 and up age group. We regularly see a half dozen or more nice symetrical 8 points that are 2.5 with around 13-15" spreads. Of course....seeing those same deer the following year always seems to prove a challenge. I think they really get smart between 2.5 & 3.5 Not sure why the body weights haven't changed....but our place is in line with what ends up at the check in stations each year weight wise. I imagine some of the properties around have heavier deer because of better nutrition, but there are few checked in each year over the 140 mark.