Weighing bread - gets lighter the older they get

drkim86

I get bread from the Publix bakery and the calories are hard to determine by slice since every one is a different size. Their website says 2 oz of the particular type I get is 76 cals, but I noticed this morning that they weigh a lot less when older and drier. 2 slices of the middle part of the loaf (the bigger slices) weigh around 60 oz when fresh but a week later 2 similar slices will only weigh half of that. Anyone else notice this? Should I just eyeball as I go and stick with the weight of fresh bread?