Julia that was one of the first things I noted. How clever! We don't tend to check how much is in the packets we buy. What's 100gm less to a busy mum? 100 gm less in every pack means a lot more in the bank for greedy profiteers.
And now it's worse. I can't go back in time and prove it, but I opened up a pack of ground beef which was decidedly smaller than usual. I don't use scales at home, but the store had reduced the packs by a whopping 50 cents, and I'm pretty sure had reduced the weight of the beef.
The girls working in the supermarket advised me to weigh everything. Sigh!