Yes, when I was a size 10, people would hold doors open for me, approach me in the street if I looked lost and ask if I needed help, I would be bought/given free food/drinks (not just by dates, by restaurant/bar staff), people would offer to walk me home, carry things if they were heavy, I was offered a free holiday (which I declined - I sensed some rather serious strings attached!). I even had an ikea delivery driver offer to assemble all my IKEA furniture for me!
I also had men grab my tits in bars and on the street, I had a man take his willy out and rub it on me on a bus, I had my drink spiked in a club, I was followed home by a random man twice my age, and was called lots of names by men I politely excused myself from (bitch, stuck up bitch, snooty cow, f'cking c'nt), I had lots of people speak over me in meetings or dismiss my opinions but praise the same opinion when it was repeated 2 minutes later in the meeting by a man.
I'm a size 20 now, but I'm also 20 years older and have a lot more grey hair and a lot less desire to be thought of as "nice" and a lot less worry about upsetting the apple cart. The difference in treatment could be weight or age or attitude.