I am absolutely hopeless at 'portion control'. If I like to eat or drink something then I either have lots of it, or none of it, not somewhere in between. I am constantly amazed at how some people can make a 125g bar of Fruit & Nut chocolate last a week...
That's 6 minutes worth isn't it? 
As long as I don't start something more-ish, I am fine.
It is why I had to give up alcohol. I'd have a swift half, but then rapidly progress to another 5 or 6 pints. Yes, that
WAS a reduction from the 10-12 pints that I would have had in an evening as a young man, but only because my body couldn't handle that much beer any more.
It's over 9 years since I gave up the booze and normally I don't miss it, but tonight I got a text from someone thanking me for the 3 bottles of bitter that I had bought him for Christmas. He included a photo of the 3 different ales. I hadn't bought the beer in person, rather I had provided the money for the beer to be bought on my behalf. I actually started salivating looking at the bottles! Wow, I fancied settling down to watch a film with those by my side. I can't trust myself though - I'll settle for a nice mug of tea instead!