There may be something in that theory! Girl in work swears that when she's been on a diet in the past she's had to cut out the bananas as they halt her weight loss!
I'm trying a little experiment myself at the mo - used to have one banana every day for brekkie with a yogurt - didn't have one at all last week and lost 4.5 (but it was my first week ). I've had a couple of bananas this week but I'm not going back to having one every day.
I had the same weight loss last week a non banana week, than the week before a banana week. Spoke to my c about this and she said its a load of rubbish, bananas are goo so long as you dont OD on them. She said it shouldnt make any difference, so I am back on them again. W I tomorrow.