Hi Indian Girl: Nice to see you over here! I'm Jbird on the Shangri-La Forum. I wonder if your success with a banana at breakfast has to do with "resistant starch," which is found in unripe bananas and cold, cooked starches such as potatoes and porridge. Here's a Wikipedia article on the concept, which has been noted to have some benefit for weight loss.
http://en.wikipedia.org/wiki/Resistant_starch. I wonder if you tried a riper banana, whether you'd notice the same good effects. May be worth trying, but then again, why tamper with success? Glad it's working for you! Jaye