I do find that when I eat whole foods, rather than foods that are lower calorie but more artificial, I lose weight more easily/quickly, even when eating the same number of calories. Obviously this isnt good scientific evidence for a whole food diet, but it makes sense to me. Plus my skin just doesnt like artificial ingredients like colourings, flavourings, preservatives or sweetners, so I have a bias for a whole food diet ^_^ But i would definitely recommend giving it a go. Of course, I still have the occasional meal when I go out or on special events that doesnt match this, or the odd diet coke, but like Joss says, its about moderation in all things.
But yeah, 10 bananas is really not great advice >.< It's not 1000 cals of pure sugar as such, but its definitely around 1000 cals of, well, banana. Counting calories is a good idea, because the deficit is the most bottom line at the end of the day.
How long have you been doing your exercise regime for? it might need some shaking up if its been the same for a while. How tired are you at the end? Are you giving 80-100% in your workouts? Are you pushing your limits each time? Doing that if you arent already might also help
Basically- calorie count (esp that tea!), hard workouts, whole foods- thats how I do it
