Fadi
...
I agree with you up to a point then I would say this...However, personally I think I would have a hard time listening to a trainer trying to tell me how to loose weight, unless they had been overweight themselves once and through their techneques lost the weight.
Yes, it's great to speak from a point of: "been there done that", however if one was to look at that attribute as a positive, then one would also need to be aware of some negativity. What could that be you may ask?
The way he (the trainer) lost his weight. You see, as long as you are aware that what has worked for him would not (or may not) necessarily work for you, understanding and being aware of that fact would have you in a better position instead of listening to the man and doing it all his way because well... it has worked for him. Some overweight people rely on diet while others rely (or place more emphasis rather) on caloric expenditure through working out and speeding their metabolism.
If I sound like I’m disagreeing with the thrust of your message, then please know that I'm not. I agree with you but I would just place a mark of "be aware" if you like when listening to people who've been there done that. That's all really.
Fadi.