How To Stay Slim.

My Mom always say, when you are slim, don't over eat.
Once you are over weight, it is very difficult to slim back again.
Well, my best friend is very very thin. I am a little over weight.
He eats more meals than me, takes five bowls of rice while I can only consume two bowls.
He can two kilos of mutton for a single meal while I can only eat a small slice.
He drinks three bottles of coke at a single meal while I can hardly finish a bottle of coke.
For years he has been so skiny thin while I have a had time to slim in shape.
What is actually happening to both of us? He wants to put on weight but cannot.
I am just the opposite.
Why?
Recently I came across a doctor with a proven method of getting slim but I am not convince.
I want to know whether it is true before I try it out.
I don't trust her testimonies cos they might not be true.
I wonder if you friends out there have any ideas or maybe have tried it out, please tell me the truth.
check it out here.