Loosing power on accelaration

Hello, kia sportage auto on accelaration she has got no balls, she struggles to take off, is there a problem with the timing belt and if there is can or someone tell me how to deal with this issue or is it not the timing belt?
cheers
ian

May be some more explanation is needed...is that a new condition ? If a change,was it sudden or was it a slow progression....I do not want to be cynical ..but sounds like mine has ever been....
Serious, frequently, similar degradation is linked to clogged catalytic...but anyway, send more details , codes, etc.....