to lose weight, to slim down
Ella está a dieta para adelgazar.
She is on a diet to lose weight.
Es una lástima que yo no tenga que adelgazar.
It's a shame that I don't have to lose weight.
Quería adelgazar y pensó que fumar la iba a ayudar.
She wanted to lose weight and thought smoking would help her.
Ella está intentando adelgazar.
She is trying to lose weight.