No need to exercise at all. It's all about diet. This is something that pretty much everyone agrees on.

Exercise can help weight loss, but if your diet is bad even exercise won't work.

Remove all processed foods, at least all white sugar and refined oils.

Eat only food that physicaly existed 200 years ago (minus sugar that rich people could afford in large quantities only). Removing white sugar and white flour and processed oils and all processed sweets is the safest best.

TLDR: eat whole foods.