Not even that, if you change what you eat, you can have a dramatic effect as well. Try cutting out carbs and sugar as much as possible, results in two weeks.
I would suggest to be careful with cutting out things, this leads to bouncing back, like all dramatic changes.
I noticed that carbs such as bread or pasta really help with food satisfaction, unlike fat-intence or protein foods.
Remove sugar in secondary things: tea, coffee, soda. Understand the calorie count in carbs such as chips. East to the mild calorie deficit. Compensate with moderate excercise. And so on, setup new dietary habits one by one.
Changing when you eat is a factor too.