When I finally stopped to smoking last November I gained 12 pounds within 4 months and I was 152 pounds(almost 70kg) in March. No diet is working so I changed my diet to paleo. Now I exercising 5-6 times a week(40-50 minutes a day), swimming 2-3 times and I do hula hoop and kangoo jump while I watching TV.
I use just xylitol instead of sugar.(Expensive but worth it) I don't do the very strict paleo so I eat pasta or rice or a few cookies but max 2-3 times a week. I bake my own bread . Now I lost 15 pounds since March and I'm in good shape(138 pound=63kg and my BMI is 21) and I feel good. I don't want to lose more weight because my tits will be smaller then and I'm not a fan the six packs on women (and men either). You don't have to lose your weight very fast because it's coming back easily(jojo effect) but 3-4 pounds a month will be permanent.
So exercise and paleo are working together.
Try Stevia (now brand). 10 bucks lose form. I love stevia. I like it more than sugar for my coffee. Learned about Stevia way back in the day when I was in Brazil. Over there they don't use sugar, they use Stevia. I am glad it caught on in North America.