YY to Nellyjob, any kind of activity is good - even just a simple brisk walk 3 or 4 times a week.
Have to had a go at low a carb/high fat/high protien diet such as Paleo or lchf Swedish diet?
You don't count calories, or avoid fat, eat lots of protein, and it breaks that constant snacking cycle you often get with a low fat, low protein diet - because you don't get the blood sugar highs and lows.
Things to avoid - all grains and grain flours, but especially wheat, starchy root veg (if you eat them, very small quantities), and very strictly limit all sugar (glucose, fructose. lactose (milk sugar), dextrose, anything with "-ose" at the end of the word!).
Here's the funny thing. Eat protein and fat based meals. don't limit the amount you are eating except in a very relaxed way (ie serve a handful of nuts at a time, not a whole packet), and without all the sugar/carb to spike your blood sugar (then crash it) - you won't snack the way you do now.
It works!