As a lifetime fat person the best decision I made was to go on a paleo diet. Essentially: No grains, no legumes, no processed food, no dairy. Limit intake to : grass fed meat (when possible), veggies, some select nuts, limited fruit.

That in combination with stopping drinking, eliminating pop and just adding some mild walking has made a huge impact. I don't worry about portion size, counting calories etc.

If you are like me, you might want to check paleo out.