I don't want to sound preachy, I'll just tell you what happened to me and what I did/do.
When my DH died I comfort ate for a while and went up three dress sizes. My GP warned me, if I continued to add weight I would struggle to get it off then keep it off. He recommended a lifestyle change not a diet. I am older and do gentle exercise such as walking or swimming but have changed my diet all together. Today I've had:
Breakfast: Strawberries, raspberries and blackberries with Greek yogurt and flaxseed.
Lunch: A multiseed wrap with lettuce, cucumber, red and yellow peppers and red onion. I often add tuna but didn't today.
Dinner: Steak, sweet stem broccoli, cauli, sprouts, green beans and savoy cabbage.
Snacks: Today I had grapes but nuts are good too. I also had a couple of caramel rice cakes (soothes my sweet cravings).
This helped me get the weight off and (so far) keep it off. The idea is pack yourself as much as possible with veg as it's low calorie and as much as possible cut out processed food.
Like I say, please don't take this as me being preachy or smug it's just what helped me to lose then maintain my weight and I've posted it in the hope it helps you too. 