This is what has worked for me.
Only healthy carbs - rye bread, wholegrain rice, quinoa, chickpeas, lentils, sweet potatos that sort of thing.
I only eat full fat - milk, cheese, plain yogurt. I really believe the whole low fat diet thing is untrue. Full fat means you get satisfied more quickly and eat less I believe.
I never eat fruit yogurts, cereal bars, certain breakfast cereals as they are full of refined sugar. Porridge or eggs for breakfast.
Three nights a week I eat steamed fish with massive amounts of steamed green veg, been eating a lot of stuff like spring greens, samphire, spinach, purple broccoli. A small amount of fruit like apples, pears and berries in season but no tropical fruit.
I try very hard to avoid anything that is overprocessed, all ready meals etc. Cook from scratch as much as possible.
That plus swimming 2km swims two to three times a week plus one ashtanga yoga class, and I walk everywhere including the school run as I don't drive!
I have at last hit my pre-pregnancy weight, six and a half years later!!