Diets do work; but you've got to be patient and consistent.
Basically: put less in your face.
Over about a thirty month period I went from 120 kgs (265 lbs) to 80 kgs (176 lbs.)
I did it by dishing up my own meals, using a smaller plate, and not going back for seconds.
My eyes and brain told me I had a plateful and my subconscious accepted that.
And in just over two years I lost a third of my body weight.

(Sorry for the hijack! I'll butt out now...)