....is key, make sure that you don't deprive yourself!
Drink lots of water. It keeps you full and I find that sipping it through a straw keeps my mouth busy enough that I am not looking for something to eat.
My secret of maintaining my ideal weight over a long period of time has been , small portion size, avoiding deep fried food , and brisk walk 6 days a week without fail.
I carry a bag with two bottles of water in it .... it is like carrying lil weight with you especially when climbing the stairs.
When i have a non diet day, i always have a special treat, which is either, cheese on toast, or melted cheese in microwave, these are nice with a large mug ot tea.