Make a list of the reasons why you want to be thinner. Keep the list posted on your fridge, at your computer, on the bathroom mirror...wherever you will see it regularly.You have to learn to manage it: keep your focus and motivation strong. Eating habits are hard to change because you have to make choices everyday and several times a day.  This book may be useful : The Mindful Meals Diet: A mind/body plan to develop new healthy eating habits.