One thing I've always noticed about people who fail at diets is they try to go all out towards a goal which will create immediate results. When these people don't get the results they're looking for they quit, determining it's just too much time and effort to go all out just to fail.
The whole point of taking small consistant steps towards dieting is to be able to see immediate results that are designed to succeed. You might not be able to cut out that 4 packs of sugar in your coffee all at once, but you definately can cut out 1 pack. Or half a pack, how about a quarter of a pack? The point is to make things so small you can't help but succeed.
Some people will have the attitude this will not accomplish much, but the reality is it will accomplish much toward consistant dieting. People trying to approach a diet with an all or nothing attitude, rarely succeed because they bog themselves down in seeing the all or nothing
Think small attainable steps for your diet and fitness program, ones you can definately succeed at and you will be surprised at how each step moves you closer and closer to your ultimate goal.