For many of us the word "diet" conjures up images of deprivation, hunger pains, and boring meals. But the word "diet" actually doesn't refer to "going on a diet..." it actually means what we eat. If you want to lose weight and improve your health, you're going to have to stop thinking in terms of, "I'm going on a diet next week."
Instead, you're going to have to focus on the sorts of foods you should be eating each day to maintain good health, and forget all that nonsense about calorie consumption etc. etc.
One of the biggest difficulties that strikes many of us, however, is that we're really not sure where to begin. Because of this, we do try and follow particular diet plans and regimens, which are often difficult and restrictive. Instead, we need to learn more about healthy eating and how to integrate healthy eating into our day to day lives. Sometimes it's helpful to just buy one book, or follow one particular healthy eating plan, until you know instinctively what you should be eating and when you should be eating it. Don't try a new diet each week in the hope that this one will be the one that finally takes your fat away for good! You know as well as I do that most diets can't live up to what they promise. Instead, find a resource that educates you about healthy eating.