So many things that a person wants to do, wants to be, but they "can't."
Why can't they? Why does a person not like what they do or who they are? Who is in control other than that person? So many people want to lose weight, but continue to eat unhealthily; or else they want to do better in school, but continue to procratinate. In one way or another, most people are unhappy with themselves.
One explaination of this phenomenon is that a person thinks one thing and feels another. One thinks, "I'd like to lose weight," but then they feel hungry, so they eat. It is common for the mind, heart and body to guide in different directions. One's goal, however, should be to stay in this unstable position for as short a time as possible.
Think of these parts (mind, body, and heart) of the self as the the three legs of a tripod. All three legs are necessary to hold up the center (the "self"), but the relative lengths of each individual leg adjust the lean and stability of the tripod center.
An example problem:
A person wants to lose weight. (let's use the pronoun "she" because I was just talking to a girl in exactly this situation). She considers herself "on a diet," but can't seem to stick with it. She wants to lose weight, but keeps getting hungry for a burger, or ice cream, or chocolate. Each time she gives in to her cravings for unhealthy food, she feels terrible. "I have no willpower!" she says. She's angry at herself for being unable to stick to her plan so she didn't even enjoy the unhealty food in question. Result: she's unhappy with her body and unhappy with her lack of will and unhappy with food.
To relate this to the above analogy. The "mind" leg of the tripod keeps falling too short to support the over-long "body" leg which causes the center to tilt over.
If she keeps with the diet, she'll be happy with her body, happy with her willpower, and happy with the food she does eat.
If she decides that the diet is not worh it, she'll be happy with her body, happy with herself for deciding this course of action, and hey - she'll get to enjoy whatever foods she wants.
That's not to say that, in the second case, the woman wouldn't still want a thinner body. The difference is this: She knows the cost. Losing weight comes at the cost of not eating unhealthy (but tasty) food. She makes a decision based on the collective information from her whole being and then has no regrets.
But what if she decides to lose weight but then doesn't stick to it? If she chooses to lose weight, but then realizes that she misses Burger King too much, well, she can re-evaluate her choices. Burger King, she decides, is worth the extra weight.
Why hate yourself for the decisions you make? Especially in a situation as simple as weight loss, a person knows the benefits and knows the costs. If you choose to go for it, go for it. If you decide that you like junk food more than you want a slimmer waistline, so be it. Enjoy that burger and don't feel guilty.
(as a side note to girl readers: damn it, you're not fat)
Sometimes, a person who believes in this philosophy will be called arrogant. The truth is, everyone should believe that he or she is the "best" person they know. If not, who is better than you, and why? What, then, can you do to be like that person? Each person makes the choices that lead to his or her life, abilities, and character. That doesn't mean that no one can be better than you at anything, just that the entirety of yourself is at least as "good" as anyone you know.
Girl from above example envies skinny model on TV... but realizes that this girl is probably anorexic/bulemic and spends all her time at the gym. Those are the model's choices, and they are not the choices that the girl watching TV wants to make. It's her choice to not look like that because the time and effort required would not be worth it. (plus, it's goddam unhealthy and half those girls look like refugees)