In C.S. Lewis's fourth Narnia book, The Silver Chair, the protagonists (two children and a Marsh-wiggle) are faced with a dilemma regarding the title object. To wit, they met an eloquent and quite sane-seeming young man, who after a while reveals that he has a mental disorder: for an hour every night, he loses his mind and must be restrained in the Silver Chair; and if he were to be released during that time he would become a giant, evil snake (it is a fantasy novel, after all). The heroes determine to witness this, and the young man calmly straps himself into the chair. After a few moments, a change comes over him and he begins struggling and begging for release, claiming the other personality is the false one. The children are nonplussed: which person(ality) should they believe? And (a separate question) which should they help?
In the book this dilemma is resolved by means of a cheat*, but we in real life have no such thing. We do, however, have an abundance of Silver Chairs, in the form of psychotropic drugs from alcohol to hallucinogens to fancy antidepressants and antipsychotics. Of course not every person who takes such drugs is in a Silver Chair situation, but consider for instance the alcoholic who insists he doesn't have a problem, or the paranoid schizophrenic who fears that any drug is an attempt to poison him. Now we as observers or authorities may know from statistics or even from their personal histories that the detoxxed/drugged-up versions of these people would be happy for the change and not want to return to the previous state, but does that mean it's right (in a paternalistic sense, meaning for their own good) to force them towards what we call mental health?
I would say it is not, that our preference for one side of the Silver Chair over the other is simple bias in favor of mental states similar to our own. From our places near normality we can't imagine wanting to be in these bizarre mental states, so we assume that the people who are in them don't really want to be either. They might claim to, sure, but why believe them? After all, they're crazy. For two amusing thought experiments in this line which have been considered in detail by others, let the bizarre mental state in question take the values "religious belief", and "sense of humor". For a sobering real-world application, consider the fate of homosexuals until a few decades ago. And then think about how, as Eliezer has said, the future like the past will be filled with people whose values we would find abhorrent.
This idea has internal relevance as well. You could easily consider, for instance, the self introspecting at home who wants to lose weight and the self in a restaurant who wants to order cheesecake as two sides of a Silver Chair**. And I think that view is more helpful than just calling it "akrasia", because it presents the situation as two aspects of your personality which happen to want different things, instead of some "weakness" which is interfering with your "true will". Then instead of castigating yourself for weakness of will, you merely think "I suppose my desire for cheesecake was stronger than I anticipated. When I return to a state where my desire to lose weight is dominant, I shall have to make stricter plans."
Again, I see a bias: we think that the desires (and in fact the entire mental state) which we have while, e.g., sitting alone calmly in a quiet room are the "true" ones, or even the "right" ones in some moral sense, and that feelings or thoughts we have at other times are "lesser" or akrasic, simply because at the time when we're introspecting we can't feel the power of those other situations,† and of course we rightly privilege our calm-quiet thinking for its prowess in answering objective questions. We spend (presumably) the bulk of our lives not engaged in quiet introspection, so why should we defer to what our desires are then?
Of course, one can always say "When I calmly introspect and plan things in advance, I end up happier/more successful than if I were to give in to my impulses". To which I would respond "That's fine. If happiness or success is what you want, and that method is effective, then go for it."‡ My point is that, just as you shouldn't condemn someone else for not conforming to the desires or thought patterns you think they ought to have, much less force them to conform, neither should you condemn yourself. Your utils come from doing what you want, not being happy or successful, or finding the most efficient way to satisfy as many of your desires as possible, or anything else.
This idea also seems to have relevance to the topic-which-shall-not-be-named, but I guess this isn't the time for that.
* Specifically, the chairbound personality invokes the Holy Name of God, which breaks the symmetry. Not a solution many readers of this site would go for, I think.
** That phrasing is admittedly quite awkward; I guess the two sides would be "(sitting) in" and "out" of the chair.
† I once read that brain scans show that one cannot remember the sensation of sex/orgasms in the same way one can remember other more ordinary sensations. That doesn't jive with my personal experience, but if true I think it gives interesting evidence. A related phenomenon sometimes mentioned by poets (and which I have experienced) is that as you fall in love with someone, you actually find it harder to remember what they look like.
‡ One can also object that impulsive desires are incoherent: e.g. hyperbolic discounting. But I would say that incoherence is a property of epistemic systems, i.e. things that must be explained by other things. A desire doesn't need to be explained by anything or agree with anything; it merely is. And paradoxes of wanting both X and !X don't seem to arise (or if they do, you can always kick in some rationality at that point).