That uncomfortable feeling is your critical factor rejecting that information. If I say “the sky is blue and the grass is green” you’re probably comfortable with that statement and means your critical factor didn't reject it.
If a morbidly obese person says to himself, “I'm slim, trim health and happy”, he’d probably feel a little uncomfortable with that affirmation. In this case, because the critical factor knows it’s not true, the information is rejected. It doesn't matter how many times he says it to himself, it’s not going to stick any-time soon. How many times would you have to tell yourself that the sky is green before it you’d believe it?
It would take a lot of work and a lot of time for that affirmation to get through the critical factor to become a subconscious fact. Of course, the subconscious is like an organic computer and so once it is a subconscious fact, it’s just a matter of time before the subconscious mind turns that information into reality. It’s just a matter of time before the person is slim, trim, healthy and happy.
Now there are some short cuts. It’s useful to know that the conscious mind is a very focussed mind and as such can only be in one place at a time. You can only focus on one thing at a time. If you give yourself affirmations and at the same time distract your conscious mind, the chances of these suggestions going through to the subconscious are greatly improved.
For example, if you repeated the affirmation “I'm slim, trim, healthy and happy” to yourself while tapping away at different parts of your face and forehead, your conscious mind would probably be too busy with the tapping to reject all of the affirmations (critical factor bypass). Of course this method would be far faster than just using affirmation alone, but becomes far more powerful with repetition.
This method may also sound a lot like “Emotional Freedom Technique” and having studied hypnosis since childhood, I'm sure it’s no different. There are other methods one can employ to bypass the critical factor too, but by far the most effective I know of is hypnosis. You can achieve a far superior degree of critical factor bypass with hypnosis and this allows information that you consider “reasonable and pleasing” to flow easily into the subconscious mind at a greatly increased rate.
To demonstrate how well hypnosis can work for you, enjoy the Ormond McGill clip below. It’s shorter than ten minutes and very informative. Bear in mind while watching, the client will only accept suggestions deemed “reasonable and pleasing”.