Food, Cigarettes, and enjoyment

I'm in the middle (or at least the start of the middle, which is still the middle but could still be considered the beginning) of a healthy eating fortnight. No special diet. Nothing too hard. Just plain old trying to eat some healthy foods rather than the shit I usually eat. The reason? An experiment into the effects of food on the mind. An attempt to reinvigorate the mind if you will. The nutritional value of the things I generally live on is like zero so I'm interested in what the effects of eating things with like all the good stuff happening will be.
Results so far? Here's the problem. How to separate the actual effects of the food from the effect that me thinking the foods are having will have - the psychosomatic effect if you will. So yeah, I actually feel quite good - not feeling as tired as I generally do, have a bit more energy generally - hence me writing this and I've been getting another bit of work done that I hardly ever get round to, despite the best of intentions - and, here's the actual reason that I suspect the psychosomatic outweighs the physical benefits: I feel happier.
Happiness comes from task completed, the sense of satisfaction at success, in this case the continued healthiness of the food I consume. It's like stopping smoking. Whenever I stop, after a couple of days I always get into a state of mind where the addictive quality of the cigarette is competing with the addictive quality of the feeling of needing a cigarette - the edge that comes with needing a cigarette continuously becomes addictive in itself - and if I can go without a cigarette for another couple of weeks it takes over completely (not quite completely, for obviously I start again at some point - but even here the sweetness of nicotine is tempered by the dismay at the loss of the edge).
With the food it is slightly different: I have no emotional investment in food. I eat crap, not because of any enjoyment I get, but simply because it is convenient - I feel aggrieved at the time it takes to prepare meals, time that could be spent more constructively (or even less constructively, but more enjoyably). Whereas cigarettes are in the register of enjoyment, and thus the satisfaction I get from either smoking or not smoking is higher than the satisfaction I get from this healthy eating diet.

It has occurred to me that I had the idea of this healthy eating kick on Monday an hour or so after I had a cigarette after an attempt at stopping. It is as if one failure led to the a desire for a task I could complete...