Knowing what you should eat won't automatically cure you of bad food habits. Our attitude to food is as much about emotion as it is about satisfying hunger.

Throughout my battle with depression I have tried many approaches - one of the more effective for me being Cognitive Behavioural Therapy. This involves retraining your brain to avoid patterns of negative thinking, replacing them with new more positive neural pathways.

All the therapeutic techniques I had learnt were as relevant to the dinner table as any other aspect of life which CBT helped. Instead of allowing a rush of emotion to drive me towards comfort food, I tried to stop and judge instead what my body,or more particularly my brain, needed. It deserved better. It might be as simple as getting a boost from somewhere else rather than from a pudding.

I was interested to read about the experience of the tennis player Monica Seles, who battled with binge-eating for ten years but was cured when she began to focus on food properly for the first time. 'Every time I sat down to a meal, I could make a decision,' Seles writes. 'Was I going to treat myself with love and respect, or was I going to sabotage my own happiness and health for a short-term rush. The decision was an easy one: I chose nourishment over destruction every time. Eating wholesome food left me satisfied much more quickly than mounds of processed fake food ever did.'

The other psychological shift is to move from feeling deprived to feeling you are gaining something extra. It is not about suppressing all pleasure in food. I tried not to focus on what I couldn't eat but on all the delicious dishes I could enjoy: what I could add rather than what I had to take away literally .

Seles writes of how important it was for her not to feel she was on a 'diet'. As she rightly says, that implies there is a danger you could fail to keep to your diet. And nothing is more tempting than something that is forbidden.

Breaking bad food habits slowly

I found the easiest approach was to adapt slowly, rather than to enforce wholesale change overnight. I might have a cooked breakfast, but will have tomatoes alongside the bacon. I haven't abandoned salad dressings, but I do use different oils: wheat germ or flax, sesame or sunflower oil, as well as the more usual olive oil. I add almonds, pecans, cashews, walnuts and pine nuts to salads.

Once you start to eat well, the process gets easier. You begin to feel better. By taking charge of your life, you enter a virtuous circle of looking after yourself. One of the most terrifying feelings about being depressed is the utter lack of control; you feel like a piece of flotsam, blown by icy winds to terrifying places.

Gradually I became more attuned to the connections between mood and food. The science was there to be experienced if I stopped to think about it; the sugar-rush I felt after those refined carbohydrates and the crash in mood that followed; the steady and calming effect of an oatcake mid-morning; how much more effective my day would be if I ate a good breakfast; how much better I would sleep after a bowl of porridge at night.

As I found I was able to achieve more, I realised I couldn't afford not to eat well. I had commitments I wouldn't be able to fulfil if I stopped being properly nourished.

Rachel Kelly is the author of Black Rainbow: How Words Healed Me - My Journey Through Depression