I was fat and unhappy, so I got fatter and happier

Revelations: Tabitha Wady, actress, london, 1996

MY PARENTS' divorce was the start of my weight problems. I still remember vividly when they split up, though I was only four. I was terribly angry, especially towards my dad. He would often criticise me for eating so many chocolate biscuits. When you're a child that really hurts. He wanted the best for me, but saw only the external part. I always felt a great pressure to be thinner.

I believed it was my duty to be protective towards my mum and younger sister, especially as my mother worked all night as a nurse. So I was horrified when the man who was to become my step-father was introduced. I resented him terribly because he was taking away Mum. I was absolutely revolting. I used to snap "you're not my father". I'd stamp upstairs, slam my bedroom door and play my records loud. While he was terribly patient with me, I was volatile and feisty. By nine, I was worried enough about my weight to join Weight Watchers. It affected me a great deal. My sister was slim, blonde with blue eyes - completely different from me. I was never jealous of her but I desperately wanted to be Madonna, and desired a ra-ra skirt more than anything in the world.

Even at 11, there were girls at school who seemed glamorous and sorted, with boyfriends and horses. I was not particularly gorgeous; I was still overweight and a bit boring, and I desperately wanted to be an actress. I must have seemed a bit odd. Certainly nobody knew how to react to me. Although it was an ordinary, all-girls comprehensive, there was a trend to be anorexic. I was never massive, just a normal teenager, but everybody was into it so I joined in. Terrible though it sounds, there was a phase when I ate only 500 calories a day. I'd have an orange for breakfast, and perhaps an apple for lunch. Obviously I did lose weight, but it went up and down. I remember sitting in my bedroom listening to the Smiths, and one particular track called "Last Night I Dreamt Somebody Loved Me". I thought I'd never have a boyfriend.

I arrived at drama school quite slim and fairly happy with my weight. However, the first six months in London, away from home, were quite miserable. We would have to wear Lycra leggings and a leotard for country dancing - I was forever worrying what everybody would think of my thighs, and listening to the other girls boasting of how they would swallow a mug full of vegetable oil to make themselves sick. It was like a competition - somebody else chipped in that you had to vomit within 20 minutes or it would be too far down. I took the opposite approach. Having a hard time and hating everybody, I ate lots of naughty things and became particularly partial to Marks & Spencer's individual Christmas cakes. I was putting on weight again and became paranoid. Everybody would tell me I was pretty, but needed to be thinner if I wanted to be a lead rather than a character actress. We had a Russian teacher who, as part of my assessment, told me to watch my weight or it could become a problem later. It drove me nuts. He had picked up on my worst fear: it could stop me achieving everything I wanted. I flew home to Bath, devastated, and told my mum. But she thought that maybe he was right. More floods of tears and I was back in my bedroom, listening to the Smiths.

The turning-point came after I invited an agent, who had praised a small part I played in a film, to my end-of-course shows. I'd worked hard, and given as good as I could, but her opinion was: "You're a really good actress, but you could lose some weight. Get down to the gym."

This time, I'd had enough. During my final year, 1996, a lot of the female teachers were more supportive and I started getting better roles. It had been slowly dawning on me: by believing the only way of achieving success was to weigh less, I was lining myself up for trouble and heartache. If this is what my life is going to revolve around, I thought, I'm not going to enjoy it very much. So I decided to be an actress rather than the stereotypical pretty girl. Finally having got my priorities right, I found a different agent. I needed someone who believed in my talent. It was time to come to terms with being me.

Recently I read an article about Jennifer Aniston of Friends, which said that to be an actress you had to be thin - the biggest rubbish I've ever heard. Acting is about transformation: if you want to be play different characters you need to be able to adapt - mentally and physically. I went for an audition for the lead in a feature film as a sumo wrestler. It's about a girl from Yorkshire who hates her body but whose husband thinks she's beautiful and makes her do soft-porn pictures. It is so brilliantly written and inspiring because she learns to believe in herself. I decided I must play it. But they told me: you're a bit thin. Hallelujah! So I agreed to put on weight. I've been eating all sorts of yummy things, and am now a stone and 5lb heavier. There is nothing better to conquer your demons than going all out for something. Other young women, who are being told you have to be stick-thin to be acceptable, will watch this film and see you can be beautiful without living on carrot sticks.

My weight is no longer an issue, partly because I don't put my parents on pedestals any more. I've learnt forgiveness - in the long run the divorce was for the best. These days it is my stepfather or my mum who I go to with my problems, while my dad has become more like a friend. He is still hard to impress; I always feel I have to work so hard to make him proud - which probably isn't true or fair. Will I lose weight after finishing my sumo film? It depends on what happens next. Perhaps I'll play an anorexic supermodel - why not? But I'd have to wear very high heels for that.

Tabitha Wady plays Lydia in `Berkeley Square' on BBC1, on Sunday nights at 8pm

Interview By Andrew G Marshall