What made you decide you wanted to lose weight?

The weight had been creeping on for a long time. I'd tried to ignore it, but I was conning myself. It just got worse and I started to lose sight of exactly how much weight I'd gained. I was medically obese.

I've never been as fat as I was when I started this diet and it was only when I began to shift the weight that I realised how miserable it had made me.

I also wanted to be a good role model for my daughter Maddie who was born on Christmas Day in 2002.

I don't want her to have any food obsessions because she could see me eating badly and jumping on and off scales.

Did having a baby make you gain weight?

Putting on weight was nothing to do with actually having the baby, but it was partly to do with the breast-feeding.

It made me so depressed that I just kept eating biscuits and bread and the weight piled on.I was actually the happiest I've ever been with my body when I was pregnant.

I lost over 1st because I wasn't drinking and I wasn't eating any rubbish because I wanted a healthy baby.

Which parts of your body did you least like?

All of it, to be honest! I had a triple chin and my eyes had gone piggy because of all the fat around them.

I'd learnt only to look at myself in mirrors at certain angles. I deliberately wasn't looking at my body any more and seeing myself on TV was making me depressed.

I had to stop watching myself in the end, it was so hideous.

What was your diet like before?

I did the classic thing of not eating any meals because I was fat, but that meant I was just grazing all day long on rubbish.

I'd deliberately cook Maddie too much so I had to eat the leftovers. I'd cook a roast dinner for my husband Mark but not eat any, then end up dipping bread in the gravy. I'd get a curry and not have rice, then I'd order Mark a naan bread he didn't want so I'd have to eat it.

Which diets had you tried?

You name it, I've done it. Atkins, cabbage soup, the grapefruit and boiled egg diet, the egg and bacon diet, the fruit diet and Rosemary Conley.

I can't do low-fat diets because they drive me insane. Not having fat in your diet can cause depression – you're thin but you feel like crap.

This was the first time I'd exercised as well – and it does make a difference.

Did you follow a particular diet?

Anita Bean, who co-wrote Carol Vorderman's detox books, helped me come up with an eating plan. It was brilliant because she looked at the psychology of my eating as well as what I should and shouldn't eat.

I didn't want to restrict how much I could have because I knew I'd end up obsessing about the next meal. We also agreed that I should sit down to eat every meal.

We never discussed what weight I was and how much I wanted to lose – we just took the idea that I needed to eat more healthily. If I lost any weight, that was a bonus.

What food sacrifices did you make?

I cut out caffeine completely and cut right down on alcohol. I banned bread and crisps from the house for the first month and cut out all meat.

I had to film in Spain on the third week of my diet, so I introduced grilled fish and chicken, but I'd make sure I had it with a salad.

I drank at least 3ltrs of water a day and only snacked on nuts and fruit. I'd eat a lot of brown rice, which is surprisingly tasty if you cook it properly, and I made myself vegetable soups and steamed vegetables. I'd have at least three or four small handfuls of nuts a day, which I chewed well.

I mainly ate organic foods – processed food was banned from my diet.

I was eating three full meals a day, more than I'd eaten for months. I wasn't hungry, I had loads of energy and I was losing weight. I lost 9lb in the first week.

What was your first visit to the gym like?

Horrendous. Before I went I tried on loads of gym gear and asked my mum how I looked and she said: 'You look the fattest you've ever been,' which, sadly, was true. It was embarrassing. I was bloated, grey-skinned and there were mirrors everywhere.

All through the session I thought: 'I'll get through this, then I'm never coming back.' Then something happened in the last 10 minutes and I actually felt good.

Anyone who feels unfit will think like I did: 'It's going to take me so long to get any fitter that I can't be bothered.' But within five sessions I was doing things I couldn't have done in the first session and my fitness level improved really quickly.

What was your exercise regime?

I went to the gym regularly and had two fantastic fitness instructors. They made me realise that when I'd gone to the gym before it had been a complete waste of time. Every time I'd got anywhere near breaking a sweat I'd given up.

I was doing mainly fat-burning exercises. I spent a lot of time on the cross-trainer and did a lot of fast walking.I refused to run. If you've got big boobs that's the most embarrassing thing in the world.

If I wasn't at the gym I'd make sure I took the stairs instead of the lift and I'd take Maddie out for loads of walks in her pushchair, wearing weights around my ankles. The best exercise ever was attaching the weights to my ankles and bending and lifting my legs. I lost an inch around each thigh doing that every day for a month.

Were there any moments when you felt like giving up?

I had some slip-ups – who doesn't? – but I always made sure I was good the following day to make up for it.

The worst thing was when I was filming in Spain and I was stuck eating nuts while all the rest of the crew were eating chocolate and custard croissants.

I spent the whole time drooling over them but resisting. But on the last day I finally gave in and had one. The irritating thing was that after all that it tasted disgusting. I had a McDonald's then to make up for it and it was my first bread in weeks. It was gorgeous, but I did feel bad.

Which areas of your body are you most pleased with?

My face is a lot thinner now and I've finally got my waist back after thinking it was lost forever. There's no area that's better than any other.

And I'm really pleased with how much more energy I have now.

When did you first notice your weight loss?

The big shock came when I started filming City Hospital again. I started the diet just after the last series, so they hadn't seen me since. Everyone was amazed that I'd shrunk so much.

The biggest buzz I had was when two girls walked past and, when they thought they were out of earshot, one turned to the other and said: 'Was that Nadia Sawalha? I almost didn't recognise her. She's lost loads of weight.' I had to stop myself from chasing after her and kissing her!

Has it made a difference to your wardrobe?

It was a big thing for me to get jeans on as I hadn't worn a pair in three or four years.

I especially wanted to be able to fit into a pair of Diesel jeans that I'd bought ages ago– but I thought that was just an impossible dream.

I was clearing out a cupboard upstairs and found all these old trousers that I hadn't been able to get into for years. I was about to throw them out when my sister Dina demanded I try them on. I thought there wasn't a chance, but one by one they all fitted – and some of them were quite baggy!

I bought a lovely dress from Karen Millen too. But it's a size 14 – and it's far too big!

What difference has the weight loss made to your life?

I'm far more confident and a lot happier. I can't believe how depressed I was about it. You don't realise how down you are until you come back up.

I can really run around with Maddie now and she loves it. It's affected everything. I even have the energy to get down on my hands and knees and wash the kitchen floor sometimes now!

Will you stick to this diet?

I'm definitely going to keep going with this. I've lost over 2st in three months, so there's no reason why I can't lose more. To be honest, it's hard work, but once you see the results it's well worth it.

I hate those people who say that it's easy to lose weight, but my skin, my hair and my eyes are all looking better and my body is working efficiently for once. I want to lose 10 more pounds – but at the moment I'm just happy to see my waist again.

My stomach isn't as flat as a pancake and it never will be, but I can hold it in a lot better now. I'm never going to be skinny and I don't want to be because I'd have a complete change of personality.

What advice can you give to readers?

If I can do it, anyone can. I've been the laziest most undisciplined woman in the world. I really thought I wouldn't be able to lose the weight. I thought I'd got to a certain age, had a baby- and that was it. But now I can see the body that I used to have coming through. It's not just about being slim, it's about being healthy. If you really want that enough, you can definitely get there.

Nadia's Top Tips

Drink a glass of hot water and lemon when you get up in the morning because it clears out your system and slightly speeds up your metabolism. It may not sound appealing, but by the fifth day I was actually looking forward to it.

If you know you shouldn't be eating it, don't have it in the house. Crisps were banished from mine.

If you think you're hungry drink a glass of water. If you're still hungry five minutes later, eat something then. The signs for thirst and hunger are very similar.

If you need a sugar pick-me-up, eat a small handful of nuts and raisins to satisfy the craving.

Eat till you're satisfied – not until you feel stuffed. It took me a long time to work out the difference between the two.

Get a trainer at the gym, even if it's only for a couple of sessions. They'll show you which exercises will work for you and make sure you're making the most of your time there. Even if you can't afford a full session with one, trainers are always around to give you advice.

Go for walks with ankle weights on. It's not that much harder and you don't have to go to the gym.

Don't stop exercising just because it begins to be hard work. Those extra five sit-ups you do after you start feeling the strain are actually the ones that burn off the fat.

Don't be too strict with yourself. If you really want that piece of chocolate, have it and be extra-good the next day. But before you eat it, think again if you really need it.

Always sit down to eat your food. If you make sure you eat at a table every time, you're far less likely to snack.

Nadia's Typical Diet Before

Breakfast

Three big cups of milky tea

Mid-Morning

Half an egg mayonnaise sandwich and a bag of crisps

Lunch

Crisp sandwich

Mid-Afternoon

Cheese on toast

Late Afternoon

Maddie's left over fish fingers and a chocolate trifle

Dinner

Small portion of spaghetti bolognese

Evening

Bowl of cereal. Several large vodka and tonics

Nadia's Typical Diet After

Breakfast

Freshly made apple and carrot juice. A bowl of oats with apricot sultanas and nuts (two walnuts, two pecan nuts, two Brazil nuts chopped). Nadia didn't like soya milk, so exchanged for water or juice

Mid-Morning

A palmful of cashew nuts or almonds

Lunch

Homemade vegetable soup with guacamole or hummus

Mid-Afternoon

A palmful of cashew nuts or almonds

Dinner

Brown rice boiled in vegetable stock with fried onions, celery and garlic added to it, steamed vegetables on top, olive oil drizzled all over and a blob of hummus added on the side.
Karen Dunn