to beat global warming, you have to go veggie, claims paul mccartney. but how easy is it to be meat-free? Kate Smith decided to avoid all animal food products for a month to find out

RECENTLY it dawned on me that for years I have been sleepwalking towards rampant carnivorism. These days I consume meat at every meal. Taking into account my consumption of dairy foods, as well as animal fats hidden in sweets and crisps, it  occurs to me that I am now devouring more animal products than Desperate Dan in his cow pies. Shocked, I determine to eat more healthily and sustainably. With a dietary history that includes spells of failed vegetarianism, I decide to cut out meat, and challenge myself to become a vegan for one month.

Week one During the family shop, I drop a Quorn lasagne-for-one into the trolley. At £3 per meal it's not a sustainable food strategy, but the upside is that after consuming it, I am surprised to realise that I haven't missed the meat. Then I notice that eggs and milk are listed among the product's ingredients. Rats. Failed already. I need some advice.

"We live in a non-vegan world," says the Vegan Society's Amanda Baker, who explains that veganism isn't just about diet: it's a philosophy of life, which involves shunning non-food products such as leather, pearls, wool and silk. She sends me a pack and offers me "going vegan" buddies whom I can contact if ever I feel the need to rip open a packet of ham. I also buy vegan supplements to help with the lack of vitamin B in vegan diets: hopefully it will help prevent the dizzy spells I experienced in previous vegetarian episodes.

It occurs to me that you have to be quite organised to be vegan, and it's probably easier if you live on your own rather than with a carnivorous partner and kids. At first, I try to eat what I normally would, but adapted to vegan ideals - so no meat stock in soup. The food tastes pretty bland, but moving to the recipes supplied by the Vegan Society means much tastier dishes.

Week Two I'm quite enjoying the food and my energy levels have improved. I find it easier to taste individual items, so perhaps my palate is coming out of shock. I do notice, though, that I'm spending a lot more time than usual thinking about food. There's a lot of preparation involved: overnight soaking of mung beans and checking ingredient lists on prepared meals for any sneaky animal ingredients. Eating out is much easier than eating in. Asking for vegan suggestions in restaurants is straightforward. Fast food joints are a different matter.

Thinking about the bigger picture helps me avoid lapses. I remember the lambs I saw gambolling in the field on a recent hill walk, and think about cute baby chicks. Reconnecting the food on your plate with the place where it came from definitely helps.

Week three I have discovered my Achilles heel. Eggs. The main thrust of my animal-empathy approach doesn't work with eggs. And vegan pasta just doesn't taste the same. Nor do cakes. Guiltily, I gobble an egg mayonnaise sandwich on the train. Soon I am indulging in meals involving real pasta. The signs are clear. I am falling off the lentil wagon. For support I call my friend Trish, who became vegan eight years ago after suffering breast cancer. "By living a vegan life, I actively choose to help my health and bolster my immune system," she says.

Week four I have lost about 8lbs in weight, my eyes and skin look brighter and I can't stand the smell of animal fat cooking. But I am struggling with variety, and the time between the egg pasta lapses is getting shorter. After a busy week, I am also struggling with the fact that - since I have decided not to include the children in my experiment - dinnertimes involve cooking one set of meals for the rest of the family and another for me. I have turned into a deranged, frenetic Nigella Lawson, only without the smouldering looks or the repertoire of recipes and well-stocked pantry. The fact I don't have time for two lots of shopping also means I often find myself eating boring meals consisting of broccoli and rice.

Preparing meat for the family is beginning to seem repellent. I now see it as animal flesh and it makes my stomach turn.

THE RESULT At the end of my month as a vegan, I'm glad I tried it. I thought it would be all about sacrifice, but actually it was about recalibrating what I was consuming, getting some balance back. I do occasionally eat meat now, but only if it's organic and produced locally. I can't stand the taste of ham, bacon or any reconstituted meat. I continue to read the labels on products. I see myself as the gatekeeper for my children's health and am conscious that before my experiment, we might have been eating any old rubbish. Now, I avoid supermarkets and buy seasonal produce from local shops.

There have been benefits for my children, who were very curious about what I was doing and why. My 13-year-old daughter Daisy and I had some good discussions about food, and she connected it with lessons in school about food and water scarcity across the world. She already knew that what we eat and consume is connected with what the rest of the world eats and consumes. Our discussions continue. But perhaps the biggest lesson is about compassion, and the need to get some humanity back into how we treat the animals that provide the food on our plates.