Mary McCartney has plenty to be proud of. There's her acclaimed photographic career and popular cookbooks, and her former Beatle legend dad, and her four sons.

But if all that wasn't enough, Sir Paul McCartney's daughter is also proud to be vegetarian - and even prouder that her pioneering mum Linda started her own veggie food range when such things were unheard of. A quarter of a century later, Linda McCartney Foods (LMF) is a major part of a burgeoning UK vegetarian food market that has almost quadrupled since the range was launched.

FOOD REVOLUTIONARY

Mary, who grew up on the family’s farm in Peasmarsh, near Rye, is rightfully proud of Linda's achievements, and the way she shared her environmentally-friendly ethos with her family and brought vegetarian diets to the wider public.

Since LMF launched in 1991, the number of vegetarians in the UK has doubled, from 6% of the population to 12%.

"She didn't even realise what a food revolutionary she was," says Mary proudly. "Vegetarian food ranges are quite mainstream now, but when she started, it was completely unheard of to have a range like that. I think we're all quite proud of it, and we want to work to ensure it carries on her ethics."

DON'T EAT BAMBI

Along with being a successful photographer and writing vegetarian cookbooks, strong ethics are something else Mary, 46, shares with her mum, who died from breast cancer in 1998.

She explains that her fundamental reasons for championing a meat-free life are both the animal rights issues, and the environmental damage caused by meat production - the UN says the livestock sector is one of the most significant contributors to serious environmental problems.

"Originally it was because, as a family, we were very conscious of where our food came from - my mum was a great cook and I didn't want to eat animals or have anything killed for me to eat it," she says.

"When you're a little girl you're thinking, 'I'm not going to eat Bambi'.

"The industry and the bad impact on the environment added another element to my strength of feeling. You might think a burger looks good, but can you really eat it knowing how it got to your plate?"

MEAT FREE MONDAY

As part of her determination to further promote meat-free living, Mary started the Meat Free Monday campaign with her father and sister, fashion designer Stella McCartney, in 2009. The campaign encourages people to forgo meat at least one day a week, both to help the environment and improve health - an Oxford University study found that eating meat no more than three times a week could prevent 31,000 deaths from heart disease, 9,000 deaths from cancer and 5,000 deaths from stroke.

And it seems the campaign is striking a chord with the British public, as research shows 59% of Brits want to reduce their meat intake, with the majority citing health reasons as their greatest motivation.

NOT NECESSARILY HEALTHY

While Mary agrees that being vegetarian can be a healthy option, she's aware that meat-free doesn't necessarily equate to healthy - chocolate, saturated fats and alcohol can all be consumed by vegetarians, after all.

She says she's not worried about her own health because she feels good and knows she eats a balanced diet, but also stresses that vegetarians, just like meat-eaters, need to be aware of what they're putting into their bodies.

"Sometimes people say they were vegetarian, but then they got really ill and their doctor told them they had to start eating meat," she says.

"But were they eating properly, or were they just eating salads and bread? You're responsible for eating what's good for you, and you've got to get a balance or you'll be lacking in vitamins and minerals.

"You need to think, 'What have I eaten today that'll give me the things I need?'"

SUCCESSFUL RECIPE

That healthy eating ethos is important in the vegetarian recipes she creates, she says, which emanate not from any formal culinary education, but from what she learned from her mum, and her own experience of veggie cooking.

"They're a much more positive way of introducing vegetarianism than scaremongering about the environmental impact," she explains.

"I've become more and more aware of my health throughout the years, and when I put a recipe together, I'll look at it and think, what health benefits am I going to get out of it? And how am I going to make it as satisfying and as tasty as possible?"

LASTING LEGACY

Mary and her family are currently highlighting the 25th anniversary of Linda McCartney Foods, for which they've provided full creative support and ideas since the business was sold in 2000.

She says: "Everybody is very conscious that the food has my mum's name attached to it, so we're very keen to be involved and very passionate about it because we want to carry on what she started."

• For more on Meat Free Monday, visit www.meatfreemondays.com