A big kitchen table is being laid out with lunchtime goodies. Green bean, tomato and red pepper salad and beetroot-and-chocolate brownies jostle for space among colourful bowls of fresh pineapple and strawberries. Noticeably absent is any sort of meat, butter or cream. But the hungry little group who gather round to eat together don't seem to notice.

Everyone is keen to start following the advice of Kellie Anderson, the health educationalist who specialises in cancer and nutrition at the Maggie's Centre in the grounds of the Victoria hospital in Kirkcaldy. This group of cancer survivors - who are all either living with a cancer diagnosis or have recovered from the disease and want to remain cancer-free - are here to learn the fundamentals of what to eat and how to cook it in order to stay as well as possible.

Diet has a vital, if largely unacknowledged, role to play in cancer management. Apart from helping boost the immune system, build strength and keep weight down, it can also promote mental and physical wellbeing. "Your diet is the one thing you can control when everything else is in the hands of the doctors," says Anderson. "So taking charge of what you eat helps lessen the feeling you're losing your independence - which helps retain self-confidence."

Shirley Paterson, 69, from Burntisland, has a tumour behind her breastbone. Her cancer has returned following treatment for breast cancer five years ago. She is taking chemotherapy in tablet form but suffers from nausea - and her husband of 40 years doesn't cook.

One 35-year-old from Glenrothes has breast cancer and has had four chemo and one radiotherapy treatments. She's now on the last leg of her chemo, and is dismayed to discover she has put on quite a bit of weight. "I used to exercise four to five times a week, but that's all gone to pot," she says. "I don't have the energy to exercise or to cook, so my diet has become poorer." Another woman, who has had three chemotherapy treatments, has succumbed to infections several times. She is here for advice on what to eat during chemo to prevent further attacks.

Sheila Hutton, 57, has had chemo and stem cell treatment following her diagnosis of non-Hodgkins lymphoma; she also has had a mastectomy following a mammogram last year. She, too, has put on weight: "Steroids combined with the menopause have played havoc," she says.

Bill Day, 74, also from Glenrothes, has recently finished a course of "very aggressive" treatment for his non-Hodgkins. His appetite is returning for the first time in years and he and his wife are keen to know what he should be eating at this stage. "I can't help wondering," he says, "if my love of smoked bacon, ham and fish caused my cancer in the first place."

This self-blame, the conviction that we have caused our own cancer by eating the wrong foods, is typical - but in most cases misplaced. "People often feel it was their diet that caused their cancer, but cancer is multi-factorial, in that most don't have one single cause, and there's more involved than diet," says Anderson. "Equally, people often question why a lifetime of eating all the right' things didn't help prevent cancer. But my advice is not to look back. This is all about looking forward, finding ways to stay in control and to do everything you can to promote your own wellbeing."

Nutritional needs during cancer treatment and recovery are increased because the extra stress on the body from cancer itself and from treatments for cancer can affect the body's metabolism of nutrients, especially protein. Because of stress on the immune system, protein is used more rapidly, drawing on muscle stores if an adequate and consistent supply of protein-containing foods is not available.

This can cause tiredness, fatigue and lessened appetite. So protein - meat, eggs, dairy, seeds, nuts and pulses - should be a part of every meal and snack. Combined with carbohydrates and fats, such a diet can help keep the beleaguered body strong. Anderson says: "All the food groups are very important with cancer. Don't skimp on any food groups: spread intake out throughout the day, as they're more effective that way. It's better to look at a variety of foods within each group rather than supersizing or limiting one group. Blueberries and broccoli, for example, are very good for us, but only in the context of a varied diet.

"And not everything is necessarily better for us raw because sometimes the nutrients are released when cooked and when oil is used in cooking."

But the heavy emphasis Anderson places on plant foods is striking. "In addition to containing vitamins and minerals, plant foods are good sources of phytochemicals and antioxidants, biologically active compounds that can help protect cells in the body from damage that can lead to cancer," she explains. "They also contain lots of fibre and, because they are less energy dense, help us maintain a healthy weight."

Studies undertaken by the World Cancer Research Fund UK show that people who eat a lot of red meat tend to eat fewer plant-based foods, so they benefit less from their cancer-protective properties.

Although red meat contains many beneficial nutrients, it recommends eating only 500g (cooked weight) per week. WCRF says that because smoked or cured meats contain more salt, saturated fats and chemical additives, they should be avoided.

Anderson believes the government's daily recommended intake of five portions of fruit and vegetables is way too low, and that it should be increased to 12 portions a day, or more than one-third of the daily diet, to make up the bulk of the diet. Nibbling on fresh pineapple, ginger or peppermint can also help with nausea.

Very often, however, the patient can't face cooking or even food shopping, either because of nausea or fatigue or both. The tastebuds can be affected by treatment, too. So, to cut down on effort, Anderson recommends some quick meals including Lidl's tinned white beans and crayfish in brine, Bird's Eye "Steamfresh" frozen vegetable medley, Tilda microwave brown basmati rice, tinned "Lazy Onions", Ainsley Harriot's flavoured couscous, Tesco's breadcrumbs in a tub. Such meals as stir-fries, bacon and egg salad, crab and courgette pasta or sardine couscous can be prepared by friends and partners. "Remember," says Anderson, "Friends and family want to help you, and asking them to cook or shop for you can let them feel useful."

The most astonishing aspect of the entire Maggie's workshop is that nobody attending had been given specific nutritional advice from their doctor before now - even, as in some cases, after years of treatment. Anderson says: "It's true some people haven't been given nutritional advice. I do feel oncology clinics should be giving more information about what Maggie's can offer cancer patients, and that hospital dieticians could be recommending us for specific problems such as digestion."

Simple steps to a healthier lifestyle