Joanna Lumley's figure has remained practically the same since her Absolutely Fabulous days, but the 68-year-old caused quite a stir when she revealed her eating habits.
Speaking to the Mail on Sunday, she said: "‘I don’t eat any meals. I eat a bit throughout the day if I’m hungry, but not a big meal. I’ll have some nuts or maybe some crisps and that’s enough."
Lumley credits vegetarianism with maintaining her figure, and doesn't do any exercise. She added: "‘I don’t go to gyms, but I do rush about. I do stuff with vigour, such as housework, gardening and going up the stairs two at a time.
"I’m full of energy and never ill, and I haven’t eaten meat for 40 years. It’s no coincidence."
So how does Lumley's diet measure up in the real world? We spoke to several nutritionists and dieticians for their opinion.
Alice Mackintosh at The Food Doctor says: "While there may well be benefits to not eating large meals and instead opting for five smaller ‘snacks’ over the day, it is important to do this with caution.
"Snack foods can often seem as though they may be healthy when in fact they may not deliver sufficient levels of essential nutrients from fresh colourful fruits and veg, as well as protein, healthy fats or complex carbohydrates. Though Joanna isn’t eating sugar, regularly snacking on crisps is a far cry from a balanced and healthy diet and many may find that relying on easy convenience foods like this can cause energy levels to dwindle, immunity to become suppressed and concentration to waver."
Small meals, says Mackintosh may help encourage weight loss but they have to contain substance.
Dietitian and BDA spokesperson Priya Tew agrees. "Nuts are good but they won't provide all the nutrients she needs. Fruit and vegetables are great additions because they contain lots of antioxidants which we know reduce the risk of disease."
Calcium in a diet is also good for maintaining strong bones, she adds.
Top nutritionist Libby Limon delved into why Lumley may have arrived at such a diet.
“As we get older our metabolism slows so you don’t need as many calories, however, maintaining a nutrient dense diet is important for optimal health. Everyone is different so some people prefer to eat smaller ‘snacky meals’ throughout the day while others work better on two or three main meals.
"As long as these meals are balanced including lean quality protein, healthy fats, complex carbohydrates to maintain a energy via balanced blood sugar, as well as plenty vegetables for vitamins, minerals and antioxidants, it is what works best for you. Often a side effect of age is low stomach acid, so smaller meals often can be easier to digest."
Nutritionist Karen Poole agrees with Lumley's approach to exercise. "I do agree with the fact that you don't have to be a gym member to exercise properly as walking , gardening and cleaning can all provide a good workout you just need to put your back into it.
As for her diet, she adds: "Some people are driven not by a desire to be healthy but to be thin and will survive on very little and feel they function pretty well as that is how they are used to performing.
"I would find it hard to believe that such a nutritionally sparse intake would be acceptable, enjoyable or doable and I know I would suffer with energy and concentration levels over the course of the day and restful sleep at night. It is not advice I would offer to any client."
Lumley will be starring in a Comic Relief version of The Great British Bake Off despite saying: "I hate cake".