A super-fit grandmother has revealed how she maintains her age-defying aesthetic – including a face that could pass for 30 years her junior.

Eva Birath, 70, has put her unusually youthful look down to a strict weight lifting routine – as well as a diet that is free from any plant-based food. 

The grandmother-of-three, from Gothenburg in Sweden, says she lifts weights a startling four times a week, often taking her grandchildren to the gym.

Her extreme diet includes eating some 800g of meat – the equivalent of roughly four sirloins – a day. 

Ms Birath has always been a fitness fan; a keen volleyball player from the age of 12, and competitor in bodybuilding competitions in her 40s, 50s and even 60s.

Other health habits she swears by include regular saunas and cold plunges. 

'I'm just trying to be as fit as I can. I have always prioritised fitness,' said Ms Birath.

'I haven't changed my approach because I'm older. I've just realised it's actually more important as we age.

'I don't eat anything from plants, only food from animals. I think 80 per cent of good health is what we eat.' 

Asked how her current fitness compares with that of other people her age, she said most older adults are 'unhealthy and weak'.

Experts have previously warned against meat-heavy eating regimes – known widely as 'carnivore' diets.

Doctors have blamed the popularity of the eating plan on a subsequent rise in gout – a painful form of arthritis caused by a build-up of uric acid, which is triggered by compounds in red meat. 

Cardiologists have also flagged heart risks associated with such a diet, which is typically high in saturated fat.

Last year, US heart doctor Dmitry Yaranov linked a string of heart attacks in his young patients to meat-heavy diets. 

'The body outside looks like a machine. But the inside tells a different story,' he said.

According to the British Heart Foundation, 'extreme diets high in saturated fat and low in fibre are known to raise cholesterol levels, increasing the risk of heart attack and stroke'.

Eating large quantities of red meat across a lifetime – and few carbohydrates and fruits and vegetables – has been linked to a significantly increased risk of deadly bowel cancer.

Ms Birath revealed that she was diagnosed with colon cancer aged 61, and underwent surgery to remove the tumour.

She was then in her sixth year of following the carnivore diet. 

Ms Birath said of the aftermath of her cancer: 'I'm weaker and my stamina is not as good.'

However, she refuses to use that as a reason to stop and is now passing her love of exercise to another generation.

She credits her lifestyle for how she feels but says there is no overnight trick behind her physique.

Ms Birath's 'secret,' she said, is simply: 'Consistency and only good nutrition.'

The World Health Organisation says adequacy, balance, moderation and diversity should underpin a healthy diet, while European cancer-prevention guidance recommends making whole grains, vegetables, legumes and fruit a major part of daily food intake and limiting red meat.