I'm an obesity doctor, the secret to longevity is not just about how big you are

A leading doctor claims that obesity isn't as big of a health issue as people have been led to believe.

Appearing on the Diary of CEO podcast, Dr Gabrielle Lyon said that the biggest thing people need to focus on now is their skeletal muscle.

'Everybody focuses on obesity, but obesity is not our problem,' she told host Steven Bartlett.

'If you are in the lower one-third of strength, you have a 50% greater risk of dying from nearly anything. You have to prioritise skeletal muscle.'

Skeletal muscle makes up almost 40% of a body's total mass and is responsible for movement, metabolism, energy, the storing of nutrients and more.

'This is the organ of longevity, the only organ system that you have voluntary control over,' Dr Lyon shared.

'Your skeletal muscle is your primary site for glucose metabolism and fatty acid metabolism. It is your body armour,' she continued.

'Those that are in the lower one-third for strength, you have a 50% greater risk of dying from nearly anything.'

To combat this, Dr Lyon said that resistance training with weights is key to good health and longevity.

If you don't, not only are you at risk of physical effects like mobility issues, you're also risking a loss of brain functionality.

'The majority of dementia is Alzheimer's dementia, which plays a role in metabolic regulation - type three diabetes of the brain,' she said.

'If your skeletal muscle is unhealthy, you are likely having not only skeletal muscle insulin resistance but brain insulin resistance... You cannot be sedentary and be healthy.'

Research has recently suggested that weightlifting is important for most adults, including the elderly.

Resistance training was found to have strength benefits that lasted years into retirement.

People naturally lose muscle function as they get older with faltering grip and leg strength viewed as a strong predictor of death in elderly people.

Resistance training, which can involve weights, body weight or resistance bands, has been shown to help prevent this from happening.