Some people prefer their bananas yellow with a tinge of green, while others prefer the sugary sweetness of a banana that has brown spots on the peel.

But it's not just the flavour that's different, for there are distinctive effects on your body and health dependent on the ripeness …

Unripe, green bananas have been shown to have 20 times as much resistant starch as ripe bananas.

This is a form of starch which the body struggles to break down (it 'resists' the digestive process), so it passes straight through the gut.

This slows down the speed at which the carbohydrates in the fruit are converted into glucose and absorbed into the blood.

A green banana typically has a glycaemic index (GI) of 30, compared to 58 for a ripe banana.

Not only is resistant starch good for steadying your blood sugar levels, but 'good' bacteria in the colon also feed on it.

They, in turn, boost the digestive enzymes that help us digest carbs and absorb vitamins from food, as well as protect us against any unfriendly microorganisms.

Professor Gordon Carlson, a consultant gastric surgeon at Salford Royal NHS Foundation Trust, told Good Health he eats one relatively unripe banana every day to boost his gut health. The benefits of green bananas were confirmed in a major review of 18 studies on their nutrition, published in the journal Nutrients in 2019.