NHS surgeon and social media sensation Dr Karan Rajan has dished out a fascinating insight into bananas on TikTok, highlighting how each ‘stage’ of the fruit offers distinct health perks. Dr Karan delved into the details, saying: “Stage one: the under-ripe green warrior. A resistance starch powerhouse, acts like a prebiotic to feed you gut bacteria and leaves your microbiome happier.
“It’s low in sugar, only ten grams per hundred grams compared to 17 grams per hundred in an overripe banana. Useful if you’re keeping a close eye on this. It’s also got three and a half grams of fibre per hundred grams. Ideal for diabetics controlling blood sugar fluctuations and general gut health.”
Prebiotics, important plant fibres found in foods like garlic, onions, and asparagus, nourish beneficial gut microbes, fostering better digestion and immunity. Harvard Medical School says they even aid dietary calcium absorption, enhance glucose regulation, boost immune functionality, and may cut colorectal cancer risks.
High in these gut-friendly fibres, whole grains and certain fruits and veggies, including bananas, make top-notch prebiotic choices, reports Surrey Live. At the ‘barely ripe’ stage of a banana’s development, Dr Karan hailed it as a “balanced king”, noting its high fibre content – around two and a half grams per hundred grams.
With a sweeter taste yet low sugar levels, these bananas offer not only a smidgen of potassium but also benefits for gut health without overwhelming sweetness. He explained: “You also get a little potassium boost as more of it becomes bioavailable due to decreases in fibre and starch. Perfect for those who fear commitment but want a bit of gut health and some sweetness.”
Upon reaching full ripeness, bananas turn a vibrant yellow and are brimming with antioxidants like dopamine, catechins, flavonoids, and amines. Dr Karan explained: “More catechins equals better for heart health and inflammation. Compared to the other stages, it’s also got higher vitamin C and B5 levels.”
These fully ripe fruits, easier to digest due to their simple sugar contents, provide quicker energy release and are ideal pre-exercise snacks or sweet fixes for the patient. The doctor continued: “It’s easy to digest because most of that resistant starch is now converted to simple sugars, so you get faster energy absorption. Perfect as a pre-workout fuel, sweet cravings, and anyone who finally gives up on waiting.”

When bananas advance to the fourth stage, known as “overripe sweet chaos”, they pack approximately 17 grams of sugar per hundred grams. This makes them an excellent source for a rapid blood sugar spike according to Dr Karan.
This is ideal for those in need of a quick energy boost. Dr Karan stated: “This stage is the richest in antioxidants. Those dark spots, that’s a marker of high catechin levels, the same stuff found in green tea. Perfect for a banana bread redemption arc, smoothies, natural sweeteners, and for accepting that time is relentless.”