The banana, which has been a staple for thousands of years, is a nearly ideal food, and the British have made it their favourite fruit. The banana has a great deal to offer nutritionally. Because bananas contain less water than most other fruits, their carbohydrate content, by weight, is higher, which is one of the reasons that bananas are a favourite of endurance athletes. Bananas can be easily digested by virtually everyone, including infants and the elderly. This fruit also supplies a substantial amount of potassium along with significant amounts of vitamin B6. Bananas also have a small amount of folate (folic acid) and vitamin C.

The taste and texture of a banana is directly related to its stage of ripeness. The carbohydrates in green bananas are primarily starches that turn to sugar as the fruits ripen. Very green bananas are hard and have an astringent taste, whereas fully ripened yellow bananas are soft, sweet, and creamy. Bananas that are yellow and flecked with just a few brown spots will be at their peak flavour, but their texture is on the verge of being mushy, so many people prefer bananas that have unspotted yellow skins and green tips. There's no harm in eating a less than ripe banana, except that if it is very green, it may be harder to digest.

Choose bananas according to how and when you'll eat them. If you prefer fully ripe bananas, and the shop carries only greenish ones, you'll need to shop several days in advance of the time you plan to eat the fruit. If you prefer bananas just yellow, a day or two will suffice to ripen greenish ones.

Bananas should be plump, firm, and brightly coloured. Look for unblemished fruit: Occasional brown spots on the skin are normal, but sunken, moist-looking dark areas will likely show up as bruises on the fruit. Bananas should have their stem ends and skins intact: A split skin or stem may become an entry point for contamination. There's no quality difference between small and large fruit, so you can choose the "portion size" you prefer. Bananas bruise easily, so handle them with care.

Bananas that require further ripening should be left at room temperature, but away from heat or direct sun. To speed ripening, place them in a loosely closed paper bag. Putting an apple in the bag will further speed the process. Once ripened to your liking, bananas can be held at room temperature for a day or two. Then, you can store them in the refrigerator to slow down ripening; although the skins will turn dark, the fruits will remain perfectly edible. You can keep refrigerated bananas for up to two weeks. But never refrigerate unripe bananas: The exposure to cold interrupts their ripening cycle, and it will not resume even if the fruits are returned to room temperature.