Jan 15, A medium-sized banana has about calories and only grams of fat; Bananas do contain 14 grams of sugar, but that comes with a healthy. But lately, some of that advice has been questioned—particularly the advice on fruit. A lot of our favorites, including grapes and bananas, are high in sugar. Jan 17, Are you or your loved ones banana fans? It's easy to love bananas: They are self- enclosed, completely biodegradable travel snacks and tasty.