Story highlights A medium-sized banana has about 105 calories and only 0.5 grams of fat

Bananas do contain 14 grams of sugar, but that comes with a healthy dose of fiber

Bananas also offer potassium, magnesium and vitamin B6

Paignton Zoo in Devon, England, isn't monkeying around with their animals' diets anymore. Zookeepers are trading the monkeys' favorite fruit in for green leafy vegetables, saying bananas grown for human consumption are full of sugar and calories.

"Wait, even the fruit isn't healthy anymore? What's left?!?!" CNN reader NeoPrudentist posted in what was soon rated the No. 1 comment on the story.

What's left, indeed. First coffee . Then salmon . Now this?

Not to worry -- this isn't a case of human see, human do. Despite sharing more than 90% of our DNA with these fuzzy primates, humans have some very distinct differences in anatomy.

Those English zookeepers aren't totally wrong. All fruit contains sugar, and bananas are slightly denser calorie-wise than other types of fruit. But when it comes to nutritional bang for your buck, bananas are hard to beat. Just remember -- no monkey business: Eat 'em in moderation.

Sugar

Bananas contain about 14 grams of sugar.

You may have heard that sugar from fruit is better than the sugar you find in candy. But sugar has the same molecular structure whether it comes from a kiwi or a cupcake.

Both contain fructose and glucose, although in varying proportions. Neither kind of sugar is really better or worse for you, experts say; the body just processes them differently. Fructose is broken down in your liver, while glucose starts to break down in your stomach and needs insulin to be fully metabolized.

The good thing about fruit is that the sugar often comes with fiber, which slows digestion and gives the body time to use it as fuel instead of storing it as fat.

Speaking of fiber...

Bananas have about 3.1 grams of fiber.

Unripe bananas are slightly better for you than ripe bananas, experts say. Greener bananas contain what's called resistant starch , a type of fiber that your body has trouble absorbing. Studies show resistant starch fills you up and may even help you burn fat.

Unripe bananas score 30 out of 100 on the glycemic index ; ripe ones score about 50. The index indicates how quickly a carbohydrate increases your blood sugar levels. Low-GI foods may help you lose weight because they help control appetite and delay hunger, according to the University of Sydney.

Power boost!

Every long-distance runner knows the power of a good banana. The fruit contains high levels of potassium and magnesium -- two nutrients athletes lose when they sweat.

Bananas also have a chemical property that may help control stomach pain and reduce your risk of diarrhea or constipation, according to LiveStrong.com