Eating an apple a day may or may not “keep the doctor away,” but this fruit certainly contains more calories and energy potential than a cup of black coffee.Apples are rich in fructose sugar and coffee is rich in caffeine, which is like comparing “apples to oranges,” to use another old expression. Caffeine stimulates your brain and fights drowsiness, but it’s not actually a source of energy.Apples are a great source of many nutrients such as soluble fibre, vitamin C and antioxidants called polyphenols.Apples are also rich in fructose, which is the predominant sugar found in fruit. Fructose takes a little more time than sucrose to be metabolised into glucose, so it’s a good energy source that doesn’t spike blood sugar levels and insulin release too dramatically.A small apple weighing 200 grams contains about 20 grams of sugar and provides a total of 100 calories. Furthermore, the soluble fibre in apples will make you feel full for longer and help keep hunger pains at bay.