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. However, if you load your coffee with cream and sugar, that’s a different story.
You can get a boost of energy from many sources, including calories, oxygen, stimulants, hormones and a variety of drugs, but not all sources actually add energy to your system. Calories from food are the main source of incoming energy that powers your body, although various vitamins, minerals and other nutrients are needed for healthy function. Sugar from carbohydrates is quickly broken down into glucose, which is absorbed into your bloodstream and transported to all your cells to produce energy. In contrast, stimulants and other drugs excite your brain and body over the short term, but actually end up depleting your energy stores with time.
Apples are great sources of many nutrients such as soluble fiber, 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 metabolized 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. Eating a small apple may not give you a dramatic energy boost, but it will supply a steady supply of glucose to your brain and muscles for at least an hour or so. Furthermore, the soluble fiber in apples will make you feel full for longer and help keep hunger pains at bay.
Black coffee is a rich source of caffeine, but it contains very few calories and none from carbohydrates. Caffeine is a powerful stimulant that passes into your brain and blocks the action of adenosine, a neurotransmitter that suppresses neuron firing. Consequently, caffeine increases brain activity and thought processes, but it reduces blood flow to the brain and cellular metabolism. Caffeine makes you feel more alert, less drowsy and eager to be active, which certainly gives the impression of an energy boost, but it depletes your energy stores and certain hormones related to your adrenal glands. Furthermore, caffeine is likely to disrupt sleep cycles if you consume it within eight hours of going to bed, which contributes to chronic fatigue and reduced immunity.
Cream and Sugar
Dairy products contain lactose sugar, saturated fat and protein, which are all sources of calories, whereas white and brown sugars are made from sucrose. Coffee laced with cream and sugar, especially strong espresso blends, is one of the most effective and delicious ways of getting an energy boost, at least in the short term. The problem is that lots of cream and sugar spike insulin release, which usually takes too much glucose out of your bloodstream. The result is the infamous “sugar crash,” which leaves you feeling fatigued and grouchy, although the caffeine artificially keeps you going despite low blood sugar levels.
- The Nutribase Complete Book of Food Counts; Art Ulene
- Human Biochemistry; Charles Dreiling
Sirah Dubois is currently a PhD student in food science after having completed her master's degree in nutrition at the University of Alberta. She has worked in private practice as a dietitian in Edmonton, Canada and her nutrition-related articles have appeared in The Edmonton Journal newspaper.