Our bodies are finely tuned machines and like most machines our bodies need fuel. All the energy that our bodies need comes from the foods that we eat. So, if you deprive your body of any of the three sources of energy (proteins, fats and carbohydrates), it won't run efficiently. That is why a well balanced diet is so important. According to University of Illinois At Urbana Campaign, some cells in our bodies use carbohydrates exclusively for energy, so our bodies have devised a complex way to turn proteins and fats into energy too. Meaning we need all three of these "macronutrients" to survive. Our bodies also have a way of prioritizing: burning carbohydrates first, then fats and finally proteins.
Carbohydrates provide our bodies with its main source of energy. There are two types of carbohydrates: simple and complex. Vision Learning explains that simple carbohydrates are either monosaccharides or disaccharides, more commonly known as fructose and glucose. Complex carbohydrates contain simple sugars, except that they are in the form of long chains known as polysaccharides. Most polysaccharides contain starch (pasta and potatoes) and take longer for the body to break down. Thus, the quickest amount of energy comes from simple carbohydrates such as those found in fruit.