Rapid Tone Always prepared meals for your lunch and snacks the night before so you can grab and go. After buying groceries, and cut all the vegetables and place them in containers to be ready to grab and go. This may be a little work, but think of all the money you save and all the calories you save by so doing a little bit of prep work. The digestive system is the series of tubelike organs that convert our meals into body fuel. In all there's about 30 feet (9 meters) of these convoluted pipeworks, starting and the mouth and ending and the anus. Along the way, food is broken down, sorted, and reprocessed before being circulated around the body to nourish and replace cells and supply energy to our muscles. Food on the plate needs to become a mashed-up, gooey liquid for the digestive system to be able to split it up into its constituent parts: proteins, carbohydrates, fats, vitamins, and minerals.