"Life is the only game in which the object of the game is to learn the rules." This quote emphasizes the complexity of the human body. When buying a new piece of equipment, a manual or instruction booklet usually accompanies it. The human body however, is an extremely complex machine but does not come with a manual. Ross Pelton (co-author of Drug-Induced Nutrient Depletion Handbook) believes that many people do not begin to understand how their body works until something does not work right, or begins to break down. When the body "breaks down", drugs are often prescribed to help with the condition. Drugs can however, alter the taste and smell of foods, which may change a person's appetite and/or food preferences. Many drugs may decrease the absorption or increase the excretion of certain nutrients. Some drugs may decrease the action of enzymes. The following groups of drugs are listed with the nutrients that they may deplete from the body. If you are taking one of these drugs, you may want to speak to your physician about the possibility of a nutrient depletion if you have not already done so.