Question

10). The average American consumes almost 2000 pounds of food each year. Luckily, we do not gain 2000 pounds of weight each year! What happens to all the weight (matter) of the food we eat? Where do the atoms in the food molecules go? Use this equation for the overall reaction of the breakdown of glucose to help guide you:

Answer 1

Even though an average person consumes 2000 pounds of food each year, he or she does not gain a weight of 2000 pounds of weight.

This is because the food we eat is utilised for generation of energy and other activities in the body and is not stored as it is

For example let us consider what happens to a molecule of glucose that is consumed.

Glucose is a 6 carbon compound with the molecular formula C₆H₁₂O₆.

When it is taken by the cells of the body it is first broken down to 2 molecules of pyruvic acid which is a 3 carbon compound.

This pyruvic acid further enters the citric acid cycle and is broken down to carbon dioxide and water.

C₆H₁₂O₆ + O₂ à 6CO₂ + 12H₂O + Energy

So, all the atoms in glucose are converted into carbon dioxide and water. Water is used in the body or is evaporated and carbon dioxide is released into the atmosphere.

Similarly all the molecules of food are segregated and are used up accordingly.

So the food material is used up entirely without being added up to the weight of the body.

Therefore whatever may be the amount of food consumed the body weight remains the same. There will be a small change in the weight in growing individuals. Even that weight is ontributed by growing body tissues which in turn use energy obtained from food.

So the amount of food consumed in a period of time will not result in equal increase in weight of the body.