7.4: Human Energy Needs Change

Metabolic needs - the needs that your body requires in order to stay alive

As people move through stages of life, their metabolic needs change. 

Before birth - The baby depends on the mother to provide sufficient nutrients. The nutrients are delivered through the umbilical cord which is attached from the mother to the fetus. 

Birth - Babies require specific nutrients in order to thrive. Although the best source of food is breast milk, artificial milk formulas simulate breast milk because the necessary nutrients and minerals are added to the milk formula. Both breast milk and formula are the best source of energy they need to grow. 

Childhood - Metabolic needs change with every growth spurt and development stage.  

Puberty - Large amounts of energy are required to support an increase in height, mass, and mature sexually and physically. 

Pregnancy - With the mother supplying nutrients for their own energy needs and their babies, they must make sure they feed themselves enough. Some nutrients are particularly important during pregnancy because of the amount these nutrients are needed for the growth and development of the fetus.

Breastfeeding - Women who are breastfeeding have a higher metabolism and there for need more nutrients because they are providing nutrients for both themselves and their infant(s). 

Athletes - As previously discussed, athletes require more energy as their metabolic needs adjust during exercise and competition. 

Seniors - As people age, their bodies require more of specific nutrients in order to overcome the effects of aging. 

How can you avoid gaining weight when your metabolism drops?

• Keep active by taking long walks, swim, cycle

• Reduce food intake

When someone chooses to cut back on food, they should reconsider their dietary habits. Cutting back on food may reduce the amount of nutrients that are needed to maintain strong bones and teeth, maintain sufficient iron levels, and any number of other nutrients required for normal body functions. 

Check Your Understanding

1. In your own words, define metabolism.

2. Describe some of the differences in nutrient and energy requirements between a baby and a senior citizen.

3. List three occupations in which you would expect workers to have high metabolisms

4. For each of the following situations, predict whether the person's metabolic rate will go up, down, or stay the same:

   1. A construction worker resigns and takes on a rural mail route.

   2. A mother stops breastfeeding.

   3. A high school gymnast begins training for the provincial finals.

   4. A weightlifter takes time off from training.