Energy balance

Universidad Iberoamericana

BBA in International Business

Nutrition

Professor: Aurelia Suero

Digestive Process

October 25, 2011

Santo Domingo, Dominican Republic

Energy Balance

Energy balance is defined as “the biological homeostasis of energy in living systems”. In other words is the balance that is achieved between our energy intake and energy release. Energy issimply another word for calories, the balance is set by the calories consumed by eating and drinking compared to the calories that are burned in physical activity. Energy balance is measured by the following equation: Energy intake = internal heat produced +external work +storage; the general energy unit used is calorie.

Energy intake is the part of the diet that is composed of the food andliquids we consume and it’s regulated by hunger. Energy expenditure is the combination of the internal heat produced and the external workout. Internal heat produced is the sum of basal metabolic rate and the thermic effect of food and external work is estimated by measuring the physical activity level.

We must keep in mind that throughout or day we burn calories, by the simple act of breathingair and digesting food we are in the process of burning calories. Nevertheless physical activity is an important part in maintaining energy balance, people who are more physically active burn more calories than those who are not. The rule is that if you consume the same calories you burn then your weight stays the same, if you consume more calories than calories burned then your weight increasesand you burn more calories than the calories consume then you lose weight.

There is the common misconception that our energy has to balance everyday, but this is incorrect what keeps us healthy is having an energy balance over time that keeps us in a healthy weight long term. At the same time we should take into consideration that the amount of calories needed varies from sex, age and physicalactivity. The amount of calories that a children need is obviously not the same as the amount of calories a 50 year-old men needs, there are certain guidelines and different methods to calculate the amount of calories needed per person. One of this guidelines is the Estimated Calorie Requirements for each gender and age group, as we will see in the graph below there are various factors thatcontribute to the amount of calories needed for a person.

Estimated Calorie Requirements (in kilocalories) for Each Gender and Age Group at Three Levels of Physical Activity.
|Gender |Age (years) |Activity Level |
| | |Sedentary|Moderately Active |Active |

|Child |2-3 |1,000 |1,000 - 1,400 |1,000 - 1,400 |
|Female |4 - 8 |1,200 |1,400 - 1,600 |1,400 - 1,800 |
|Female |9-13 |1,600|1,600 - 2,000 |1,800 - 2,000 |
|Female |14-18 |1,800 |2,000 |2,400 |
|Female |19-30 |2,000 |2,000 - 2,200 |2,400 |
|Female |31-50|1,800 |2,000 |2,200 |
|Female |51+ |1,600 |1,800 |2,000 - 2,200 |
|Male |4-8 |1,400 |1,400 - 1,600 |1,600 - 2,000 |
|Male...