2.3.3

Energy Needs

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Basal Metabolic Rate and Physical Activity Level

Basal metabolic rate (BMR) and physical activity level (PAL) are measures of energy requirement and activeness respectively.

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Basal metabolic rate (BMR)

  • BMR - the absolute minimum level of energy required to stay alive. It covers basic life processes, like breathing and maintaining a heartbeat.
  • These processes can take up almost 75% of our daily energy use. The rest is used up by processes like digestion and physical activity.
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Factors affecting BMR

  • Age - our muscle mass reduces with age. This causes BMR to decrease.
  • Gender - as women are generally smaller and have less muscle mass than men, they tend to have lower BMRs than men.
  • Exercise/physical activity - the more a person exercises, the more muscle they'll build up. This will raise their BMR.
  • Height and weight - the larger or heavier a person's body, the more calories they need and the higher their BMR.
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Physical activity level (PAL)

  • PAL - a measure of how much exercise someone does or how active they are.
  • The more active a person, the higher their PAL will be.
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Daily energy requirement equation

  • Daily energy requirement (kcal) = BMR × PAL
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Balancing energy intake

  • To stay at a healthy weight, a person must balance their energy intake.
    • A person will gain weight if they consume more energy than they use.
    • A person will lose weight if they consume less energy than they use.

Jump to other topics

1Food Preparation Skills

2Food, Nutrition & Health

3Food Science

4Food Safety

5Food Choice

6Food Provenance

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