energy needs

• basal metabolic rate is the smallest amount of energy needed for you to stay alive - this is things like breathing and keeping your heart beating
• the basic life processes can use up to about 75% of the energy we use each day -other things like digestion and physical activity make up the rest
• factors that affect a persons basal metabolic rate include:

  • age - BMR decreases as we get older due to reduction of muscle mass
  • sex - females, in general, have a lower BMR than males as they're generally smaller and tend to have less muscle
  • weight and height - heavier or larger bodies need more calories, so have a higher BMR
  • exercise - regular exercise increases muscle which raises your BMR
• your physical activity level is a measure of how active you are / how much exercise you get
• if you are more active, you will have a higher physical activity level than someone with an inactive (sedentary) lifestyle
• BMR and PAL are multiplied together to give your daily energy requirement
• you have to balance your energy intake to maintain a healthy weight:

  • if you consume more energy than you use, you will gain weight
  • if you consume less energy than you use, you will start to lose weight
• this energy balance changes throughout life, for example:

  • as you get older your BMR decreases, so you will need fewer calories to maintain a healthy weight
  • as you exercise more, your PAL increases, so youll need more calories to maintain a healthy weight
• balance of energy sources:

  • carbohydrates - 50%
  • fat - 35% or less
  • protein - 15%
• carbohydrates, fats and proteins are our main sources of energy
• no more than 5% of energy should come from sugar added to processed foods