F&N

• Energy


  The power to do work
• We all need energy to grow, stay alive, keep warm and be active
• Types of energy required for life

  • Mechanical energy for movement of muscles
  • Chemical energy for all chemical and metabolic reactions
  • Heat energy to maintain body temperature
  • Electrical energy for the transmission of nervous impulses
• Energy expenditure


  • Varies among individuals according to age, gender, occupation and physical activity, and state of the body
• Macronutrients


  Carbohydrate, protein and fat in the food and drink we consume, which provide energy

  
• The amount of energy that each of these macronutrients provides varies
• Energy dense foods


  • Fats (lard, butter, margarine, suet)
  • Oils (vegetable, nut, animal)
  • Fatty foods (egg yolk, cheese, cream, meat)
  • Sugar, cereals, cereal products, starchy vegetables

  
• Carbohydrate (starch and sugars)


  Provides 3.75 kcal (16 kJ) per gram (for the purposes of food labelling this is rounded up to 4 kcal (17kJ) per gram)
• Protein


  Provides 4kcal (17kJ) per gram
• Fat


  Provides 9kcal (37kJ) per gram, the most energy dense nutrient
• Alcohol


  Provides 7kcal (29kJ) per gram
• Energy intake can be estimated by applying these figures to the amount of carbohydrate, protein and fat we consume from food and drink

  
• Per gram, fat provides more than twice the energy of carbohydrate
• Foods


  • Bagel
  • Ham
  • Oil
• Oil contributes the most energy per 100g
• Energy intake


  Measured in joules (J) or kilojoules (kJ), but many people are more familiar with Calories (kcal)
• 1 kilojoule (kJ) = 1,000 joules, 1 megajoule (MJ) = 1,000,000 joules, 1 kilocalorie (kcal) = 1,000 calories
• 1 kcal = 4.184 kJ, a 2000-kcal diet provides 8.368 MJ or 8368 kJ, 1 MJ = 239 kcal
• Basal Metabolic Rate (BMR)


  The amount of energy that is required to keep the body alive when it is at complete rest and warm
• Excess energy is stored as fat
• Estimated Average Requirements (EAR) for energy


  Experts have estimated the average requirements for energy for different types of people
• About 50% of our energy intake should come from carbohydrate, no more than 35% from fat, and around 15% from protein
• EAR variations throughout life

  • Babies, young children and teenagers need more energy in relation to their size to grow and be active
  • After 18, energy requirements decrease and remain the same until 50, but actual needs depend on activity levels
  • Energy requirements for older adults decrease as activity levels fall, and there is a reduction in the basal metabolic rate
• EAR values for children

  • Breast-fed infants 1-2 months, 3-4 months, 5-6 months, 7-12 months
  • Children 1-18 years, by age and gender
• Men generally require more energy than women
• Increasing activity levels would increase energy requirements
• An average adult will use around 1.1kcal each minute just to maintain basic functions
• Infants and young children tend to have a proportionately high BMR for their size due to their rapid growth and development
• Men usually have a higher BMR than women as they tend to have more muscle, and older adults usually have a lower BMR than younger people since their muscle mass tends to decrease with age
• Physical Activity Level (PAL)


  The amount of energy a person uses to perform daily tasks
• PAL values


  • 1.4 - low level of physical activity
  • 1.6 for women, 1.7 for men - moderate intensity activity
  • 1.8 for women, 1.9 for men - high levels of physical activity
• Types of physical activity

  • Activity at work
  • Household chores
  • Looking after others
  • Leisure-time activities
  • Transport
  • Sport
• Children and young people are recommended to do at least 60 minutes of moderate intensity exercise every day
• low level of physical activity at work or during leisure time. This applies to a large proportion of the UK population.
• PAL of 1.6 for women or 1.7 for men


  Represents moderate intensity activity
• Values of 1.8 for women or 1.9 for men

  Represent high levels of physical activity
• What physical activity includes

  • Activity at work, e.g. use the stairs not the lift
  • Household chores, e.g. vacuuming
  • Looking after others
  • Leisure-time activities, e.g. gardening
  • Transport (walking or cycling to school or work)
  • Sport
• Physical activity guidelines for children and young people

  Do at least 60 minutes of moderate intensity exercise every day
• Physical activity guidelines for adults

  1. Do at least 150 minutes of moderate aerobic activity every week or 75 minutes of vigorous aerobic activity

  2. Do strength exercises on two or more days a week that work all the major muscles

  3. Activity does not have to be taken all at once
• Moderate aerobic activity


  Leads to an increase in breathing rate, heart rate, and a feeling of increased warmth