Energy and energy balance

Question 1

what are 5 reasons why the body needs energy?

Answer 1

-physical activity and making muscles move
-body temperature
-bodily functions e.g. heartbeat
-growth and repair of body tissues
-meeting specific needs e.g. pregnancy and illness recovery

Question 2

what are the 9 factors that affect energy requirements?

Answer 2

-age
-gender
-physical activity
-pregnancy
-illness
-body composition
-hormone imbalance
-thermogenic effect of food
-BMR

Question 3

why does age influence energy requirements?

Answer 3

-younger children have higher metabolic needs and need more energy than adults
-this is because they are more active and are growing rapidly
-the older we become the less energy we need as there is a reduction in physical activity and lean body mass (everything except fat)
-energy requirements for growth are the biggest in the first 3 months of life at 35%

Question 4

why does gender influence energy requirements?

Answer 4

-men need more energy than women as they have a larger overall body size and surface area
-larger body size is linked with a greater energy expenditure, larger bodies need more energy to keep them warm
-large muscles and bone need more energy for movement than a smaller body

Question 5

why does physical activity influence energy needs?

Answer 5

-sedentary lifestyle e.g. office workers, need less energy as they are moving less
-active lifestyle e.g. builders have the largest energy requirements
-some activities use more energy than others because they exercise more muscles and require the body to work hard

Question 6

why does pregnancy influence energy needs?

Answer 6

-more energy is needed to ensure the healthy growth and development of the fetus, uterus and breast tissue
-this extra energy only amounts to 200kcal in the third trimester only.
-during lactation an extra 400-800 kcal is needed each day to ensure sufficient milk production with the right energy content of the milk

Question 7

why does illness and disease influence energy requirements?

Answer 7

-if the body has a fever the metabolic rate rises, during the fever the body attempts to reduce the temp by 1 degrees which increases basal metabolic rate by 10%
-fever drains energy stores which is why people lose weight when they are ill

Question 8

why does body composition influence energy needs?

Answer 8

-lean body tissue (muscle) is more metabolically active and uses more energy than adipose (fatty) tissue
-individuals who have more lean body tissue are more likely to burn off excess energy

Question 9

why does hormone imbalance influence energy needs?

Answer 9

-hormones help regulate metabolism
-thyroid gland secretes hormones which regulates metabolic processes
-overactive thyroid increases metabolic rate and individuals may need to consume more energy to help this imbalance
-underactive thyroid slows metabolism as the gland doesn’t release enough hormones

Question 10

what are symptoms of an underactive thyroid?

Answer 10

-weight gain
-depression
-constipation

Question 11

why does the thermogenic effect of food influence energy needs?

Answer 11

-intake of food stimulates metabolism causing an increase in metabolic rate as the body digests food eaten
-the energy produced as heat is known as the thermogenic effect
-this effect of food is greater with protein and carbohydrate than with fats
-this effect accounts for 10% of energy expenditure daily

Question 12

what does BMR stand for and what does it mean?

Answer 12

-amount of energy needed in order to maintain functions e.g. heartbeat, breathing and body temp, when the body is totally at rest
-accounts for 75% of energy needs
-young children have a proportionally high BMR to meet demands of growth
-men have higher BMR than women as they have a greater muscle mass
-older adults have a lower BMR as muscle mass decreases

Question 13

what does EAR stand for?

Answer 13

-estimated average requirements

Question 14

what is EAR linked to and how is it calculated ?

Answer 14

-all energy requirements are linked to individual basal metabolic rates and their physical activity levels
-EAR=BMR x PAL

Question 15

what does DRV stand for and what does it mean?

Answer 15

-dietary reference value
-comprised of a series of estimates of the amount pf energy and nutrients needed by different groups of healthy people in the UK population

Question 16

what is energy balance?

Answer 16

-when energy intake and expenditure are equal and so maintains a constant weight

Question 17

what is a positive and negative energy balance?

Answer 17

-a positive energy balance is when energy intake is greater than energy output which can lead to weight gain as excess calories are stored as fat
-a negative energy balance is when energy output is greater than energy intake which results in weight loss as the fat stores in the body are used- this can happen during a period of illness

Question 18

why should energy dense foods be avoided?

Answer 18

-energy dense foods are high in calories and offer little to no nutritional benefits e.g. confectionary, instead nutrient dense foods should be eaten e.g. wholegrain bread, lean meat and low fat dairy products

Question 19

what are 3 ways in which energy intake can be monitored to maintain a healthy weight?

Answer 19

-maintain regular eating patterns to avoid unnecessary grazing on HFSS foods
-cooking meals can contribute to the energy content of food, boil and steam where possible as its healthier
-read food labels to avoid HFSS foods

Question 20

how can portion size influence energy balance?

Answer 20

-all food contain calories even of they are healthy
-many overestimate size while underestimating calorie content
-they also eat with their eyes which can lead to a excessively larger portion which can lead to weight gain

Question 21

how can BMR influence energy balance?

Answer 21

-it is important to consider BMR when trying to achieve a healthy weight e.g. a decrease in BMR in older adults mean that energy needs decrease which corresponds with reduced energy intake to avoid weight gain

Question 22

how can PAL influence energy balance?

Answer 22

-PAL will be different on the type, amount and intensity of physical activity

Question 23

what are the calories found in fat, protein and carbohydrates?

Answer 23

-fat= 9kcal
-carbohydrate= 4kcal
-protein= 4kcal

Question 24

what is the main source of energy in the diet and why is it important?

Answer 24

-starchy carbohydrates are the best thing to consume to meet energy needs
-they are a source of slow release energy, which help keep blood sugar levels constant, and provide a feeling of fullness, they also provide b group vitamins which assist the release of energy from food

Question 25

what percentage of the diet should come from carbohydrates, proteins and fats ?

Answer 25

-carbs should be 50% with no more than 5% of which should be free sugars
-fat should be 35% with no more than11% from saturates
-protein is 15%