Nutrition & Energy Flashcards
What is energy?
it can’t be created or destroyed, only converted from one form to another
How is energy obtained?
by oxidation of macronutrients (carbohydrates, fat, protein and alcohol)
What is chemical energy used for?
-used by body to carry out mechanical (muscle contraction), electrical (maintaining ion gradients across membranes) and chemical (synthesis of new macromolecules)
How many kj is in 1 kcal?
4.18kj
What factors can affect energy requirements?
sex, body size, climate, physical activity levels
How many kcal per gram of fat?
9 kcal (most energy dense)
how many kcal per gram of protein?
4 kcal
how many kcal per gram of carbohydrate?
3.75kcal
How many kcal per gram of alcohol?
7 kcal
What does EAR stand for?
estimated average requirements
What % of the diet does COMA recommend come from each micronutrient without alcohol (with alcohol)?
50% (47%) from carbs
35% (33%) from fat
15% (doesn’t change) from protein
Effect of age on energy requirements?
Generally decrease as age increases –decreases at 18 and remains the same till 50 then decrease again as basal metabolic rate decreases
What form is energy stored in in the body?
fat, glycogen, protein
(protein is only used by the body in extreme cases eg.starvation-muscles waste away)
What is energy expenditure?
-the sum of the basal metabolic rate , the thermic effect of food and the energy expended in physical activity.
what is BMR?
the amount of energy expended while at complete rest (the total number of calories the body needs to be able to carry out basic life functions)
what is the thermic effect of food?
the energy required to digest and absorb food
What % of energy should be expended by BMR, thermic effect of food and physical activity?
-60-75%- BMR
-10% thermic effect
-15-30%-physical activity
How is body weight maintained in terms of energy?
energy intake= energy expenditure
What is negative energy balance?
-when diet provides insufficient energy to meet energy demands of person and causes weight loss
-if happens over a long period of time can cause someone to be underweight
What health problems can be caused from being underweight?
-osteoporosis (low bone mass)
-infertility (hard to conceive)
-anemia
-slow/impaired growth
What is positive energy balance?
-when the diet provided more energy than needed so excess energy is stored as fat causing a person to gain weight
-over an extended period of time the person may become overweight and obese
Health risks associated with being overweight?
-increased risk of developing certain cancers
-cardiovascular disease
- type 2 diabetes.
- If a large amount of weight/fat is stored around the waist that also
increases the risk of these health problems.
How can energy balance be maintained?
.Regulating energy intake through the diet
* Adjusting physical activity levels
* A combination of both
