Energy

How many kcal in a kJ?

1kcal=4.184 kJ

joule

1kg moved 1m by a force of 1 Newton

kilocalorie

heat required to increase the temperature of 1kg of water 1C

calorie

heat required to increase temperature of 1mL of water 1C

bomb calorimeter

food burned in a crucible and energy is calculated by how much the water bath temperature increases; the degree of rise determines cals but this doesn’t accurately represent the human body

What is energy intake?

metabolized energy of food eaten

What does energy expenditure refer to?

the hydrolysis of ATP

What are the components of energy expenditure?

Exercise, Resting Energy Expenditure, Thermic Effect of Food, thermoregulation

Energy Balance

Zero Balance: intake= output

Factors that affect energy balance

genetics, chemicals, organs, lifestyle: diet, lifestyle: behavior

components of energy intake

food and beverage choice and amount

energy available depends on how well you chew, whether the food is cooked or uncooked, and how processed the food is

components of energy output

absorption

metabolism

breathing

storage efficiency

heart beating

heating/cooling body

exercise

orexigenic hormones

increase or stimulate the appetite

anorexigenic hormones

leptin

produced in white adipose tissue

decreases the urge to eat and increases physical activity to produce a negative energy balance

Levels increase with overfeeding or increased adipose tissue and decrease with starvation

Gherkin

produced in the stomach and duodenum

stimulates hunger and food intake; promotes digestion

levels increase between meals and decrease after a meal when absorption begins

glucagon-like peptide 1

suppresses hunger and inhibits glucagon production

peptide YY

suppresses hunger in the long term

cholecystokinin

suppresses appetite and promotes satiety

pancreatic polypeptide

suppresses hunger in the short term

adiponectin

protects against insulin resistance, glucose intolerance, and dyslipidemia