Block 2: Nutritional Status Flashcards
What is nutritional status?
The condition of the body with respect to the availability and use of nutrients
What are the dietary elements?
Proteins, fats, carb, vitamins, minerals
What is energy?
Measured in heat units called calories
What is the calorie and kcal?
Calorie: amount of heat required to raise the temp of 1 g of water by 1C
kcal: amount of heat required to raise the temp of 1 kg of water by 1C
How much energy is provided by dietary elements?
Proteins: provides 4 kcal/g
Fats: provides 9 kcal/g
Carbohydrates: provides 4 kcal/g (Dextrose nutritional bag: 3.4 kcal/g)
Alcohol: provides 7 kcal/g
What is metabolim?
Organized process by which nutrients are broken down, transformed, or otherwise converted into cellular energy
What is anabolism and catabolism?
Anabolism: phase of metabolic storage and synthesis of cell constituents
Catabolism: phase involving the breakdown of complex molecules into substances that can be used in the production of energy.
What are metabolites?
Chemical intermediates of both phases
How is body energy metabolized?
Energy can’t be stored as heat
Convert food components to chemical energy that CAN be stored or dissipated
Carbs, proteins, and fats are transformed into ___?
ATP: energy currecy of the cell
Decreased metabolic efficiency can increase/decrease energy ependitures?
Increase due to uncoupling of ATP synthesis with the mitochondria
Relivent to obesity and maintaining body warmth in newborns
How much body energy is stored in adipose tissue?
90%
What is the main source of stored fuel for the body?
Lipids
What are adipocytes?
Fat cells that cushion orgnas and metabolically active in the uptake, synthesis, storage, and mobilization of lipids
What are pre-adipocytes?
Immature adipocytes capable of dividing post natally resulting in fat deposition
What is lipodystrophy?
Excess loss of fat cells due to apoptosis of adipocytes
What is the difference between white fat and brown fat?
White fat: synthesize TGS from dietary fats and carbs
– Take up glucose in response to insulin
– TG’s breakdown when caloric intake is restricted
Brown fat: differs from white fat, and it’s thermogenic capacity, and its ability to produce heat
Dash higher concentration of specialized mitochondria
What is adipokines?
Exocrine and paracrine Oregon that secretes important factors
What factors do ADIPOKINES secrete?
– Leptin
– Cytokines: TNF alpha
– GF
– Adiponectin: for insulin resistance
What is leptin?
Acts on the hypothalamus (peripheral and CNS receptors) to decrease food intake and increase energy expenditure:
– Increase thermogenesis
– Glucose, metabolism, reproduction, and sexual maturation
– Interacts with HPA, thyroid and growth hormones
What is the function of hypothalamic leptin receptors?
Involved in appetite, food, intake, SNS activity, temperature regulation, and insulin resistance by the pancreatic beta cells
How does SNS activity affect BAT?
Increase SNS activity increases BAT → increase thermogenesis, and energy expenditures
What is leptin resistance?
Resulting in obesity, the failure to respond to high levels of leptin
What are the five mechanisms of thermogenesis?
- Basal metabolic rate.
- Diet induce thermogenesis.
- Exercise induced thermogenesis.
- Non-exercise activity thermogenesis.
- Thermogenesis in response to environmental conditions.
Amount of energy used varies with what?
– Age
– Body
– Rate of growth
– State of health
What is BMR?
Chemical reactions occurring when the body is at rest
What is the function of BMR?
Provides energy for maintaining thermogenesis, CV and respiratory function, and muscular tone
How is BMR measured?
Indirect calorimeter that measures persons use of oxygen
What is average BMR?
65 to 70 Cal/hr in males
5 to 10% lower in women
50 to 70% of body energy needs
How does BMR vary in different people?
Variations in skeletal muscle, mass and body size
– BMR is corrected for body size
– Progressively declines with age due to loss in muscle mass
Skeletal muscles: 20 to 30%
What is resting energy equivalent or REE?
Predicts, energy expenditure