BIOD 121 Module 3 Nutrition
3.1 Energy Balance:
● Energy balance
○ Defined as a state when one energy intake is equivalent to the amount of energy
expanded
■ Number of calories ingested from food/drink = number of calories burned
through basic body functions and exercise
■ Help maintain appropriate weight
● Positive energy balance
○ More calories are consumed than expended
○ Need this during periods like preganancy or growth spurts
○ Weight gain, one pound of fat is 3500 kcal
● Hyperplasia: increase in the number of fat cells often occuring during periods of growth,
such as adolescence or pregnancy
● Hypertrophy: increase in the size of fat cells, most often occuring during periods of low
growth and maintenance, such as through adulthood. ● Negative energy balance
○ Few calories are consumed than calories expanded
○ Illness, brain injury
○ Usually an intentional act to lose weight ●
Energy expenditure
○ Sole source of energy is from food and beverages
○ Energy can be expended naturally via basal metabolism, the thermic effect of food,
and thermogenesis as well as intentionally through physical activity.
■ Combo of these components determines the number of calories that are
burned or expended on a daily bases
○ Two major components of energy expenditure are basal metabolic rate and
physical activity.
● Basal metabolic rate (BMR)
○ Defined as the number of calories used by the body while in a fasting state and
accounts for approximately 60-70% of energy expediure
○ Males require 1 kcal/kg/hour and female require .9kcal/kg/hr to support the function
of various organ to stay alive
○ Varies per person based on a number of factors such as: gender, lean body mass,
body size, temperature, age, nervous system activity, levels of caffeine intake,
tobacco use
○ If we restrict our calories intake too much, our BMR declines to prevent starvation
○ Naturally declines 1-2% per decade ● Thermic effect of food (TEF)
○ Or nonexcercise activity thermogenesis (neat) is the ability to regulate body
temperature and physical activcity that is involuntary such as fidgeting and
shivering.
○ Amt of energy burned through thermogenesis is small
, ○ Lean adults have more brown adipose tissue (like infans have), brown fat
metabolizes the energy yielding nutrients which results in heat production to be used by
the body ● Physical activity
○ Account for 15-40% of our energy expenditure
○ Number of factors like body suze, fitness level, actual activity, determine how many
calories are expended
○ Previous generations expended many more calories than we do today as jobs
were more physically demanding ● Determining energy needs
○ To maintain a healthy weight, first need to understand how many calories our body
needs on a daily basis
○ Amt of energy can be measured directly and indirectly ○
Direct calorimetry
■ Amount of heat given off by the body
■ Insulated chamber surrounded by a thin layer of water is used to measure
the amount of heat emitted by the subject in the chamber
■ This method not used a lot due to the expense and complexity of the
procedure
○ Indirect calorimetry
■ Uses oxygen intake and CO2 output, along with scientific formulas to
measure energy expended
■ Convenient, fairly cheap, easy, portable
○ For general population, formulas may be used to calculate the amt of energy
required daily per individual
■ Based on gender, age, height, weight, activities
■ To determine indivudal energy requirements, multiply the BMR x PA =
number of calories required to expend daily to maintain current weight
● PA estimates:
○
3.2 Approaches to Determining Healthy Body Standards:
● Height to eright tables
3.1 Energy Balance:
● Energy balance
○ Defined as a state when one energy intake is equivalent to the amount of energy
expanded
■ Number of calories ingested from food/drink = number of calories burned
through basic body functions and exercise
■ Help maintain appropriate weight
● Positive energy balance
○ More calories are consumed than expended
○ Need this during periods like preganancy or growth spurts
○ Weight gain, one pound of fat is 3500 kcal
● Hyperplasia: increase in the number of fat cells often occuring during periods of growth,
such as adolescence or pregnancy
● Hypertrophy: increase in the size of fat cells, most often occuring during periods of low
growth and maintenance, such as through adulthood. ● Negative energy balance
○ Few calories are consumed than calories expanded
○ Illness, brain injury
○ Usually an intentional act to lose weight ●
Energy expenditure
○ Sole source of energy is from food and beverages
○ Energy can be expended naturally via basal metabolism, the thermic effect of food,
and thermogenesis as well as intentionally through physical activity.
■ Combo of these components determines the number of calories that are
burned or expended on a daily bases
○ Two major components of energy expenditure are basal metabolic rate and
physical activity.
● Basal metabolic rate (BMR)
○ Defined as the number of calories used by the body while in a fasting state and
accounts for approximately 60-70% of energy expediure
○ Males require 1 kcal/kg/hour and female require .9kcal/kg/hr to support the function
of various organ to stay alive
○ Varies per person based on a number of factors such as: gender, lean body mass,
body size, temperature, age, nervous system activity, levels of caffeine intake,
tobacco use
○ If we restrict our calories intake too much, our BMR declines to prevent starvation
○ Naturally declines 1-2% per decade ● Thermic effect of food (TEF)
○ Or nonexcercise activity thermogenesis (neat) is the ability to regulate body
temperature and physical activcity that is involuntary such as fidgeting and
shivering.
○ Amt of energy burned through thermogenesis is small
, ○ Lean adults have more brown adipose tissue (like infans have), brown fat
metabolizes the energy yielding nutrients which results in heat production to be used by
the body ● Physical activity
○ Account for 15-40% of our energy expenditure
○ Number of factors like body suze, fitness level, actual activity, determine how many
calories are expended
○ Previous generations expended many more calories than we do today as jobs
were more physically demanding ● Determining energy needs
○ To maintain a healthy weight, first need to understand how many calories our body
needs on a daily basis
○ Amt of energy can be measured directly and indirectly ○
Direct calorimetry
■ Amount of heat given off by the body
■ Insulated chamber surrounded by a thin layer of water is used to measure
the amount of heat emitted by the subject in the chamber
■ This method not used a lot due to the expense and complexity of the
procedure
○ Indirect calorimetry
■ Uses oxygen intake and CO2 output, along with scientific formulas to
measure energy expended
■ Convenient, fairly cheap, easy, portable
○ For general population, formulas may be used to calculate the amt of energy
required daily per individual
■ Based on gender, age, height, weight, activities
■ To determine indivudal energy requirements, multiply the BMR x PA =
number of calories required to expend daily to maintain current weight
● PA estimates:
○
3.2 Approaches to Determining Healthy Body Standards:
● Height to eright tables
