Chapter 12 energy input

Acrostic: ENERGYAcrostic: ENERGY

=

=

=

=

=

=

EnergyEnergy

Chapter 12: The Energy Balancing ActChapter 12: The Energy Balancing Act

Essential QuestionEssential Question: How do I use the : How do I use the different calculations for energy in dietary different calculations for energy in dietary

planning and the selection of nutrient dense planning and the selection of nutrient dense foods?foods?

GPS: FNW 1CGPS: FNW 1C

FNW 1: Students will discuss basic FNW 1: Students will discuss basic nutrient requirements and their use in nutrient requirements and their use in dietary planning.dietary planning. C: Define a calorie, compare energy sources, C: Define a calorie, compare energy sources,

compute Basal Metabolic Rate, Body Mass compute Basal Metabolic Rate, Body Mass Index, and Waist-to-Hip Ration; apply Index, and Waist-to-Hip Ration; apply outcomes to dietary planning and selection of outcomes to dietary planning and selection of nutrient dense foods.nutrient dense foods.

Key QuestionsKey Questions

What is a calorie?What is a calorie? How do the different energy sources How do the different energy sources

compare?compare? How do I compute Basal Metabolic Rate, How do I compute Basal Metabolic Rate,

Body Mass Index, and Waist-to-Hip Ratio?Body Mass Index, and Waist-to-Hip Ratio? How can I apply BMR, BMI, and Waist-to-How can I apply BMR, BMI, and Waist-to-

Hip Ratios to dietary planning?Hip Ratios to dietary planning?

Key VocabularyKey Vocabulary

Waist-to-Hip RatioSubcutaneousSedentaryOverweightNutrient DenseHealthy WeightEnergyCalorieBody Mass IndexBioelectrical ImpedanceBasal MetabolismBasal Metabolic Rate

Part1:Part1:

What is a calorie?What is a calorie?

Standard: Define calorieStandard: Define calorie

What is a calorie?What is a calorie? Definition –Definition –

Unit of measure Unit of measure A measure of the energy value of food – and of A measure of the energy value of food – and of

how much energy will be transferred to the how much energy will be transferred to the person who eats it.person who eats it.

Amount of energy needed to raise the Amount of energy needed to raise the temperature of 1 kilogram of water (about 4 temperature of 1 kilogram of water (about 4 cups) from 15cups) from 15ooC to 16C to 16ooCC

Calor = heatCalor = heat Calories are NOT a substance present in food Calories are NOT a substance present in food

and do not qualify as a nutrientand do not qualify as a nutrient

What is a calorie?What is a calorie? Caloric value of food:Caloric value of food:

Calories in food are measured by Calories in food are measured by measuring the amount of heat measuring the amount of heat produced when food is burned.produced when food is burned.

Determined in a “bomb calorimeter” by Determined in a “bomb calorimeter” by burning it completely in a container burning it completely in a container surrounded by a certain amount of surrounded by a certain amount of waterwater

A piece of food is precisely weighed, A piece of food is precisely weighed, then it is placed in a calorimeter.then it is placed in a calorimeter.

The chamber holding the food is The chamber holding the food is surrounded by a container holding a surrounded by a container holding a kilogram of water.kilogram of water.

After the food is burned completely, After the food is burned completely, the change in water temperature is the change in water temperature is accurately measured.accurately measured.

Each degree of increase on a Celsius Each degree of increase on a Celsius thermometer equals one calorie of thermometer equals one calorie of energy given off by the foodenergy given off by the food

What is a calorie?What is a calorie?

Researchers have measured the calories in Researchers have measured the calories in a wide range of foods listed in food a wide range of foods listed in food composition tables.composition tables.

Have also determined the energy yield of Have also determined the energy yield of one gram of a pure nutrient:one gram of a pure nutrient:

Carbohydrates and proteins = 4 caloriesCarbohydrates and proteins = 4 calories Fats = 9 calories (means that fats produce Fats = 9 calories (means that fats produce

twice the amount of energy of the other twice the amount of energy of the other two nutrients)two nutrients)

What is a calorie?What is a calorie?

Calorie Density:Calorie Density: Definition – concentration of energy in a foodDefinition – concentration of energy in a food Fats are a concentrated source of energy Fats are a concentrated source of energy

which means that foods that are high in fat which means that foods that are high in fat are calorie denseare calorie dense

Foods that are high in water lack calorie Foods that are high in water lack calorie density because water yields no energydensity because water yields no energy

Part 2:Part 2:Energy SourcesEnergy Sources

How do the different energy How do the different energy sources compare?sources compare?

Energy SourcesEnergy Sources Energy – ability to do workEnergy – ability to do work Cannot be created or destroyed, but can be Cannot be created or destroyed, but can be

changed from one form to anotherchanged from one form to another When you eat, you take in chemical energy When you eat, you take in chemical energy

stored in food and it is changed into stored in food and it is changed into mechanical energy when you move.mechanical energy when you move.

Another form of energy is body heatAnother form of energy is body heat Energy balance is the key to weight Energy balance is the key to weight

management: calories in should equal calories management: calories in should equal calories out in order for weight to not change.out in order for weight to not change.

Energy SourcesEnergy Sources

Energy Input:Energy Input: Consuming foodsConsuming foods Three nutrient groups provide energy:Three nutrient groups provide energy:

Carbohydrates = 43-58% of daily caloriesCarbohydrates = 43-58% of daily calories Fats = 30-45%Fats = 30-45% Proteins = 12%Proteins = 12%

Alcohol provides calories, but is considered a Alcohol provides calories, but is considered a drug, not a nutrientdrug, not a nutrient

Energy SourcesEnergy Sources

Proteins

FatsCarbohydrates

Part 3:Part 3:Energy OutputEnergy Output

How do I compute Basal Metabolic How do I compute Basal Metabolic Rate, Body Mass Index, and Rate, Body Mass Index, and

Waist-to-Hip Ratio?Waist-to-Hip Ratio?

Energy OutputEnergy Output

The calories you burn throughout the dayThe calories you burn throughout the day You need energy for basal metabolism, You need energy for basal metabolism,

physical activity, and thermic effect of physical activity, and thermic effect of foodfood

These three account for the calories you These three account for the calories you expend each dayexpend each day

Energy OutputEnergy Output Basal MetabolismBasal Metabolism

Definition – amount of energy required to support the Definition – amount of energy required to support the operation of all internal body systems except digestionoperation of all internal body systems except digestion

You are burning energy 24/7You are burning energy 24/7 During sleep – internal activity continuesDuring sleep – internal activity continues Your brain and liver use about 40% of your body’s energy Your brain and liver use about 40% of your body’s energy

when resting.when resting. Basal metabolism keeps your body alive when it is at rest Basal metabolism keeps your body alive when it is at rest

and includes the energy your body uses every day to and includes the energy your body uses every day to breathe, circulate blood, and maintain nerve activitybreathe, circulate blood, and maintain nerve activity

Secreting hormones, maintaining body temperature, and Secreting hormones, maintaining body temperature, and making new cells are also part of basal metabolismmaking new cells are also part of basal metabolism

Compares to energy in the home – you still use energy Compares to energy in the home – you still use energy (electric or gas) when no one is home(electric or gas) when no one is home

Energy OutputEnergy Output Basal Metabolic RateBasal Metabolic Rate

BMRBMR Rate at which the body uses energy for basal Rate at which the body uses energy for basal

metabolismmetabolism In general, women require 0.4 calorie per pound In general, women require 0.4 calorie per pound

of body weight per hour and men require 0.5 of body weight per hour and men require 0.5 calorie per poundcalorie per pound

Formulas:Formulas: Men: weight in pounds x 0.5 calorie per pound = basal Men: weight in pounds x 0.5 calorie per pound = basal

energy needs per hour x 24 hours per day = basal energy needs per hour x 24 hours per day = basal energy needs per dayenergy needs per day

Women: weight in pounds x 0.4 calorie per pound = Women: weight in pounds x 0.4 calorie per pound = basal energy needs per hour x 24 hours per day = basal energy needs per hour x 24 hours per day = basal energy needs per daybasal energy needs per day

Energy OutputEnergy Output

Basal Metabolic RateBasal Metabolic Rate Example: woman @ 120 poundsExample: woman @ 120 pounds

120 pounds x 0.5 = 60 x 24 hours = 1440 calories120 pounds x 0.5 = 60 x 24 hours = 1440 calories Example: man @ 120 poundsExample: man @ 120 pounds

120 pounds x 0.4 = 48 x 24 hours = 1152 calories120 pounds x 0.4 = 48 x 24 hours = 1152 calories

Energy OutputEnergy Output BMRBMR

What affects BMR?What affects BMR? Body structure, body composition and genderBody structure, body composition and gender

A tall person will have a higher BMR than a shorter person A tall person will have a higher BMR than a shorter person because the taller person has more body surface area through because the taller person has more body surface area through which heat is lost.which heat is lost.

Body composition – percentage of different tissues in the body Body composition – percentage of different tissues in the body such as fat, muscle, and bonesuch as fat, muscle, and bone

A person with a larger proportion of muscle tissue will have a A person with a larger proportion of muscle tissue will have a higher BMR than someone with more fat tissue – it takes more higher BMR than someone with more fat tissue – it takes more calories to maintain muscle than it does fat.calories to maintain muscle than it does fat.

Males generally have a higher BMR than females because men Males generally have a higher BMR than females because men usually have more lean body massusually have more lean body mass

Temperature (both inside and outside the body)Temperature (both inside and outside the body) Fever increases the BMRFever increases the BMR Adjusting to hot or cold temps in the environment increases BMRAdjusting to hot or cold temps in the environment increases BMR

Energy OutputEnergy Output BMRBMR

What affects BMR?What affects BMR? ThyroidThyroid

Thyroid gland secretes the hormone thyroxine, which regulates basal Thyroid gland secretes the hormone thyroxine, which regulates basal metabolismmetabolism

Overactive thyroid produces too much thyroxine and increases BMROveractive thyroid produces too much thyroxine and increases BMR This is why thyroid diseases can affect a person’s weightThis is why thyroid diseases can affect a person’s weight

AgeAge BMR tends to decline with age – approximately a five percent decrease BMR tends to decline with age – approximately a five percent decrease

in BMR every 10 years past the age of 30in BMR every 10 years past the age of 30 People over the age of 50 must reduce their energy intake up to 200 People over the age of 50 must reduce their energy intake up to 200

calories per day to avoid weight gaincalories per day to avoid weight gain Older people who remain active do not experience as much declineOlder people who remain active do not experience as much decline

DietDiet Diet low in calories decrease BMR about 10-20 percent because the Diet low in calories decrease BMR about 10-20 percent because the

body is responding as if in famine (makes adjustments to preserve life body is responding as if in famine (makes adjustments to preserve life as long as possible)as long as possible)

Will cause difficulty reaching weight goalsWill cause difficulty reaching weight goals

Energy OutputEnergy Output BMRBMR

What affects BMR?What affects BMR? Periods of growthPeriods of growth

Higher during periods of growth – infants, children, and teens have a Higher during periods of growth – infants, children, and teens have a higher BMR than adultshigher BMR than adults

Women have a higher BMR during pregnancyWomen have a higher BMR during pregnancy Due to this – infants, children, teens and pregnant women should not Due to this – infants, children, teens and pregnant women should not

reduce their calorie intake unless advised by a doctor; these groups reduce their calorie intake unless advised by a doctor; these groups need the nutrients provided by a variety of foodsneed the nutrients provided by a variety of foods

Increasing physical activity is a more healthful choice than reducing Increasing physical activity is a more healthful choice than reducing calories for these groups.calories for these groups.

Other Notes:Other Notes: Some of these factors are temporary – pregnancy and feverSome of these factors are temporary – pregnancy and fever You have very little control over these factors which means that you You have very little control over these factors which means that you

have very little control over your BMRhave very little control over your BMR The ONE way to change your BMR – adding a regular exercise program The ONE way to change your BMR – adding a regular exercise program

which will help you develop more muscle tissuewhich will help you develop more muscle tissue Generally the greater the proportion of lean tissue in your body, the Generally the greater the proportion of lean tissue in your body, the

higher your BMRhigher your BMR

Energy OutputEnergy Output Physical ActivityPhysical Activity

This is the second category of energy needsThis is the second category of energy needs You need energy to move your muscles and for the You need energy to move your muscles and for the

extra work of breathing harder and pumping more extra work of breathing harder and pumping more bloodblood

Energy output varies depending on body size – the Energy output varies depending on body size – the larger the body size, the greater the amount of larger the body size, the greater the amount of energy needed to make the muscles workenergy needed to make the muscles work A 180 pound person burns more calories walking than a A 180 pound person burns more calories walking than a

120 pound person walking at the same pace120 pound person walking at the same pace The actual amounts of muscle movement also The actual amounts of muscle movement also

affects energy output – you will burn more energy if affects energy output – you will burn more energy if your swing your arms while walkingyour swing your arms while walking

Energy OutputEnergy Output

Physical ActivityPhysical Activity Sedentary – activities that require much sittingSedentary – activities that require much sitting

Watching TV, studying, working in an office, driving, Watching TV, studying, working in an office, driving, using a computerusing a computer

People who do a lot of sedentary activity need to make People who do a lot of sedentary activity need to make a point of including physical activity in their daily livesa point of including physical activity in their daily lives

Burning more caloriesBurning more calories Try looking for more energy-intensive ways of Try looking for more energy-intensive ways of

completing your daily taskscompleting your daily tasks Taking the stairs instead of the elevator; swing arms Taking the stairs instead of the elevator; swing arms

when walking; stand rather than sit; park further away when walking; stand rather than sit; park further away from destinationfrom destination

Energy OutputEnergy Output Physical ActivityPhysical Activity

Determining Caloric Needs for Physical ActivityDetermining Caloric Needs for Physical Activity Indirect calorimetry – measurement technique requires Indirect calorimetry – measurement technique requires

a person to wear an apparatus while performing a a person to wear an apparatus while performing a specific activity. The apparatus measures the person’s specific activity. The apparatus measures the person’s oxygen intake and carbon dioxide output.oxygen intake and carbon dioxide output.

Oxygen consumption is required to burn calories which Oxygen consumption is required to burn calories which is why you breathe harder when running or working is why you breathe harder when running or working hard.hard.

The researchers then use math formulas to convert the The researchers then use math formulas to convert the gas exchange into calories used.gas exchange into calories used.

Formula for personal energy expended: calories used Formula for personal energy expended: calories used per hour x hours of activity = energy expendedper hour x hours of activity = energy expended

Add all of the calculations together for a 24 hour period Add all of the calculations together for a 24 hour period to determine amount of energy expended per day.to determine amount of energy expended per day.

Running, dancing, bicycling, playing football, playing tennis, cheerleading, swimming, skiing, playing active games

Strenuous

250-350 average 300

Walking fast, bowling, golfing, yard workVigorous

170-240 average 205

Walking moderately fast, making beds, light gardening, standing activities requiring arm movement

Moderate

110-160 average 135

Cooking, doing dishes, ironing, grooming, walking slowly, more strenuous sitting activities

Light

80-100 average 90

Reading, eating, watching TV, sewing, playing cards, using a computer, studying, other sitting activities

Sedentary

60Sleep

Calories Used per Hour

DescriptionActivityEnergy Cost for Various Physical Activities

Energy OutputEnergy Output Thermic Effect of FoodThermic Effect of Food

Third energy needThird energy need Definition – energy required to complete the processes of digestion, Definition – energy required to complete the processes of digestion,

absorption, and metabolism – energy needed to extract the energy from absorption, and metabolism – energy needed to extract the energy from foodfood

Depends slightly on the types and amounts of foods eaten.Depends slightly on the types and amounts of foods eaten. Generally equals 5 to 10 percent of your combined basal metabolism and Generally equals 5 to 10 percent of your combined basal metabolism and

physical activity needs.physical activity needs. Remember – the calorie ranges you used to calculate your energy needs Remember – the calorie ranges you used to calculate your energy needs

for physical activity included basal metabolismfor physical activity included basal metabolism Formula – calculated total energy expenditure for the day by .1 = Formula – calculated total energy expenditure for the day by .1 =

reasonable estimate of energy used for the thermic effect of foodreasonable estimate of energy used for the thermic effect of food For most people, approximately 60-65 % of energy output is for basal For most people, approximately 60-65 % of energy output is for basal

metabolism, 25-35% for physical activity, 5-10% for thermic effect of metabolism, 25-35% for physical activity, 5-10% for thermic effect of foodfood

For athletes, a lower percentage of energy output is for basal For athletes, a lower percentage of energy output is for basal metabolism and a higher percentage for physical activitymetabolism and a higher percentage for physical activity

Calculating total energy needs is difficult for most people, but you can Calculating total energy needs is difficult for most people, but you can use your estimates to help you determine whether you are balancing use your estimates to help you determine whether you are balancing your energy input and output.your energy input and output.

Energy ImbalanceEnergy Imbalance

The two sides of the energy equation are The two sides of the energy equation are not always in balance.not always in balance.

Energy imbalance occurs when a person Energy imbalance occurs when a person consumes too few and too many calories consumes too few and too many calories for his or her energy needs.for his or her energy needs.

A regularly occurring energy imbalance A regularly occurring energy imbalance will cause a change in body weight.will cause a change in body weight.

Energy ImbalanceEnergy Imbalance Energy deficiency – energy intake is less that energy Energy deficiency – energy intake is less that energy

outputoutput Several factors can result in energy deficiency: poverty, Several factors can result in energy deficiency: poverty,

famine, illness, or eating a low-calorie dietfamine, illness, or eating a low-calorie diet The body’s response:The body’s response:

The body first uses energy from carbohydrates, fats, and proteins in The body first uses energy from carbohydrates, fats, and proteins in food to meet its energy needs; if there is not enough available, the food to meet its energy needs; if there is not enough available, the body draws on its stores of energy (liver glycogen – the stored form body draws on its stores of energy (liver glycogen – the stored form of glucose from carbohydrates for use by non-muscle tissue.)of glucose from carbohydrates for use by non-muscle tissue.)

After about 4-6 hours, stores are depleted, the body will After about 4-6 hours, stores are depleted, the body will draw on fatty tissues. Weight loss will occur. The nervous draw on fatty tissues. Weight loss will occur. The nervous system cannot use fat as a fuel source – requires glucose system cannot use fat as a fuel source – requires glucose which cannot be obtained by fatwhich cannot be obtained by fat The body can use amino acids from proteins in lean body tissues to The body can use amino acids from proteins in lean body tissues to

make glucose to feed the nervous system – it has to break down make glucose to feed the nervous system – it has to break down muscle and organ tissues. Muscle tissue is 75% water; therefore muscle and organ tissues. Muscle tissue is 75% water; therefore breaking down muscle proteins causes a rapid weight loss due to breaking down muscle proteins causes a rapid weight loss due to loss of body fluids and can also cause muscle weakness and can lead loss of body fluids and can also cause muscle weakness and can lead to a number of dangerous health consequences.to a number of dangerous health consequences.

Energy ImbalanceEnergy Imbalance Energy deficiency – Energy deficiency –

The body’s response cont.The body’s response cont. When carbs are not available, the body will take steps to limit When carbs are not available, the body will take steps to limit

muscle deterioration.muscle deterioration. It will slowly begin to use another method to feed the nervous It will slowly begin to use another method to feed the nervous

system – by changing fatty acids into compounds called ketone system – by changing fatty acids into compounds called ketone bodies bodies

The nervous system can use ketone bodies to meet some of its The nervous system can use ketone bodies to meet some of its energy needsenergy needs

Reach the nervous system through the blood streamReach the nervous system through the blood stream An abnormal buildup of ketone bodies is called ketosis which can be An abnormal buildup of ketone bodies is called ketosis which can be

harmful because it changes the acid base balance of bloodharmful because it changes the acid base balance of blood Carbs are always important because they are the preferred fuel for Carbs are always important because they are the preferred fuel for

nerve and brain cells to functionnerve and brain cells to function High protein or low carb diets are not recommended because they High protein or low carb diets are not recommended because they

cause muscle tissue to be broken down and large amounts of cause muscle tissue to be broken down and large amounts of ketones to form.ketones to form.

Carb intake should also be sufficient to preserve muscle tissue Carb intake should also be sufficient to preserve muscle tissue which will cause the body to use fat stores, not muscle, for energy which will cause the body to use fat stores, not muscle, for energy and weight loss will occur from the loss of fat, not proteinand weight loss will occur from the loss of fat, not protein

Energy ImbalanceEnergy Imbalance Energy Excess – occurs when energy intake is greater than Energy Excess – occurs when energy intake is greater than

energy outputenergy output Excess calories can be stored in adipose tissue and the body Excess calories can be stored in adipose tissue and the body

can use this stored energy when there is not enough food can use this stored energy when there is not enough food intake to meet immediate energy needs.intake to meet immediate energy needs.

If energy excess occurs on a regular basis, weight gain will If energy excess occurs on a regular basis, weight gain will result.result.

An excess of 3500 calories in the diet leads to 1 pound of An excess of 3500 calories in the diet leads to 1 pound of stored body fat.stored body fat.

Most overweight people have gained weight slowly over a Most overweight people have gained weight slowly over a period of years – consuming an extra 25 calories each day period of years – consuming an extra 25 calories each day adds approximately 2 ½ pounds each year.adds approximately 2 ½ pounds each year.

Excess adipose tissue is a health concern – the greater the Excess adipose tissue is a health concern – the greater the amount of fat carried on the body, the greater the risks for amount of fat carried on the body, the greater the risks for related health problemsrelated health problems

Determining Healthy WeightDetermining Healthy Weight This may not match the media image of a This may not match the media image of a

perfect body – it is the weight at which your perfect body – it is the weight at which your body fat is in an appropriate proportion to body fat is in an appropriate proportion to your lean tissue which reduces your risks of a your lean tissue which reduces your risks of a number of serious medical problems.number of serious medical problems.

Several ways to determine if your weight is Several ways to determine if your weight is healthy:healthy: Height weight chartsHeight weight charts Body Mass IndexBody Mass Index Measuring Body FatMeasuring Body Fat Waist-to-Hip RatiosWaist-to-Hip Ratios

Determining a Healthy WeightDetermining a Healthy Weight Body Mass IndexBody Mass Index

BMIBMI A calculation of body weight and height used to evaluate A calculation of body weight and height used to evaluate

weight.weight. To calculate: divide your weight in pounds by the square of your To calculate: divide your weight in pounds by the square of your

height in inchesheight in inches (145 pounds / 69(145 pounds / 6922 inches) x 705 = BMI inches) x 705 = BMI (145 / 4761) x 705 = BMI(145 / 4761) x 705 = BMI 0.0.05 x 705 = 21.5 (rounded) BMI0.0.05 x 705 = 21.5 (rounded) BMI

There is a chart in your book on page 220 showing estimated BMIThere is a chart in your book on page 220 showing estimated BMI Healthy weight = a BMI of 18.5-24.9Healthy weight = a BMI of 18.5-24.9 Overweight = a BMI of 25-29.9Overweight = a BMI of 25-29.9 Obese = anything over a BMI of 30Obese = anything over a BMI of 30

Underweight = BMI less than 18.5Underweight = BMI less than 18.5 Not an appropriate tool for everyone – body builders Not an appropriate tool for everyone – body builders

have excess muscle weighthave excess muscle weight Less clear-cut for children and adolescents, whose bodies Less clear-cut for children and adolescents, whose bodies

are still growing and vary according to age and sex (see are still growing and vary according to age and sex (see chart on page 221)chart on page 221)

Determining a Healthy WeightDetermining a Healthy Weight Waist-to-Hip Ratios Waist-to-Hip Ratios

Considering the location of excess fat in the bodyConsidering the location of excess fat in the body Some fat deposits are more directly related to health risks Some fat deposits are more directly related to health risks

than othersthan others Apple-shaped -- People who carry more fat around their Apple-shaped -- People who carry more fat around their

middles (most common in women)middles (most common in women) Pear-shaped – carry weight around their hips and thighsPear-shaped – carry weight around their hips and thighs Apple shapes pose a greater risk than pear shapedApple shapes pose a greater risk than pear shaped Formula – measure your waist at its narrowest point, Formula – measure your waist at its narrowest point,

then measure your hips at their fullest point. Divide the then measure your hips at their fullest point. Divide the measurement of the waist by the measurement of the measurement of the waist by the measurement of the hips.hips. Woman with a 28 inch waist and a 38 inch hips: 28/38 = 0.74Woman with a 28 inch waist and a 38 inch hips: 28/38 = 0.74

Waist to hip ratios over 1.0 in men and over .85 in Waist to hip ratios over 1.0 in men and over .85 in women are linked to increased health riskswomen are linked to increased health risks

Determining a Healthy WeightDetermining a Healthy Weight Height-Weight TablesHeight-Weight Tables

Lists a weight range for each heightLists a weight range for each height Weights near the high end of each range apply to people Weights near the high end of each range apply to people

with a greater proportion of muscle and bone tissue – with a greater proportion of muscle and bone tissue – muscle and bone are denser than body fatmuscle and bone are denser than body fat

Weighing less than a height-weight table suggests is not Weighing less than a height-weight table suggests is not always a bad thing, better to be less than more; but it always a bad thing, better to be less than more; but it can indicate a serious health problemcan indicate a serious health problem

DrawbacksDrawbacks They are not precise and not designed for people under the age They are not precise and not designed for people under the age

of 19of 19 Do not take into consideration body composition or individual Do not take into consideration body composition or individual

health riskshealth risks

Determining a Healthy WeightDetermining a Healthy Weight Body Fat Measuring MethodsBody Fat Measuring Methods

Analyzing the percentage of fat in your bodyAnalyzing the percentage of fat in your body For men, over 25 percent is excessive – aim for 15-18%For men, over 25 percent is excessive – aim for 15-18% For women, over 20% aim for 20-25%For women, over 20% aim for 20-25% Skin-fold testSkin-fold test – uses a tool called a caliper to measure the thickness – uses a tool called a caliper to measure the thickness

of a fold of skin; an estimate is then made to determine how much of of a fold of skin; an estimate is then made to determine how much of the thickness is due to subcutaneous fat (fat that lies underneath the the thickness is due to subcutaneous fat (fat that lies underneath the skin, and accounts for about half of the fat in the body); often taken on skin, and accounts for about half of the fat in the body); often taken on the thigh, upper arm, abdomen, and/or backthe thigh, upper arm, abdomen, and/or back

Pinch testPinch test – grasp the skin on the back of your upper arm halfway – grasp the skin on the back of your upper arm halfway between your shoulder and elbow. Pinch this fold between your thumb between your shoulder and elbow. Pinch this fold between your thumb and forefinger. Be sure to grasp only the fat, not the muscle. A and forefinger. Be sure to grasp only the fat, not the muscle. A distance between your thumb and forefinger of more than one inch distance between your thumb and forefinger of more than one inch may indicate a high percentage of body fat.may indicate a high percentage of body fat.

Bioelectrical ImpedanceBioelectrical Impedance – measures the body’s resistance to a low- – measures the body’s resistance to a low-energy electrical current. Lean tissue conducts electricity, whereas fat energy electrical current. Lean tissue conducts electricity, whereas fat does not. The more fat a person has, the more resistance there is to does not. The more fat a person has, the more resistance there is to the flow of the electrical current. The measure of resistance is then the flow of the electrical current. The measure of resistance is then converted to a percentage of body fat.converted to a percentage of body fat.