Chapter 12 Nutrition Food and Fitness The Energy Balancing Act

Energy  Energy: is the ability to do work.  Energy cannot be created or destroyed.  Energy can be changed from one form to another.  When a person eats, they take in chemical energy.  The body changes chemical energy to mechanical energy.  You use this mechanical energy to do daily tasks.

Energy Input  This side of the energy balance equation is the food you consume.  Three food groups provide energy  Fats, Carbohydrates, and Proteins  We measure this energy in food and call it calories.  Calories are the amount of heat energy it takes to raise 1 Liter of water 1 degree Celsius  Food Calories are the amount of energy available from food that is available through digestion & respiration of nutrients.

Energy Output  Energy Output is equal to energy expended through out the day.  Sleeping  Walking  Breathing  Sitting  Taking a test  Running  Studying  Laughing

Energy Output

Basal Metabolism  Basal Metabolism is the amount of energy required to support the operation of all internal body systems except digestion.  Basal Metabolism keeps your body alive when it is at rest.  Ex: Breathing, blood circulation, nerve functioning, maintain body temperature, secreting hormones, and making new cells

Basal Metabolism Rate (BMR)  BMR is the rate at which the body uses energy for basal metabolism.  For regular body functions  Women Average 0.4 calories per pound, per hour  Men Average 0.5 calories per pound, per hour

Basal Metabolic Energy Needs  To find Basal Metabolism=  Weight in pounds x BMR  BMR  Women = 0.4 calories per pound  Men = 0.5 calories per pound

Basal Metabolism Rate (BMR)  Affected by:  Height  Body Composition ( fat, muscle, and bone)  (muscle tissues have higher BMR rates than fat tissues)  Internal and External Temperatures  Thyroid Gland  Age (BMR declines with age)  Stage In Life Cycle

Energy Balancing Act  Energy In = Energy Out  Weight stays the same  Energy In exceeds Energy Out  Weight will increase  Energy Out exceeds Energy In  Weight will decrease

Energy Balancing Act  1 pound = 3,500 Calories  Excess of 3,500 calories = 1 lb of stored body fat  Burning 3,500 calories = burn 1 lb of body fat  Obesity and Underweight  Usually gradually happens over time

Energy in Foods  Remember!  Calories are a measure of heat energy  9 Calories come from every gram of fat  4 Calories come from every gram of carbohydrates  4 Calories come from every gram of protein

Physical Activity  You need energy to move and function.  Energy output depends on weight.  Actual amount of muscle movement affects energy output.

Physical Activity  Sedentary “Activities”  Sitting, TV, studying, working in an office, driving, typing  Lifestyles where sedentary activities are common should find ways to increase their physical activity  Standing, stairs, bike, extra walking etc

Physical Activity  Aerobic Activity - “ using oxygen”  vigorous activity that increases the heart and lungs sending more oxygen to the muscles  Presence of oxygen also permits the body to metabolize fat.  EX: Walking, jogging, dancing, swimming  Anaerobic Activity- “ without oxygen”  short intense bursts of activity  Muscles work hard and quick  EX: 100 meter dash, resistance training, weight lifting

Physical Activity ActivitiesCalories per Hour  Sleep 60 calories  Sedentary Activities calories Reading, eating, watching tv, sewing, playing cards, using computer, studying  Light Activities calories Cooking, dishes, ironing, grooming, walking slowly  Moderate Activities calories Standing activities requiring arm movements, walking moderately fast  Vigorous Activities calories Walking fast, bowling, golfing, yard work  Strenuous Activities 350+ calories Running, dancing, bicycling, football, tennis, cheerleading, swimming, skiing

Digestion and Calories Burned  Digestion accounts for about 10% of total energy expenditure daily.  Ex: 2,500 calorie diet uses about 250 calories for digestion.

Healthy Weight  Tools to measure Healthy Weight  Body Mass Index  Body Fat Percentages

Body Mass Index  Body Mass Index (BMI) uses a ratio of weight to height.  The formula for finding BMI is BMI= weight in lbs x 703 (height in inches) 2

Body Mass Index  BMI is a measure of height and weight  Overestimates of body mass for vary muscular people  Athletes, body builders, those with a large muscle mass  This means that a professional body builders BMI will probably be classified as overweight or obese due to the fact that muscle weighs more than fat.

Body Fat Percentage Relation of fat in the body in comparison to muscle.  Healthy Body Fat Percentages are  18-25% for males  21-24% for females  Percentages over these are considered overweight  Percentages under these are considered underweight.  Professional Athletes average at 8% for males 18% for females

Body Fat Percentage  Skinfold Test  Caliper

Body Fat Percentage  Bioelectrical Impedance  Send electric impulses through body  Lean tissues conduct electricity better than fatter tissues.  The more resistance the current encounters the more fat present in the body.

Body Shapes and Body Fat  What shape am I?  “Pear Shaped”- store fat in hips & thighs  “Apple Shaped”- store fat primarily in abdomen

Body Shapes and Body Fat  Where is the fat?  Studies show that fat around the abdomen increases the liver’s production of lipoproteins which increases a person’s risk for heart disease.

Keeping a Healthy Weight  Ideal Body Myth  Average super model is 5’ 10’’ and 120lbs  Average American adult is 5’ 4’’ and 152 lbs  Overweight epidemic  Fast foods  Processed foods  Sedentary lifestyles

Health Risks  Underweight  Depletes the body of muscle and fat  Muscle loss= fatigue & injury to bones and joints  Fat loss=loose nutrient stores, weakened immune system, hormonal imbalance

Health Risks  Overweight  Strain on muscles, bones & internal organs  High blood pressure, heart disease and stroke  Early death  Overweight epidemic  Fast foods  Processed foods  Sedentary lifestyles

So Why Is Weight On The Rise?  Advertisements and television  Supermarket aisles and vending machines  High calorie fast food and highly processed foods.  Larger serving sizes

Behavior Modification  The most successful way to achieve weight loss is through behavior modification.  Making gradual permanent changes in eating and activity habits.  Limiting calories and increasing activity are the two essential parts

Changing Eating Habits  Variety of foods  Choose healthy snacks  High fiber content  Drink enough liquids daily  Don’t skip meals  Watch portions Eat in moderation Eat in moderation Limit high calorie drinks and snacks Limit high calorie drinks and snacks Fat-free doesn’t necessarily mean lower calories Fat-free doesn’t necessarily mean lower calories

Commercial Weight Loss Plans  Fad Diets- popular weight loss methods that ignore sound nutrition principles  Usually guarantee dramatic results