ENERGY Ch.12

WHAT IS ENERGY Ability to do work. Types of energy: Chemical Mechanical Heat Cannot create or destroy it; can only change form

ENERGY IN CALORIES 3 WAYS TO GET ENERGY CARBOHYDRATES (what your body prefers) FATS PROTEINS

HOW DO I KNOW HOW MUCH ENERGY IS IN MY FOOD? A FOODS CALORIE VALUE IS A MEASURE OF THE HEAT IT GIVES OFF WHEN IT IS BURNED IN A BOMB CALORIMETER! THE ENERGY IT TAKES TO RAISE WATER 1 DEGREE CELISIUS = 1 CALORIE

Calorie Density CONCENTRATION OF ENERGY IN FOOD DIVIDE GRAMS INTO CALORIES THE MORE WATER CONTENT OF FOOD….THE LESS CALORIE DENSE (WATER DOESN’T BURN)

ENERGY OUT Three reasons you need energy. Basal Metabolism Physical Activity Thermic Effect of Food ALL THESE added TOGETHER EQUALS = THE TOTAL AMOUNT OF ENERGY (CALORIES) YOU NEED DAILY

BASAL METABOLISM 60% of your calories are used for this function Basal Metabolism is the amount of energy needed to support the operations of all internal body systems What are some of the ways your body uses basal metabolism? Breathing Blood Circulation Maintaining Nerve Activity Secreting Hormones Maintaining Body Temperature Make new cells

BMR Basal Metabolic Rate is the rate at which the body uses energy for basal metabolism. Women require approximately.4 calorie per pound, per hour Men require.5 calorie per pound, per hour What is your basal energy need?

WHAT EFFECTS BMR? Body structure Body composition – percentage of different tissues in the body; Fat Muscle Bone Gender Age Body Temperature Diet Disease Thyroxine

Physical Activity Need energy to move your muscles Need energy for extra breathes and circulation while working or exercising Energy output varies depending on body size. The larger the body, the more energy is needed. Actual amount of movement of muscles will affect total energy output

PHYSICAL ACTIVITY 30% of your calories are used for this function Sleep You burn 60 calories per hour Sedentary Activities Reading, Eating, Watching TV, Playing cards, Using a computer  You burn calories per hour (average 90) Light Activities Cooking, Doing Dishes, Ironing, Walking slowly  You burn calories per hour (average 135)

Physical Activity cont’d Moderate Activities Walking, Making a bed, light gardening, Standing activities requiring arm movement  You burn calories per hour (average 205) Vigorous Activities Walking fast, Golfing, Yard Work  You burn calories per hour (average 300) Strenuous Activities Running, Dancing, Bicycling, Playing football, Playing Tennis, Cheerleading, Swimming, Skiing  You burn 350 or more calories per hour

Determining Your Calorie Needs for Physical Activity Indirect Calorimetry- measures a persons oxygen intake and carbon dioxide output.

THERMIC EFFECT OF FOOD 10% of your calories are used for this function Energy required to complete the processes of digestion, absorption,and metabolism. Energy required to extract the energy from food. Depends on the types and amount eaten

ENERGY IMBALANCE Occurs when a person consumes too few or too many calories for his or her energy needs.

ENERGY DEFIENCY Occurs when energy intake is less than energy output. Food sources may be scarce. Illness may depress appetite “ Ketone Bodies”- when the body changes fatty acids into compounds to meet energy needs. “Ketosis” –abnormal buildup of ketone bodies in the bloodstream.

Energy Deficiency No carbohydrates to burn as energy, body burns fat (weight loss) Body changes fat into “Ketone Bodies” to use as fuel for the nervous system “Ketosis” is abnormal buildup of ketone bodies in the bloodstream Low carbohydrate diets and starvation will set up a “state of ketosis”. Atkins Diet an example Difficult on kidneys and heart

ENERGY EXCESS Occurs when energy intake is greater than energy output. Body can use stored energy when there is not enough food intake to meet immediate energy needs. If there is excess energy on a regular basis- weight gain occurs 3500 calories = 1 pound of stored fat

LOCATION OF BODY FAT Fat stored in the abdomen seems to pose a greater risk than fat stored in the buttocks, hips, and thighs. Fat around the waist increase the liver’s production of low density lipoproteins, which is a risk factor for heart disease.

KEY TO WEIGHT MANAGEMENT IS BALANCING ENERGY IN WITH ENERGY YOU EXCERT!