Metabolism and Weight Control

Lean Body Mass
	Fat Free Body Weight
	Skeletal system, organs, muscle, blood, skin

Fat (nothing else)
	Exists in:
		blood
		bone marrow
		around neurons
		below the skin

	Essential Fat
		Required for normal body functions
			Myelin sheath around neurons
			Bone marrow (producing RBC's)
			Around Organs (esp. kidneys)
			Females also add breast and pelvic region
		Average: males = 3%
			females = 12%

	Non-Essential Fat
		Storage Fat - Stored energy
		1 lb. of fat = 3500 calories
			- energy for average male to run 29 miles
		Fat is stored with little H2O
			- high energy with little baggage
		Fat is about 9 calories per gram
			Carbohydrate and Glucose are about 4 calories per gram
		Fat has an insulating effect, in that it keeps blood flow away from the body's surface
			Cannot cool body down as effectively
			Less tolerance to hot climates with excessive body fat

How Fat Develops
	Hypertrophy
		An increase in the size of the fat cells
		Occurs as more and more fat is stored in the cell
	Hyperplasia
		An increase in the number of fat cells
		Occurs when fat cell reaches critical size
			- cannot grow any larger
			- simply breaks into two smaller cells
		Once fat cells are formed, they remain for life
			(only liposuction can remove - yecch!!)
		Theorized that muscle cells do not increase, but remain constant from fetal age of 5 mo.

When Fat Develops
	Most prominent times are:
		1) last three months of fetal development
		2) first year of life
		3) just before puberty occurs (at the end of the final growth spurt)
	However, Can occur throughout ones life.

Causes of Obesity

	1) Hereditary Influence
		- inherit certain body type from parents
			Ectomorph - tall, thin
			Endomorph - short and fat
			Mesomorph - muscular
	2) Lifestyle Influence
		- exercise habits (or lack of)
		- learn eating habits from parents
			Statistics:
				- if no parents are obese, person has 9% chance of being obese
				- if one parent is obese, person has 40-50% chance of being obese
				- if both parents are obese, person has 70-80% chance of being obese
		- moving away to college (Chef Bob's desserts, snacks, late night pizzas, etc.)

Controlling Body Weight

	Control the "Energy Balance Equation"
		Caloric Intake = Caloric Expenditure

	Having a Lower Energy Intake and a Higher Energy Output, one may burn:
		1) Fat
			yeah !!!
		2) Glycogen
			carbohydrate stored with 3.7 grams of water per gram glycogen
		3) Protein 
			not good, as decreasing the protein lowers the metabolic rate
			*** Resistance Exercise stimulates body to maintain specific muscles

	Key to Losing fat, therefore, is DIET and EXERCISE


Dieting

	Typical dieting is usually not effective and can be harmful

	1) Low carbohydrate
		Weight loss is due to water 
	2) High Protein
		Excessive metabolism of proteins by liver (deamination) causes liver damage or failure
	3) Slim - Fast (Diet without Exercise)
		Metabolism of both fat and muscle will occur
		Will lose weight, but will also lose strength

	Again, the Key to Losing fat is a Low-Fat DIET and EXERCISE

	General Recommendations:
		Lose no more than 1-2 lbs per week
		Eat a good variety of foods (vegetables, pasta, etc. - not a good variety of fats)
		Don't eat less that 1000-1200 calories per day
		Eat from all of the food groups

	Specific Recommendations for Daily Calories

				Normal				Dieting

		Fat : 		< 30%				15-25%

		Protein : 	10-12%				< 20%

		Carbohydrates	> 60%				> 60%

	Other:
		Avoid Fried Foods (high in fat)
		Cut down on salad dressings, mayo, gravy, butter, etc.
		Use low or non-fat dairy products
		Alcohol and soda are high in calories
		Eat small meals at night

Role of Exercise in Fat Reduction

	General
		1) Fat does not turn to muscle
			Conversely, muscle does not turn to fat
			Fat is fat, and muscle is muscle
		2) Increase muscle mass increases the metabolism
	Exercise:
		1) Need to involve a large portion of the body's muscle
		2) Keep the activity as continuous as possible
		3) Regulate the intensity to burn fat and prolong fatigue
	Amount of Calories Expended:
		For a 70 kg (154 lb.) male
		Walking 	1 mile			70-75
		Running		""			120
		Swimming	""			360
		Bicycle		"" (10 mph)		80
		Aerobics	(1 hour)			420-630
		Weight Lifting				Very variable
	Benefits of Prolonged (Fat-Reducing) Exercise
		Improves circulatory respiratory function
		Produces desirable changes in blood lipid profiles
			increases HDL's , decreases LDL's
		Increases strength of bones and connective tissues
		Maintains flexibility

Spot Reducing
	What ???: Reducing fat from only one part of the body

	Possible ???:	No.

		Fat is removed somewhat proportionally from the whole body at a time
		Ex: 
			Tennis player muscle hypertrophy of one arm
			Skinfolds were the same on both arms

Other Fads Always Fail - The Energy Balance Equation Always Works - Diet and Exercise