Weight Management

Question 1

Know the difference between overweight, underweight, and obesity. What are the problems associated with all three?

Answer 1

Overweight
- Weight between 10% and 20% above the desirable weight for height, or a body mass index (BMI) of 25 through 29.9

Obesity
- Weight 20% or more above the desirable weight for height, or a BMI of 30 or greater

Underweight
- Weight 10% or more below the desirable weight for height, or a BMI of less than 18.5

Problems:
Underweight:
- Minimal body fat stores
- Decreased energy reserves during times of physiological stress or injury.
- Menstrual irregularity
- Infertility
- Osteoporosis

Overweight/Obesity:
- Abdominal hernias
- Certain cancers: colon, rectal, prostate, breast, uterus, cervical, ovarian
- Complications during pregnancy
- Complications during surgical procedures
- ↓ Longevity

• ↓ Quality of life
• Depression
• Type 2 Diabetes
• Fertility problems
• Gallbladder & liver disease
• Heart Disease
• ↑ Blood cholesterol levels
• Hypertension
• Osteoarthritis (In joints; have trouble bending, etc.)
• Respiratory problems

Question 2

Be able to calculate Body Mass Index and know the clinical guidelines for BMI.

Answer 2

• BMI is an index of a person’s weight in relation to height.

How to calculate BMI:
- BMI= weight (kg)/ height (m^2)
- BMI= weight (lbs)/height (in^2) times 703

Classification: BMI (kg/m^2):
- Underweight: < 18.5
- Normal (Healthy): 18.5-24.9
- Overweight: 25-29.9
- Obese: 30-39.9
- Severely Obese: >= 40

Look at pg 2 from Final Review Fall 2023

Question 3

How does body fat distribution play a role in risk for disease? Know how to calculate waist-to-hip ratio.

Answer 3

Estimated Disease Risk:
- Waist Circumference
- Men >40 inches
- Women >35 inches

Waist-to-hip Ratio
- Men >1.0
- Women >0.8

Look at pg. 3 from Final Review Fall 2023

Question 4

What are the different ways to measure body fat (as discussed in class) and how do they work? Watch the videos in D2L to help with this concept.

Answer 4

Hydrostatic (underwater) weighing: the less a person weighs underwater compared to the person’s out-of-water weight, the greater the proportion of body fat.
- Fat is less dense (more buoyant) than lean tissue. (fat weighs less underwater)

Skinfold test: thickness of a fold of skin is measured using a caliper.
- Back of the arm (triceps), below shoulder (subscapular)

Bioelectrical impedance:
- Measures how quickly electrical current is conducted through the body.

Estimates the amount of:
- body water (total body water),
- non-fat components of the body (fat-free mass),
- degree of body fat (fat mass)

Question 5

How do you use waist circumference, waist-to-hip ratios, and total body fat percentage to determine disease risk?

Answer 5

Waist (inches): Male > 40 in
Female > 35 in

Waist-to- Hip Ratio: Male > 1.0
Female > 0.8

Total Body Fat (%): Male > 25%
Female > 33%

Question 6

How many calories make up 1 lb of fat?

Answer 6

3,500 calories

Question 7

Name and describe the 3 components of energy expenditure.

Answer 7

3 components:
1. Basal (resting) metabolic rate (BMR):
- Rate Body expends energy to support vital functions (at rest), does not include voluntary activities.

2. Diet-induced thermogenesis (thermic effect of food):
   
   • Production of heat that occurs after eating.
   • Contributes to a rise in metabolic rate.
   • Supports ingestion, digestion, absorption, transport of food (nutrients)
   • Argument for frequent meals/ snacks to  thermic effect of food
3. Physical activity:
   
   • Most variable part of energy expenditure equation
   • Varies according to:
   • Body size
   • Type of activity
   • Volume/intensity of activity
   • Most effective way to increase “energy out.”

How does the body expend energy?
Basal Metabolism: 60%-65%
Thermic Effect of Food: 5%-10%
Physical Activity: 25%-35%

Question 8

What factors affect BMR (increase and decrease)?

Answer 8

BMR Increase:
- Caffeine
- Fever
- Growth
- Height
- High thyroid hormone
- Male gender
- Muscle mass
- Smoking
- Stress

BMR Decrease:
- Age
- Low thyroid hormone
- Reduced energy intake (fasting, starvation, low calorie diet)
- Sleep

Question 9

Describe the 2 causes of obesity related to genetics (as discussed in lecture notes).

Answer 9

Genetics – Ob gene:
- Ob gene: produces a hormone (leptin)
- Leptin tells the body to stop eating.
- Fat stores up: ↑ leptin (↓ appetite, ↑ energy expenditure)
- Fat stores down: ↓ leptin (↑ appetite, ↓ energy expenditure)
- Overweight? Defective Ob gene (↓ leptin production) or unresponsive to leptin

Genetics – Fat Cell Theory:
- Overweight child has ↑ number of fat cells
- Weight loss in adulthood only decreases SIZE of fat cells, not number of fat cells.
- Fat cells have enzyme Lipoprotein Lipase (LPL) which enables cells to store body fat.
- The more LPL, the more the body can pull triglycerides into fat cells for storage.

Environment:
- Availability of food
- Lack of opportunity for vigorous physical activity

Eating behavior:
- Hunger: programmed by heredity (physiological)
- Appetite: influenced by learned responses (psychological)