Obesity

Question 1

Weight Classifications

Answer 1

Individuals classified as obese or non-obese for evaluation of potential risk factors.

• BMI used as a proxy for body fat %
  
  • Does not take into account body composition
• Waist size also a risk factor
  
  • > 40 in for males
  • > 35 in for females
  • ↑ waist size in normal weight person also a marker for ↑ risk

Question 2

NHANES

Answer 2

Ongoing national survey of Americans.

Records various anthropometric, nutritional, and lab data.

Accessible for anyone to analyze by appropriate statistical/epidemiological methos.

Provided bases for numerous reports.

Question 3

Obesity & Overweight

Epidemiology

Answer 3

Overweight and obesity extremely common in the US and globally.

Problem worsening among both whites and blacks.

Women, especially black women, with highest rates of severe obesity.

Question 4

Health Risks

Associated with Obesity

Answer 4

• Cardiovascular disease and stroke
• Hypertension
• Some cancers (e.g., colon, breast)
• Type 2 diabetes
• Sleep apnea
• Osteoarthritis
• Fertility problems
• Non-alcoholic fatty liver disease
• Gout
• Incontinence

Question 5

Psychological Problems

Associated with Obesity

Answer 5

Includes:

• depression
• eating disorders
• low self-esteem

Physicians subject to bias against obese patients.

Question 6

All-cause Mortality

Answer 6

Significant ↑ in all-cause mortality as function of BMI.

Mortality risk highest for BMI <18.5 and > 30.

Due to atherosclerosis, DM, CKD, and some cancers.

BMI 25-29 (overweight) is not associated with ↑ death rates.

Do have ↑ risk of DM and kidney diseases.

Question 7

Metabolic Syndrome

Answer 7

Constellation of symptoms defined as 3 or more of the following:

1. Excessive waist size (>40 in. for men; >35 in. for women)
2. Elevated fasting glucose (>110 mg/dL; 70-100 mg/dL is normal)
3. Elevated serum triglycerides (>150 mg/dL; <150 mg/dL is normal)
4. Low HDL (<40 mg/dL; >60 mg/dL is a negative risk factor for CVD)
5. Hypertension (>130/85 mm Hg)

Patients meeting criteria are at ↑ risk for CAD and type 2 DM.

Linked to ↑ risk of obesity, non-ETOH fatty liver, CKD, PCOS.

Question 8

Causes of Obesity

Answer 8

Multifactorial Disease

1. Genetics
   
   • 9 loci involved in Mendellian forms of obesity
   • 58 loci contributing to polygenic obesity
2. Formula Feeding
   
   • purposed that infants fed formula during first 6 months are more likely to be obese at 24 months
   • may be publication bias
3. ↑ consumption / ↓ energy expenditure
   
   • sign. ↑ caloric consumption in US over past 40 years
     
     • ↓ fat
     • ↑ carbs
       
       • likely d/t fast food and sweetened drinks
     • protein constant

Question 9

Adipose Hormones

Answer 9

1. Leptin
   
   • reduces appetite
2. Adiponectin
   
   • reduces serum FFA
   • improves lipid profiles
   • ↑ insulin sensitivity
   • ↓ inflammation

As body weight ↑:

leptin ↑

adiponectin ↓

Question 10

Ghrelin

Answer 10

Hormone released by GI system.

Produced in the absence of food.

Increases appetite.

Question 11

Body Shape

Answer 11

Apple shape: increased fat deposition in the abdominal area.

Pear shape: increased fat deposition in the hips and thighs.

Apple shape at greater risk for Type 2 DM.

Waist reduction may be more important than weight reduction.

Question 12

Body Weight Set-Points

Answer 12

Most people w/ body weight set-point over short- to medium-term.

• Controlled by coordinated ∆ to caloric intake & energy expenditures.
• Stabilizes body weight and resists changes.
• Hormone influences appear to conspire against sustained changes in body weight set point.
• Body weight tends to increase with age.

Question 13

Diets

Answer 13

1. Weight loss should not exceed 10% over 6 months
2. Low calorie balanced diet key (800-1,500 Cal/day)
3. Resonable goals for weight loss essential
4. Behavioral strategies important
   
   • stress management
   • eating stimulus control
   • cognitive restructuring
   • social support
5. Adherence to any structured diet regardless of composition can be effective
   
   • ​various diets can achieve 3-6% reduction over 5 months
   • social support component may acheive greater compliance
6. Concerns over serum lipids w/ a high-fat, low-carb diet unfounded
7. Mediterranean & low carb diets better than low-fat diets for weight loss and lipid profiles
8. Smoking cessation does not rule out possibility of long-term weight control

Question 14

Weight-loss Drugs

Answer 14

Medication along with diet and lifestyle changes may be appropriate for BMI >30.

• Mechanisms:
  
  • appetite suppression
  • satiety enhancers
  • inhibitors of fat digestion

Ex. Qsyma

Phentermine (↓ appetite) and topiramate (↑ satiety)

Question 15

Exclusions from Weight Loss Therapy

Answer 15

Weight loss therapy is not appropriate in:

1. Pregnant or lactating women
2. Those with serious psychiatric disorders
3. Those with severe illnesses
   
   • caloric restriction might exacerbate illness

Question 16

Bariatric Surgery

Answer 16

Possible option for:

• severe obesity where less invasive methods have failed
  
  • BMI > 40
  • BMI > 35 with comorbidities
• those at high risk for obesity-associated morbidity or mortality

Patients s/p bariatric surgery at risk for PEU or vitamin deficiency.

Mainly vit B₁₂, folate, zinc, iron, copper, calcium, and vit D.

Swedish Obesity Study showed bariatric surgery can enable substantial and long-term weight loss.

Partially due ↓ Ghrelin production ⇒ ↓ feelings of hunger and food intake.

Question 17

Pediatric Obesity

Answer 17

• Assessed via growth charts
  
  • BMI for age at 95th %ile or greater ⇒ obese
  • BMI for age at 85th - 95th %ile ⇒ overweight
• On the rise with % obese 14-19% in 2008
• More likely to become obese adults

Question 18

Pediatric Metabolic Syndrome

Answer 18

Prevalence among 12-14 y/o is 22-44%.

No established definition but suggested parameters include:

1. Large waist size
2. Elevated fasting glucose
3. Elevated TGs
4. Low HDLs

Question 19

Pediatric Type 2 DM

Testing Guidelines

Answer 19

Overweight (>85th %ile) plus any 2 of the following:

• family history of Type 2 DM in 1st or 2nd degree relative
• are Native American, African American, Hispanic, or Asian/Pacific Islander
• signs of insulin resistance (e.g., acanthosis nigricans)

Question 20

Diabetic Ulcers

Nutritional Treatment

Answer 20

• Uncontrolled DM can result in an improverished body
  
  • due to various metabolic processes
    
    • inappropriate gluconeogenesis
    • decreased protein stores
  • dieting may exacerbate nutritional disturbances
• Glycation of basement membrane d/t excess BGL
  
  • contributes to microvascular atherosclerosis
  • poor circulation prevents adequate blood flow for healing
• Peripheral neuropathy hides severity of trauma
• Addition of Glucerna dramatically shortened healing time of diabetic foot ulcers
  
  • a nutritional formula used as Medical Nutrition Therapy in the frail elderly
  • contains high protein content
  • contains slowly-digested polysaccharides
    
    • blunts the glycemic response