obesity

Question 1

obesity Definition:

Answer 1

• Imbalance: Energy intake > energy expenditure.

* BUT…….obesity is complex, and there are metabolic differences among people in their tendency to gain weight.

Question 2

How do we identify overweight and obesity?

Answer 2

• -BMI (weight relation to height)

* Waist Circumference (visceral fat- around the abdominal organs which is more highly links to causing cronic deseases)

Question 3

Prevalence

Answer 3

-WHO - epidemic globally
– Prevalence
– Link with risk for chronic diseases
– Now developing countries affected too.

Question 4

Potential Health Risks of Overweight/Obesity? [Box 12.6 – Please review it]

Answer 4

• What are 2 big chronic diseases?
  1. cardiovascular disease
  2. diabetes

Question 5

Canadian Statistics (Statistics Canada) :

Answer 5

• 62% of Canadian adults aged 18-79 were overweight or obese.
• 31% of youth aged 5-17 years were overweight or obese.

Question 6

Etiology of Obesity

Known causes of obesity and overweight explain <1% of cases of obesity.

Answer 6

Some important examples: See Table 12.4

a) Genetic syndromes-eg. Prader-Willi (hypothalamic problem- appetite)
b) Endocrine – e.g. Cushing’s syndrome (cortisol excess- appetite); e.g. 2 hypothyroidism
c) Hypothalamic dysfunction-e.g. tumours ( appetite)
d) Medications-e.g. glucocorticoids; e.g.2 many psychiatric medications (Table 11.3); e.g.3 insulin, thiazolidinediones, sulfonylureas to treat diabetes.

Question 7

Etiology for the other >99% of cases of obesity:

Answer 7

-Complex?
-Familial tendency toward obesity is high.
-occuring in or affecting more family members tha expected by chance
If both parents obese: child has at least an 80% chance.
Includes genetic factors X environmental factors
X= INTERACTING WITH

Question 8

-The early studies aiming to dissect out the genetic influence were based on studying:

Answer 8

a) individuals in the family
b) pairs of twins,
body weight and adiposity of monozygotic twins closer than those of dizygotic twins
c) adopted children in relation to their biological and adoptive parents.
BMI of adoptees (as adults) correlated strongly with that of biological parents, but not as well with that of adoptive parents.

Question 9

Current studies focus on investigating “obesity genes”.
• Complicating Factor: Obesity is not inherited in families in a predictable manner like in some other diseases…….Because the genetic susceptibility is polygenic.

• Examples:

1. Leptin (e.g of gene regulating food intake]
2. Uncoupling proteins (e.g of genes involved in regulation of RMR)

•However, we know that environment is also extremely important.

Answer 9

l

Question 10

Describe the roles of environmental factors: “The Obesogenic Environment”

Answer 10

Boxes 12.7, 12.8 - text
Sedentary lifestyles
Fear of walking or bikeing
More technologies, growth in fast food industry, larger potion, more convinience foods available, aggressive marketing, PE class are receiving less funding, lack of sidewalks, automated work place, labor saving machinery for household chores