obesity bio medical perspective

public health

obesity is a common chronic disease of adults and children

it is an ideal case study of 6 different public health perspectives

National and international Overweight and Obesity efforts focus on ____, ____, and ____ strategies to make healthy eating and active living accessible and affordable

biomedical, policy, environmental

stigma = co-occurrence of labeling, stereotyping, separation, status loss, and discrimination in a context in which power is exercised

know the difference between a stigma and discrimination

(bio medical perspective)

high amount of body fat relative to lean body mass

obesity

individuals: >30% body fat in females , >25% body fat in males

populations: body mass index (BMI) > 30

BMI

Measure of body density

BMI= kilograms / meters squared

As Asian populations develop negative health consequences at a lower BMI than Western Populations, some nations have redefined obesity

ex: The Japanese have defined obesity as any BMI greater than 25, while China defines it as any BMI of greater than 28.

visceral fat accumulation is related to many diseases

Hunger signal

Ghrelin

short term satiety signals

• nerves in the stomach

• hormones released from intestine

• hormones released from pancreas

• nutrients sensed by brain

Long term satiety signal

Leptin

why do humans have propensity to gain weight ?

• genetics, thrifty genes

• propensity for calorically dense foods

• the food environment

• changing energy expenditure patterns

obesity relations

underweight

<18.5

normal

18.5-24.9

overweight

25-29.9

obese

>30.0

regulation of energy intake

First law of Thermodynamics: “energy is neither created nor destroyed”

regulation of energy intake

Energy intake = energy expenditure + Change in body stores of energy

regulation of energy intake

Energy balance = energy intake - energy expenditure = 0

regulation of energy intake

One view of weight gain, then, is that more calories in versus calories out leads to weight gain