Download Physiology of Hunger

Physiology of Hunger
Glucose= blood sugar
 Pancreas produces insulin / breaks down glucose
(converts some to stored fat)
 Stomach, liver, intestines: signal brain as to
glucose level

Hypothalamus
Part of Limbic System
 Helps govern endocrine system (regulates
pituitary gland)
 Linked to emotion
 Drives: eating, drinking, body temp.
 Monitors levels of body’s appetite
hormones

Lateral Hypothalamus
Stimulates hunger
 rat research

 Stimulate:
Continuous eating to obesity
 Destroy: Starving would not eat
Lower-mid hypothalamus (Ventromedial)
Depresses hunger
 Stimulation = stop eating
 Destroy it = obesity (no brakes)

Hormones / Chemicals and Hunger…

Ghrelin: hormone secreted by empty
stomach (arouses hunger)
 Gastric
bypass surgery = less ghrelin
Orexin: stimulates hunger (activated by low
glucose)
 Leptin: chemical secreted by fat cells

 suppresses
hunger
PYY: Digestive hormone / suppresses
hunger
 Research to address obesity

Theories on Hunger and Body Weight

Set Point: (weight thermostat)
 Body
adjusts to changes in food intake to
maintain homeostasis (has a general, preset
tendancy to maintain a certain body weight)
 Less food = rise in hunger , fall in energy
 9 month study: ½ food intake, 25% set point
 Set point outdated / “settling point”

Basal metabolic rate: energy expenditure
at rest (metabolism)
Hunger Motivation
Eating Disorders
Anorexia Nervosa
 Obsession with losing weight (15% or more)
 Starts with weight-lost diet
 Negative self-body image / perfectionist
standards
 Usually adolescents
 Mothers who focus on own weight
 Competitive, high-achieving families
 9 of 10: female
 Genetic and cultural theories
Eating Disorders

Bulimia Nervosa

Binge-Purge
Overeating, compensatory vomiting, laxative use,
fasting, extreme exercise
Dieter breaks diet restrictions…
weight fluctuations within or above normal ranges
(easy to hide)
Often sweet, high fat foods
Depression, anxiety
½ of anorexia victims have bulimia symptoms
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Anorexia, Bulimia
The Ideal of Slenderness
Distorting Reality
Obesity
Obesity