Lecture 1: Deconstructing Obesity
by Jeffrey M. Friedman, M.D., Ph.D.
Play Lecture One in Full
Introduction by HHMI President Dr. Thomas Cech
Introductory interview with Dr. Jeffrey Friedman
Understanding human diversity through science
People have opinions about what causes obesity
Obesity is associated with many diseases
Definition of obesity and the body mass index (BMI)
Animation: BMI and body shape
Limitations of BMI
What causes obesity?
Is the lack of willpower the main cause of obesity?
Obesity as a result of energy input/output imbalance
Eating is a basic biological drive and can overwhelm willpower
The role of environment as a cause of obesity may be exaggerated
Q&A: Why is there a difference in obesity between the U.S. and Europe?
Q&A: Is obesity linked to depression or other emotional states?
Q&A: Are there racial differences in the tendency to be obese?
Adoption and twin studies show that obesity is highly heritable
A genetic example of obesity: Leptin deficiency
Genetically engineered leptin-deficient mouse
Leptin, a hormone secreted by fat, influences appetite
Animation: Leptin feedback-control system
How leptin deficiency causes obesity and leptin replacement cures it
In most obese people, leptin sensitivity is reduced
Only a subset of obese people responds to leptin therapy
Biology is the main cause of obesity
Q&A: Are there other hormones that control weight?
Q&A: Is there a connection between leptin and age?
Q&A: Have you thought about marketing leptin injections?
Closing remarks by HHMI President Dr. Thomas Cech