The obesity problem may not be what we usually think it is! University of Copenhagen Workshop I: Food for thought August 29, 2011 Thorkild I.A. Sørensen, MD, Dr Med Sci, Professor, Director Institute of Preventive Medicine Copenhagen University Hospital Copenhagen, Denmark 35,000 years old Fertility Goddess

Obesity reflects a surplus of energy Obesity must be due to a lasting positive energy balance (1st thermodynamic law). The difference between energy intake and expenditure is so tiny and variable that it cannot be precisely measured except by the eventual increase in amount of fat. What we need to know is what induced the lasting, tiny positive energy balance. That the obese eat more and move less is due to their obesity, and cannot be taken as its cause!

What induced the obesity epidemic? Useful to know because we then have a likely modifiable target to oppose. The emergence of the ’obesogenic society’ came after the take-off of the epidemic! Something has changed very early in life inducing increase in obesity among preschool children born since the early 1940’es.

What induced the obesity epidemic? Useful to know because we then have a likely modifiable target to oppose. The emergence of the ’obesogenic society’ came after the take-off of the epidemic! Something has changed very early in life inducing increase in obesity among preschool children born since the early 1940’es.

The obesity epidemic emerged in the school- boys much earlier than in the draftees The changes ocurred about 10 years later in the about 10-year-older young men. Year of measurement

What induced the obesity epidemic? Useful to know because we then have a likely modifiable target to oppose. The emergence of the ’obesogenic society’ came after the take-off of the epidemic! Something has changed very early in life inducing increase in obesity among preschool children born since the early 1940’es.

The trends coincides by year of birth The environmental changes driving the epidemic must operate around the time of birth – the individuals may become predisposed within the first years of life.

Why is obesity harmful? Entering adult life as obese is equal to heavy smoking in health damages and shortening of life expectation. The fat stored in cells is a very useful energy reserve and biologically innocent, but there are individual limits of expandability of the adipose depots. Exceeding these limits may be the reason why obesity appears harmful (lipotoxicity)

Kaplan Meier plots for the obese cohort (grey line) and the randomly selected cohort (black line)

Double cumulative hazard plot at corresponding ages of total mortality of the obese cohort versus the randomly selected cohort Total mortality: 2.05 ( )

Why is obesity harmful? Entering adult life as obese is equal to heavy smoking in health damages and shortening of life expectation. The fat stored in cells is a very useful energy reserve and biologically innocent, but there are individual limits of expandability of the adipose depots. Exceeding these limits may be the reason why obesity appears harmful (lipotoxicity)

Limits of expandability Morbidly obese individuals without any metabolic disturbances Very slim individuals without adipose tissue (lipodystrophy) with severe metabolic disturbances

Why is obesity harmful? Entering adult life as obese is equal to heavy smoking in health damages and shortening of life expectation. The fat stored in cells is a very useful energy reserve and biologically innocent, but there are individual limits of expandability of the adipose depots. Exceeding these limits may be the reason why obesity appears harmful (lipotoxicity)

Incidence of diabetes: RR 4.92 ( )

Inspiration is needed! We do not know what started the obesity epidemic except that it was something very early in life! Obesity may reflect an appropriate defense against the dangers of its causes! The epidemic may have saved us from even worse health consequences, now seen in Asia! What is the role of type and amount of food!?