Mr. Stenberg, thank you for your response. What you presented makes good sense.
However, I wish to push the explanation back just a step. Testosterone reduces
melatonin, which produces sleep. Melatonin suppresses leptin. Therefore,
testosterone reduces leptin itself and reduces melatonin which reduces leptin.
Since leptin reduces appetite, this overall reduction in leptin increases
appetite and obesity. (I looked at Carskadon's work; thank you for the
reference. Dr. Carskadon's is a good body of work which does, as you noted,
indicate that children are sleeping less.)
As a biologist this makes sense to me. You see, I suggest the "secular trend,"
the increase in size and earlier puberty of children, is actually an increase in
the percentage of individuals of higher testosterone within the population.
Some say the trend is due to increased caloric intake; increased calories only
accelerates reproduction and, therefore, the increase in individuals of higher
testosterone. As stated above, an increase in percentage of individuals of
increased testosterone should also produce an increase in the percentage of
individuals who sleep less and eat more. (Maybe the definition of the secular
trend should also include reduced sleep and increased appetite in children,
among other things.) This makes good sense, biologically. Increased sexuality
and reproduction should be coincidental with less sleep and more eating.
Testosterone happens to produce all of these simultaneously. There should be an
evolutionary advantage in higher testosterone where there are abundant calories.
Our children are reaching puberty earlier, sleeping less, and eating more;
biologists know this as "feed and breed."
Again, I suggest individuals of higher testosterone are increasing in percentage
in this population and we are seeing numerous "side effects" of this phenomenon.
These related phenomena include increasing appetites and obesity as these are
also increasing in percentage within this population.
James Michael Howard
On 16 Oct 2003 08:42:17 GMT, "Dag Stenberg"
<dag.stenberg at nospam.helsinki.fi.invalid> wrote:
>James Michael Howard <jmhoward at arkansas.net> wrote:
>> Testosterone reduces leptin. Leptin reduces appetite. Therefore, children of
>> higher testosterone have less appetite suppression. It is my hypothesis that
>> the percentage of individuals of higher testosterone is increasing. Therefore,
>> overeating is increasing. This accounts for the obesity "epidemic" in the
>>The population sleeps less and sleep onset times have become delayed
>during the last 10 years. This afflicts younger and younger age
>groups. Daytime sleepiness in schools has increased, especially in
>puberty. There is evidence for this (for ref., see Carskadon M et al., several
>studies). Because of insufficient sleep, sleep debt accumulates during the
>week, and people sleep off part of the accumulated sleep debt during
>weekends. Sleep debt reduces leptin. Leptin reduces appetite. Therefore,
>children and adults getting insufficient sleep have less appetite
>suppression. It has been pointed out that sleep loss increases craving for
>fat, carbohydrate and salty food - in a word, junk food. Because of the
>epidemically increased sleep deficit, overeating is increasing. This
>accounts for the obesity "epidemic" in the U.S.A. and the rest of the