Carbohydrates are synthesized into sugars (glycogen), which are then stored in the liver during its “night” assimilatory phase beginning at 3 p.m. and peaking at 3 a.m. These stored sugars are converted to blood glucose during the daytime for the activities of consciousness beginning at 3 a.m., through the catabolic (breaking down) influence of the gall bladder in the liver until about 3 p.m. Here, we can see the importance of going to sleep early: 6:30-8:00 p.m. for children and 9-10:00 p.m. for adults. Staying up late causes the liver to reverse its storing-up activity intended for the next day and to instead begin converting glycogen to glucose for energy, thus we get a “second wind” (especially children). This explains the worn-out feeling the next morning and the daylong physiologic struggle to keep up. (Johnson) http://www.waldorflibrary.org/images/stories/Journal_Articles/GW43gromicko.pdf
I have copied this article here for posterity’s sake, should the author’s original site ever go down.
Susan R. Johnson MD, FAAP, 2/3/2000
I still struggle getting my almost 7 year old son asleep by 8:00. It seems there is a magic window. If we eat by 5:00 and I start slowing down his activities by 6:oo then there is a good chance that he will fall to sleep soon after reading stories at 7:30. If I don’t have dinner ready until 6:00 or 7:00 and slow down doesn’t begin until 8:00 or 8:30 then my son seems to get a second wind that keeps him awake and active til 10:00 or 10:30 at night. The next day is difficult for him. It is hard for him to get up, eat breakfast, and get to school on time. He is tired and more irritable the entire day. What is happening?
If you go to see an anthroposophical physician with these complaints, then chances are your child will end up with a remedy for the liver. Often Hepatodoron (made from the leaves of the vine, Vitus vinifera, and the wild strawberry, Fragaria vesca) is given. It seems that the liver is involved in our ability to have a good nights sleep. It regulates our energy level for the next day and relates to our overall feelings of contentment or depression. The liver follows the cycle of the sun. Around 6:00 in the evening it wants to go to sleep and starts to store up the sugars (glycogen) to be used for the next day. It doesn’t want to process any big meals (especially ones high in protein or fat after 3 pm).
When our children (and us) stay up late at night we affect the liver’s metabolism. It can no longer simply store sugar. Our body, by being awake and active, needs sugar in the blood stream and so we force the liver to reverse its process and breakdown glycogen to provide this sugar. We get a second wind, a burst of sugar in our blood stream, and yet we are really depleting our energy for the next day. Our liver can’t store up the glycogen it needs for the next day and so the next day we have a liver that is depleted of glycogen. Our body THEN requires us to release stress hormones from our adrenal glands to keep us functioning. These hormones act to provide more sugar in the blood, but they also accelerate our heart rate, increase our blood pressure, and suppress our immunity (we get colds more easily). You can tell when stress hormones are acting since one also develops cold hands and cold feet during the day from the vasoconstriction of the blood vessels to the hands and feet.
The combination of stress hormones and too little glycogen in the liver makes us develop a craving for sugar. When we eat something really sweet (like candy or cookies), especially on an empty stomach, the excess load of sugar overstimulates our pancreas to produce too much of another hormone, insulin. Too much insulin causes our cells to take up or absorb too much sugar so that there isn’t much sugar left in our blood. We become hypoglycemic with a low blood sugar. We feel tired, irritable and lightheaded and, for children, their body movements become more impulsive and overactive (less purposeful). Being hypoglycemic makes us crave sugar again and the whole process repeats itself throughout the entire day.
Some children and adults are more sensitive to these changes than others. Their pancreas may release more insulin in response to sugar. Some children and adults release more stress hormones in response to sleep deprivation, but this physiologic response occurs in all of us. For children that are already very active and have difficulties paying attention in school, going to bed early and cutting down on sugar really can help the child and family function better.
They say that any sleep you get before midnight is restorative and counts for double, and therefore it is far better to go to bed early (7:00 to 8:00 for a young school-age child and 9:00 to 10:00 for an adult) and wake up early to get your work done. Maybe this is the truth in that saying by Benjamin Franklin: Early to bed, early to rise, makes (one) healthy, wealthy, and wise.
YouandYourChildsHealth.org is a library of health information about raising children and creating a healthier family life. This Living Book also contains personal stories about the joys and triumphs, as well as the struggles and challenges, we face as parents. It is made freely available as a public service.
© Susan R. Johnson, M.D., F.A.A.P.