Weight, light and body clocks – timing dining right (10/19/10)
When You East is as Important as What
The conclusion – “When you eat could be as important as what you eat,” is virtually the same sentence I wrote ten years ago. The article is from this week’s Economist, with its excellent science section, entitled “Does light make you fat?” The real question – what took you so long to figure this out?
Past is Prologue
Fritz Halberg gave the same meal to American military recruits – one meal, at different times of day. The soldiers who ate the 2000 calorie repast in the morning lost weight; those who had it for lunch showed no weight change; those who ate it for supper gained weight. The date of the study – 1972.
It’s also been known for decades that shiftworkers gain more weight than non-shiftworkers. They have far more GI complaints, as well.
Animal studies produce the same results. The most recent one, in Proceedings of the National Academy of Sciences, was discussed in this space on October 13 –“Don’t Eat at Night.” Mice who were kept in dim light during their night, when they were normally active, gained 50% more weight than those living through the normal light-dark cycle. Much of the weight they gained appeared when they ate during the daytime – when they would normally sleep.
Night eating humans also gain a lot of weight. And they develop higher lipid and sugar levels than when eating during the day.
So why are these elements of human design so hard for people to grasp?
- Body Clocks and Human Design
In 1959 Fritz Halberg gave poison to a group of animals. Virtually all of them died. He then gave the same amount of poison to the same type of animal, but 12 hours later on the clock than the first group. All survived.
Chronobiology – time’s effect on biology – has been established for more than 50 years. Yet people still can’t seem to understand that they change, powerfully but predictably, throughout the day.
The problem may be the machine model of health and disease.
The Machine Model of Disease
You pick up the standard line early in your school years – the body is a very complicated machine, but it’s a machine. It stays the same through the magical process of homeostasis – getting all the parts to work well together in physiologic harmony. When everything is oiled and well greased, it all goes down well – and you’re well. A part breaks down, and you get sick.
What’s wrong with the model? Pretty much everything.
First, most of you gets replaced in hours to weeks. The system is remaking and recreating itself all the time, quickly and differently.
Second, you are different from minute to minute. The 24 hour day-night cycle is a design element of pretty much all terrestrial life, and you do things differently on the hour. That’s why sports records are set in the early evening, when your body is more powerful and accurate.
Third, you constantly learn. Your system is not only changing, but changing with age, with environment, and with everything your body has responded to. That learning can and eventually does radically change your body’s rebuild.
So you’re never the same from day to day. Your brain is different. Your gut is different. Your skin is different. Even your memories are different.
Yet this level and pace of change may be so overwhelming that it’s not dealt with at all – we refuse to see it.
Which is why teenagers think they don’t need to sleep. Why CEOs proudly announce how little they rest. Why work becomes a 24-7 fest – why should 4 AM be different from 4 PM?
Because it is. Humans are designed for different activities at different times of day. Like eating more in the morning, when your baseline insulin levels are higher and you metabolize food more effectively, and less at night, when you will gain more weight, have higher lipid levels, and not sleep as well.
It’s not homeostasis that matters, but how you grow yourself and change – how effective your rebuild is. That’s what helps determine whether you get fatter or thinner, smaller or smarter. And much of that rebuild is under your control.
But first you have to recognize that rebuilding, reengineering, and reinventing is what you and your body do superlatively well. Timing it right makes it work.
Rest, sleep, Sarasota Sleep Doctor, well-being, regeneration, longevity, body clocks, insomnia, sleep disorders, the rest doctor, matthew edlund, the power of rest, the body clock, psychology today, huffington post, redbook, longboat key news