There are many reasons we don't get enough sleep -- or enough good sleep. Jet lag, long work commutes, infants, gastric reflux, barking dogs, snoring spouses, hot flushes, alcohol consumption and stress are just some of the reasons we wake up so frequently. When any of these things happen, we don't go through all the critical stages of sleep or get out of bed before we have slept long enough.
According to the experts, the average person should sleep about seven to eight hours a night and during this time, go through the four stages of sleep. Stage I lasts about brief 10 minutes (it is said that if you awaken during this period you might deny you were asleep at all). Stage 2 is relatively long and accounts for about 50 percent of sleep time. Stage 3 is the phase when the body repairs and restores itself. Stage 4 is marked by REM (rapid eye movement) sleep that comes at the end of the sleep cycle. This is the stage when we tend to dream.
Spending the correct amount of time in these various sleep stages is a goal many of us rarely attain. Awakening several times during the night for whatever reasons changes the length of time spent in some of these sleep stages or may eliminate them altogether. Often we have to awaken before going through the last stage of sleep because work, family or being in another time zone necessitate getting up before the last cycle ends. Most of us are familiar with the mental and physical discomfort that comes from inadequate sleep, and we don't have to be told about the muddle headedness, digestive problems, headaches, and exhaustion that pursue us until we can crawl back into bed again.
For more than 15 million Americans disrupted or shortened sleep is a permanent way of life. These are individuals who work a nontraditional schedule. Either their work begins mid-afternoon and lasts until late evening or it begins around midnight and lasts until 6 or 7 a.m.
These workers may be invisible to us but the health consequences of working evening and nighttime shifts are all too visible to them. Studies on the health of people who work non-traditional hours show a high incidence of obesity, diabetes and the risk factors associated with cardiovascular disease such as elevated cholesterol levels and high blood pressure. Inadequate and disrupted sleep is a common complaint; they are often excessively sleepy but may have trouble falling and staying asleep during daylight hours.
Why should it be so hard to adjust to a new work schedule that requires being awake when one is normally asleep and asleep when one is usually getting up? The reason involves a clock like mechanism in our brain which keeps the cells of our body in rhythm with the light and darkness of the outside world. There is a daily or circadian rhythms to all our functions. For example our bodily temperature dips and peaks at specific times during the day and night, certain hormones also rise and fall with time of day and sleep is naturally initiated at night rather than in the morning. So when we force our bodies to sleep or be awake when the brain clock wants the opposite, the rhythm of our bodies is in conflict with the outside world. Eventually the brain clock adjusts to the new schedule or time zone which is why jet lag goes away. But when a shift worker has some days off or daytime commitments that cut into sleep time, this adjustment can be slowed down.
After sleepiness, weight gain is probably the most common side effect of shift work. As several of my weight-loss clients who worked afternoon or evening shifts told me: "You eat to wake up, you eat to stay awake, and you eat to sleep." And a transit policewoman added, "There is nothing to eat at 3 a.m. except doughnuts, pizza and Chinese food."
Weight gain doesn't have to be inevitable. After all we travel to new time zones for brief periods and even though we eat and sleep at new and uncomfortable hours, we can monitor our food choices and portion sizes so we don't come back five or more pounds heavier.
If food is brought from home, then the whole problem of what to eat and where to find it is avoided. The only adjustment is when to eat those meals and snacks. It is easiest to eat one meal before leaving for work and then have the main meal during the shift, perhaps three to four hours after it starts.
High-fat foods tend to make people feel tired regardless of when they are eaten so they should be avoided. Eating a snack around two hours before the end of the shift such as breakfast cereal, pretzels, popcorn, and some raisins or dried cranberries takes the edge off hunger and makes it easier to eat a light meal after the shift is over. The final meal should be mainly carbohydrate, like oatmeal with some banana or a baked potato with steamed vegetables. It is often easier to eat this at home, almost like a bedtime snack. The carbohydrate in the potato or oatmeal increases serotonin so it is easy to wind down before going to sleep.
The most important thing the shift worker can do to prevent weight gain is to get enough sleep. It is very hard to control eating because sleepiness seems to obliterate will power. And yet today, many shift workers are still unable to obtain enough sleep or sleep that goes through all the necessary stages. It is to be hoped that those people responsible for developing health initiatives to decrease obesity recognize this problem and are developing strategies to resolve it.
Follow Judith J. Wurtman, PhD on Twitter: www.twitter.com/stopmed_wt_gain