You check off the items on the list to help you get a night of restful sleep -- a good bedtime hour, comfortable night wear, soothing lighting, the right room temperature.
You have not had a stressful day and do not feel over-tired. You lie there and wait for sleep to take over, except that it eludes you half an hour after you have tucked in.
You are almost certain that what will follow is a night of tossing and turning.
Is there something amiss? There may well be.
We already know that certain foods or beverages like coffee, tea, and alcohol, or eating a large meal should be avoided before bedtime to gain a better sleep experience.
Researchers at School of Exercise and Sport Science, Faculty of Health Sciences, The University of Sydney found that eating certain high glycemic index carbohydrates helped shorten the time for the onset of sleep.
So what is the glycemic index (GI)?
GI is a numerical scale which tells us how quickly and to what degree a particular food can elevate our blood glucose/sugar level. The lower a food's GI or glycemic load, the less it affects blood sugar and insulin levels. (1)
In other words, the higher GI foods suggested by researchers to crash the onset time to sleep are the ones that will have a significant effect on your blood sugar and insulin levels at a relatively short period of time.
The study observed 12 healthy adult volunteers between the ages 18 and 35, to check the role of carbohydrate in the induction of sleep, and the effect of GI and mealtimes on sleep of the participants.
The volunteers were randomly divided into sub-groups and were administered high and low GI-based carbohydrate foods, four hours prior to bedtime to test for quality of sleep.
The participants derived most of their energy from carbohydrates and only 8 percent from proteins and 1.6 percent from fats.
They were offered meals of two types of rice four hours prior to sleep. On other occasions they would be given a high GI meal an hour before going to bed. The participants underwent a familiarization night, followed by three test nights in random order, one week apart. (2)