Sleep needs vary across ages and are especially impacted by lifestyle and health. Researchers cannot pinpoint an exact amount of sleep need by people at different ages. However, sleep requirements vary from person to person even in the same age group.
There is a big difference between the amount of sleep one can get by on and the amount one needs to function optimally. For instance, if one is able to operate on six or seven hours of sleep doesn’t mean one wouldn’t feel a lot better and get more done if one spends an extra hour or two in bed.
The new recommendations of the daily sleep requirements for adults by the National Sleep Foundation include:
- Younger adults (18-25) – Sleep range is 7-9 hours
- Adults (26-64) – Sleep range is 7-9 hours
- Older adults (65+) – Sleep range is 7-8 hours
New born babies, infants, toddlers, children and teenagers have more daily requirements of sleep, which vary depending on their age.
Sleep deprivation occurs when an individual gets less sleep than they need to be attentive and alert. People vary in how little sleep is needed to be considered sleep-deprived. Some people such as older adults seem to be more resistant to the effects of sleep deprivation, while others, especially children and young adults, are more vulnerable.
Science has linked sleep deprivation with all kinds of health problems, from weight gain to a weakened immune system. Observational studies also suggest a link between sleep deprivation and obesity. Similar patterns have also been found in children and adolescents.
The following mechanisms have been found to underlie the link between sleep deprivation and weight gain –
Increase in ghrelin level –
In a research published in the Journal of Sleep Research in Sep. 2008, it has been found that a single night of sleep deprivation increases ghrelin levels and feelings of hunger in normal weight healthy men, whereas morning serum leptin concentrations remain unaffected. Thus, the results provide further evidence for a disturbing influence of sleep loss on endocrine regulation of energy homeostasis, which in the long run may result in weight gain and obesity.
Ghrelin is a hormone produced in the gut and is often termed the hunger hormone. It sends a signal to the brain to feel hungry. Therefore, it plays a key role in regulating calorie intake and body fat levels.
Interference in carbohydrate metabolism –
Sleep deprivation interferes with the body’s ability to metabolize carbohydrates and causes high blood levels of glucose, which leads to higher insulin levels and greater body-fat storage. In one experiment, scientists disrupted participants sleep just enough to keep them from entering deep sleep but not enough to fully wake them. After these nights of deep-sleep deprivation, the subjects’ insulin sensitivity and glucose tolerance went down by 25 percent.
Reduction in growth hormone –
Sleep deprivation reduces levels of growth hormone – a protein that helps regulate the body’s proportions of fat and muscle. Experts estimate that as much as 75 percent of human growth hormone is released during sleep. Deep sleep is the most restorative all stages of sleep. During this stage of sleep, growth hormone is released and works to restore and rebuild our body and muscles from the stresses of the day.
Increase in cravings for high-calorie junk food –
Sleep deprivation even for one night creates pronounced changes in the way our brain responds to high-calorie junk foods. On days, when people don’t have proper sleep, fattening foods like potato chips and sweets stimulates stronger responses in a part of the brain that helps govern the motivation to eat. But at the same time, they experience a sharp reduction in activity in the frontal cortex, a higher-level part of the brain, where consequences are weighed and rational decisions are made.
Increase in cortisol –
Researchers have found that sleep deprivation increases the level of cortisol hormone and other markers of inflammation.
Decrease in resting metabolic rate –
There is evidence indicating that sleep deprivation may lower the resting metabolic rate of the body. It is the number of calories our body burns when we’re completely at rest. It’s affected by age, weight, height, sex and muscle mass. This needs further validation but one contributing factor seems to be that poor sleep may cause muscle loss.
The bottom line –
Besides, eating right and exercising regularly, getting quality sleep is an important part of weight maintenance. Therefore, establishing healthy sleep habits can help our body maintain a healthy weight.