Sleep needs vary by age and are especially affected by lifestyle and health. Researchers can’t pinpoint the exact amount of sleep that people of different ages need. 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 and the amount one needs to function optimally. For example, if you can operate on six or seven hours of sleep, that doesn’t mean you won’t feel much better and get more done if you spend an extra hour or two in bed.

New recommendations for daily sleep requirements for adults from the National Sleep Foundation include:

• Young 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 to 8 hours

Newborns, infants, toddlers, children, and adolescents have increased daily sleep needs, which vary by age.

Sleep deprivation occurs when an individual sleeps less than they need to be attentive and alert. People vary in the amount of sleep needed to be considered sleep deprived. Some people, such as older adults, appear to be more resistant to the effects of sleep deprivation, while others, especially children and young adults, are more vulnerable.

Science has linked lack of sleep to 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:

Increased level of ghrelin –

In research published in the Journal of Sleep Research in September. 2008, a single night of sleep deprivation was found to increase ghrelin levels and feelings of hunger in healthy, normal-weight men, while morning serum leptin concentrations are unaffected. Thus, the results provide additional evidence for a perturbing influence of sleep loss on the endocrine regulation of energy homeostasis, which may ultimately result in weight gain and obesity.

Ghrelin is a hormone produced in the gut and is often called 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 –

Lack of sleep interferes with the body’s ability to metabolize carbohydrates and causes high blood glucose levels, which leads to higher insulin levels and increased body fat storage. In one experiment, scientists interrupted participants’ sleep just enough to prevent them from going into deep sleep, but not enough to wake them up completely. After these nights of deep sleep deprivation, the subjects’ insulin sensitivity and glucose tolerance were reduced by 25 percent.

Growth hormone reduction –

Sleep deprivation reduces levels of growth hormone, a protein that helps regulate the proportions of fat and muscle in the body. Experts estimate that up to 75 percent of human growth hormone is released during sleep. Deep sleep is the most restful of all the stages of sleep. During this stage of sleep, growth hormone is released and works to restore and rebuild our body and muscles from the stress of the day.

Increased cravings for high calorie junk food –

Sleep deprivation, even for one night, creates pronounced changes in the way our brains respond to high-calorie junk food. On days when people don’t get enough sleep, fattening foods like chips and candy stimulate stronger responses in a part of the brain that helps control 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.

Cortisol increased –

Researchers have found that sleep deprivation increases the level of the hormone cortisol and other markers of inflammation.

Decreased resting metabolic rate –

There is evidence indicating that sleep deprivation can decrease the body’s resting metabolic rate. It is the amount of calories that our body burns when we are at complete rest. It is affected by age, weight, height, gender, and muscle mass. This needs further validation, but a contributing factor appears to be that lack of sleep can cause muscle loss.

The bottom line –

Also, eating well and exercising regularly and sleeping well is an important part of weight maintenance. Therefore, establishing healthy sleep habits can help our bodies maintain a healthy weight.