Sleep needs vary by age and are especially affected by lifestyle and health. Researchers cannot determine 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 you can get and the amount you need to function optimally. For example, if one is able to operate on six or seven hours of sleep it does not mean that one does not feel much better and get more done if one or two more hours are spent in bed.

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

• Younger adults (18-25): sleep range is 7-9 hours
• Adults (26-64): sleep range is 7-9 hours
• Seniors (65+): sleep range is 7-8 hours

Newborn babies, infants, toddlers, children, and teens have more daily needs for sleep, which vary by age.

Sleep deprivation occurs when an individual sleeps less than is necessary to be attentive and alert. People vary in how little sleep it takes 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 poor 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 lack of sleep and weight gain:

Increased level of ghrelin –

In research published in the Journal of Sleep Research on Sept. In 2008, a single night of sleep deprivation was found to increase ghrelin levels and feelings of hunger in healthy men of normal weight, while morning serum leptin concentrations are not affected. Therefore, the results provide additional evidence of a disturbing influence of sleep loss on endocrine regulation of energy homeostasis, which in the long term can result in weight gain and obesity.

Ghrelin is a hormone produced in the intestine and is often called the hunger hormone. It sends a signal to the brain to make you feel hungry. Therefore, it plays a key role in regulating calorie intake and body fat levels.

Interference with 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 storage of body fat. In one experiment, scientists interrupted participants’ sleep long enough to prevent them from entering deep sleep, but not enough to fully wake them up. After these nights of deep sleep deprivation, the subjects’ insulin sensitivity and glucose tolerance decreased by 25 percent.

Growth hormone reduction –

Lack of sleep reduces levels of growth hormone, a protein that helps regulate the body’s fat-to-muscle ratios. Experts estimate that up to 75 percent of human growth hormone is released during sleep. Deep sleep is the most restful of all stages of sleep. During this stage of sleep, growth hormone is released and works to restore and rebuild our bodies and muscles from the stresses of the day.

Increased cravings for high calorie junk food.

Lack of sleep, even for one night, creates pronounced changes in the way our brain responds to high-calorie junk food. On days when people don’t get enough sleep, fattening foods like potato 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.

Increased cortisol –

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

Decreased resting metabolic rate –

There is evidence that a lack of sleep can lower the body’s resting metabolic rate. It is the amount of calories our body burns when we are completely at 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 wasting.

The bottom line –

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