Most individuals need 7-9 hours of sleep a day for optimal functioning. Those who sleep less than 5 hours are at greater risk for developing insulin resistance (where your body needs to secrete more insulin to keep your blood sugars normal) and diabetes. Scientists have also shown that when individuals sleep <5 hours they make different choices regarding types of food and are more likely to choose sweets and foods with more calories. This change in food preference seems to be related to changes in the brain hormones leptin and ghrelin that affect eating behavior.
Also, it is important for health to maintain a normal circadian rhythm (day-night cycle), meaning you generally sleep when it is dark and wake when it is light. Night-shift workers are at risk for weight gain. Staying up in the midnight hour puts us at risk for increased weight gain by altering our circadian rhythm, important for the hormones insulin and cortisol to work correctly. Inadequate sleep also leads to increase in body inflammation that increases risk for diabetes, heart disease and even may change our eating behavior by affecting the brain. Staying up late is often associated with grazing and eating when not hungry. Just going to sleep may save you 300-600 calories/day.
Obstructive sleep apnea (a condition in which the body stops breathing temporarily during sleep) is often found in persons who are overweight. Symptoms include day-time sleepiness, decrease in memory and focus, snoring, gasping at night, morning headaches, feeling irritable, having a neck size > 17 inches (male) or >15 inches (female); being >30 pounds overweight; some individuals don’t really notice a difference until they get treatment and they realize that they have been feeling poorly for quite some time. Untreated sleep apnea can interfere with a person’s ability to lose weight as well as increase risk for cardiac rhythm problems like atrial fibrillation, hypertension, insulin resistance, pre-diabetes and diabetes. Many people don’t like the idea of wearing a mask to sleep at night but there are many different options for treatment.
Habits, aging, working night shift, pain, medicines and other sleep/medical conditions can also disrupt sleep. Speak with your doctor about optimizing your sleep.