Studies have shown that sleep loss impacts glucose regulation and metabolism, key processes that prevent diabetes and weight changes.

Diabetes

In a lab study, 11 healthy adults went through two different conditions – sleep deprivation (4hrs sleep /night, for 5 nights) or full sleep. On day 6, their glucose tolerance was measure – glucose tolerance test involves an injection of glucose, then measures how efficient the body is at removing it.

• Glucose tolerance (efficiency/speed of clearing glucose from blood) was impaired by over 40% after sleep loss.
• These levels are similar to someone that a doctor would classify as being pre diabetic.

<aside> ⏩ Sleep loss increases glucose levels.

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Weight Gain

If you’re dieting and not getting enough sleep then 70% of the weight you lose will be muscle not fat. Looking across the past 60 years, there has been a sharp rise in obesity. When comparing it to the self-reported sleep hour over each year.

There is a correlation between obesity and sleep loss.

<aside> 💉 Sleep loss increase obesity rates

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Appetite

In another study, healthy male adults went through two different conditions – sleep deprived (4hrs sleep /night, 2 nights) or full sleep. On day 3, their leptin (inhbits appetite) and g*hrelin (increases appetite)* levels were measured, together with their own subjective ratings of how hungry they felt, and what they were hungry for. After, they were taken to a buffet to see how much they ate and what they ate.

They found that leptin (don't eat) decreases and ghrelin (eat) increases under sleep loss, thus those who slept less at 800-1000 more calories, in particular for carbs.

<aside> 💉 Sleep loss increase appetite for carbs

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