Sleep deprivation (e.g., 3.5-5.5 hours per night) has been shown to be responsible for which of the following effects?

Sleep deprivation, particularly in the range of 3.5 to 5.5 hours per night, has significant physiological effects, one of which is a reduced resting metabolic rate. This occurs because inadequate sleep disrupts various hormones that regulate metabolism, such as cortisol, ghrelin, and leptin. When sleep is compromised, the body's ability to efficiently use energy is impaired, leading to a decrease in the basal metabolic rate (BMR). Lower BMR means that the body burns fewer calories at rest, which can contribute to weight gain and other metabolic issues over time.

Understanding the physiological consequences of sleep deprivation helps clarify why the other effects listed do not align with the typical outcomes of insufficient sleep. While enhanced mood regulation and heightened cognitive function are generally associated with adequate sleep, lack of sleep is more commonly linked to negative impacts on mood and cognitive performance. Additionally, sleep deprivation would not support increased muscle mass, as adequate rest is crucial for recovery and muscle synthesis. Thus, it is clear that reduced resting metabolic rate is a direct consequence of insufficient sleep.