In the last module, we took a slight detour away from topics that are more self-evidently central to nutritional study to discuss sleep. While sleep may not be as intrinsically linked to nutrition as other aspects of this course, we hope that you now appreciate that sleep has a direct impact on your overall health and wellbeing; and also that it can have an indirect impact on your weight management (due to its influence over the hormonal drivers towards appetite regulation). You should now understand the manner in which sleep restriction impairs cognition and therefore decision making ability. In module 7 you learned:
- Sleep is an active state caused by your brain rather than something which ‘happens to it’ due to simply becoming periodically fatigued
- Sleep is not a homogenous state, but something made up of 4 different stages – non-REM stages 1-3 and REM sleep. You cycle through these throughout the night, and each stage has unique properties and benefits
- Sleep is mediated by both the circadian rhythm which is governed by the suprachiasmatic nuclei, and the homeostat pathway which is governed by adenosine metabolism in the brain
- Sleep restriction can result in impaired reaction time, cognitive function, hormone secretion, immune function and subjective mood, but can also influence weight management owing to the effects both cause to endocrine drivers of appetite and conscious willpower
- There are a number of ways in which sleep can be improved, from altering the sleep environment to paying closer attention to your sleep hygiene