Right amount of sleep is around 10pm-6am. Summer you need less than winter. Physical repair 10-2 and mental/emotional etc 2-6am. Timing IS important.

Sleep is a big factor in health of course and it also is in fat loss.

Fat is huge in health-the amounts differ for each person of course..

Example-stress hormones, like cortisol, are made from fat(basically). An over stressed body, be it poor food choices/amounts/quality/ratios, mental/emotional, financial, exercise, thermal, or a gun to your head etc etc all stimulate the sympathetic nervous system and you have an imbalance in cortisol.

If you are over stressed and eat a low fat diet guess where the material comes to make cortisol? Other hormones (fight or flight takes priority). So your repair hormones suffer, sex hormones suffer etc etc etc

Fat is huge in health including saturated fat. The quality and quantity is important of course and you can certainly have too much of a good thing.

Fat stores toxins (in humans too-some fat people can't loose weight cause if they did it would cause too much damage-they need to get healthy first). So poor quality fat-well you get lots of toxins.