Sleep isn’t one thing. It’s four. Quantity. Quality. Regularity. Timing.
Think of them like the legs of a chair. Lose one, and your health collapses.

In the podcast, Dr Vikki Petersen explains how to reset sleep, its connection to weight, fat loss, and how to avoid dying prematurely.

Quantity - Shorter sleep = a shorter life. Predicts all cause mortality.
Recommended is 7 to 9 hours. 7 is minimum to survive - not what you need to thrive.

Quality - Important for mental health. AKA sleep efficiency-want to keep it above 85%. Desired  is 1 to 2 long bouts of sleep vs fragmented sleep due to awakenings. 

Regularity - decreases risk of all-cause mortality by 49%, risk of cancer by 39%, risk of heart disease by 57%. 
Regularity refers to wake & sleep time.
Best to keep it within 15 minutes on either side
Worst was a variation of 90 to 120 minutes.
You need both, but regularity beat out quantity in reducing all cause mortality.

Timing (aligning with your natural body clock, or chronotype), using light cues (morning sun, dim evening light) to set it right. 
E.g. morning lark, night owl - but most people fall in the middle - bears.

Sleep Killers
Artificial light - Artificial light confuses the brain -“junk” light. Think candles - a little essential oils added
Eliminate
Alcohol
Caffeine
Marijuana
Eating before bed - wait 3 hours

TIP to help you fall asleep
For 7 days set alarm 1 hour before bedtime. Turn off most of the lights, candle light is fine, cool room to 68 degrees F. Do you feel more sleepy?
Go back to your regular routine & note difference.

Set an alarm to wake up 8 to 9 hours after your regular bedtime. As your sleep quality improves you won’t need an alarm.

Don’t skimp on that last hour of sleep - impacts mood, learning and mental performance - very restorative

TIP to help you get back to sleep - described in video
3 options:
Box breathing 
Body scan
Mental walk 

Weight and Sleep
How you sleep dictates what you eat and how you burn calories
Underslept = Cravings
Leptin and ghrelin go in opposite directions when underslept-increases your hunger drive 40%.

Burning calories
More likely to store calories as fat when underslept vs storing them as glycogen in muscles.
Dieters: lost the same weight but poor sleepers lost 70% of weight from lean muscle while keeping the fat. 

Fasting
Longer fasts your body makes more Orexin - hormone promotes wakefulness & appetite. May see your sleep scores drop during longer fasts

Melatonin - do you need it? Helpful to prevent jet lag or if you’re someone who doesn’t get sleepy until 3 to 4 am.
It doesn’t make you sleep or generate sleep - it starts the sleep cycle. 

Doesn’t improve the speed you fall asleep or the efficiency in any meaningful way. 

Safe dose is 0.1 to 3 mg. More not better because you can confuse your morning brain - melatonin should be zero in the morning - taking too much will cause you to have levels of it for the first 3 to 4 hours and you’ll be groggy and needing caffeine.

Note: it’s otherwise safe and an anti-oxidant, but there’s been erroneous data re; amounts that are too high. Don’t give it to children - melatonin is a hormone that influences puberty and some studies indicate that it can perhaps stunt reproductive development. Short-term use seems safe, but long term is concerning.

Magnesium - most doesn’t cross blood brain barrier, except L-threonate. But just being insufficient makes a difference - 50% of us are. Magnesium relaxes muscles and vagus nerve is activated with relaxation.

References:
1.Windred D, et al. (2024) Sleep regularity is a stronger predictor of mortality risk than sleep duration. Sleep 
2.Cribb L, et al. (2023) Sleep regularity and mortality... eLife
3.Miao Y, et