I've just watched this programme in UK TV and for those of us outside UK I thought I'd outline his advice on getting a good nights sleep.
Eat high fibre foods during day time i.e. Lentils/chickpeas:butter beans etc:bananas/onions - they feed good bacteria in our gut
Take a prebiotic 1 hour before going to bed / it feeds the good bacteria in our gut!
No electronic devices on bedroom. Cease using any social media 1 hr before going to bed
Go to bed around 9.00 pm but get up early and go outside to get benefit of morning light.
Bedroom 17 degrees
Hope that helps.