Carbs at Night Time 🍯
Growth hormone is an essential hormone produced in the body by the pituitary gland, it stimulates growth, cell repair, and cell regeneration. It has a primary role in maintaining body fat levels, metabolism, and lean body mass; so its best to ensure growth hormone levels are managed well!
Sleep is the greatest inducer of growth hormone, and our hormone cycles whilst in the sac occur primarily, if not exclusively, during the slow wave sleep phase in the first 3 hours of sleep. This graphic shows the stages of sleep with level 4 being the deepest:
(image courtesy of: http://thebrain.mcgill.ca/flash/i/i_11/i_11_p/i_11_p_hor/i_11_p_hor_1c.jpg)
Slow wave sleep is also the primary arena for melatonin production, one of the bodies most powerful anti-oxidants. Notice growth hormone and melatonin peak around the same times whilst cortisol is low. As cortisol elevates towards waking, growth hormone has completely diminished, and melatonin is quickly lowering.
Its important to prioritise our sleep cycle and preparations for sleep to utilise the maximum benefit from growth hormone and melatonin. Cortisol is important, it wakes us up and slowly lowers through the day in peaks and troughs. Whilst energising and important for many bodily processes, it is important this hormone is not present before bed as it will disrupt our sleep. Things which elevate our cortisol are: STRESS!! anything from work pressures to arguments and anxiety, caffeine, intense or prolonged exercise, fasted states, infections.
Methods to reduce cortisol levels are obviously stress management techniques like meditation/yoga/tai chi, cutting caffeine out after 1/2pm, exercising in the first portion of the day. It's also consuming complex carbohydrates in the evening such as boiled grains, plenty of vegetables, some starchy veg like potatoes, not really refined or processed carbs, definitely not sugar.
Carbs trigger the release of insulin and when insulin is present it reduces the levels of amino acids in the blood allowing tryptophan - the precursor to serotonin - to cross the blood brain barrier and increase levels of serotonin. Serotonin is the hormone responsible for relaxation and elevated mood, the perfect storm for restful sleep, and the arch enemy of cortisol.
Carbs at night time defies the general consensus that a large meal before bed is bad, and especially a carb heavy one. There is a cool video at the bottom of the page, where Nate Miyaki explains the hormonal impact of carbs at night and the correct timing to ensure good growth hormone release during sleep.
The take homes are:
- Growth hormone levels have the first high peak during 60-90 minutes of sleep.
- Insulin levels last for around 2-3 hours and when they return to baseline levels, growth hormone is stimulated. So ingest a carb heavy meal in the evening at dinner time, 6/7pm, so by 10/11 your insulin levels will have returned to baseline and GH will be stimulated in the first window of sleep.
This also mean you get the cortisol suppressing and mood elevating effects of insulin, and the growth hormone promoting effect of low insulin by the time you are asleep.
Hunger before sleep is detrimental always because it elevates cortisol which disrupts sleep, and it causes the body to crave energy and often in the quickest form glucose (sugar), so chances are a midnight snack will be consumed and this will ruin the bodies growth hormone cycle.
