1. Eating at night
Eating at night alters the balance of hunger hormones leptin and ghrelin, which affect melatonin, insulin and thyroid function. Eating a large amount of calories at night goes against your circadian rhythm and can cause you to become insensitive to the hormone leptin if done regularly.
To improve this, identify a meal frequency that works for you and allows you to avoid eating the bulk of your calories at night. Eating breakfast in the morning has been shown to improve circadian rhythms. A normal rhythm causes an increase in the hunger hormone ghrelin in the morning.
A common scenario in people in high-stress jobs is they don’t manage to eat adequately during the day and cortisol is elevated for the duration, leading to intense cravings for pleasure, comfort foods (sugar). This often leads to evening snacking and overindulgence, altering leptin, ghrelin, and melatonin and sending them down the cruel road of altered circadian rhythms and hormone imbalance.
2. Fasting or Calorie Restriction
Both of these have been found to alter circadian rhythms and impede sleep because they activate neutrons in the brain that keep you alert and awake.
Evolutionarily it makes sense that when our hunter-gatherer ancestors lacked food, they still needed mental clarity and brain function to drive activity in order for them to find food. However, it is unlikely they were is a regular fasting state, as many people these days who practice fasting are.
Plus, even though our ancestors may have lacked sleep, their main job was finding food, whereas our main job, is to perform at work, whilst looking after a family and household whilst also completing a list of other responsibilities.
3. Screen time
Exposure to computer, TV and mobile phone screens decrease melatonin production. Avoid TV watching, mobile flicking, iPad searching, laptop working in the hour or two leading up to bedtime. Dim the lights, switch off all standby modes so there is no red or blue lights, get black out curtains
4. Too much or too little exercise, or training at the wrong time.
Late afternoon or early evening are the best workout times from a performance and protein synthesis standpoint.
Too much exercise, such as daily high intensity, chronic, long and intense cardio, or regular two a days may lead to elevated inflammation and hormone imbalance.
5. Lack of Vitamin D3
British people are commonly low in the Vitamin D3. The part of the brain responsible for sleep has a large concentration of vitamin D3 receptors, and the entire sleep-wake cycle is disrupted of the receptors are deficient. Vitamin D3 also influences many other hormonal processes in the body that affect body rhythms, including reproduction, metabolism, digestion, and cardiovascular health, all of which influence fatigue and sleep regulation.
It would be a good idea to supplement Vitamin D3 in your diet. You can get a blood test to examine whether you are deficient in Vit D3.