Why Your Sleep Is Affected In A Calorie Deficit

One of the many things that happens when you eat less than your body needs is that your body has the ability to wake you up, out of, even a very deep sleep when it deems you need more food! 

Very inconvenient but your body is the master at telling you what it needs! 

Sleep disruption is a common issue in a calorie deficit and it's another reason why I go on and on and on about only being in a calorie deficit for a defined period of time, it's not a lifestyle! 

Peri Menopause

All of this is especially important to understand if you are in Peri Menopause/Menopause because sleep disruption (from fluctuating Progesterone and Estrogen levels) could be made worse if you are in a calorie deficit. More reason to speak to your Dr and get the right information and or medication to improve your symptoms.

Sleep Study

In a recent study there were 2 groups in the same calorie deficit, one who got 6 hours or less per night and the other group got 7+ hours of sleep, guess which group had the best fat loss results? The 7+ hours sleep per night.

Why Is Your Sleep Affected In A Calorie Deficit

Firstly, a calorie deficit is simply consuming less calories than your body needs to maintain it's current weight. It a component of fat loss.

It is also a stressor on the body. Your body notices this energy shortage and it does start making adjustments, some good, some not so good. 

So, why do we experience these awakenings during the night? Not everyone experiences this but it is quite common.

Hunger Hormones - When you are in a calorie deficit, your body lower the production of leptin, the hormone responsible for signalling fullness to your body and at the same time you experience an increase in ghrelin, the hormone that triggers hunger. This hormonal shift not only makes you feel hungrier during the day but can also cause you to wake up during the night, especially if your stomach is growling.

This sensation for some people is enough to pull them out of a deep sleep, even if they don't fully realise it!

Elevated Cortisol - Even in a healthy calorie deficit we do see a rise in cortisol levels, in response to this, your adrenal glands that is their function, they produce more cortisol. Elevated cortisol levels can keep your body on high alert making it harder to stay in a deep stage of sleep. Cortisol also follows a natural rhythm it usually peaks in the morning and is declining during the day.

In a calorie deficit this rhythm can become dysregulated leading to night time spikes that wake you up making you feel really alert too when you wake up and then restless. Then in the morning you don't feel as good, you can tell you haven't had enough of that deep sleep.

Does this help you understand why living in a calorie deficit is a bad thing?

If we are changing these natural flows and rhythms in out body in a calorie deficit, I hope you can see that it is really important to get into your calorie deficit and get out in a timely manner! You should not be living in this state, if you care about your long term health anyway.

Low Carbohydrates -  If your calorie deficit involves significantly reduced carbs, your bodies glycogen (where your carbohydrates are stored) becomes depleted and this can lead to drops in blood sugar levels overnight, which triggers an internal alarm causing you to wake up.

Carbs play a role in the production of serotonin (a neurotransmitter) that helps to regulate mood and sleep, lower serotonin levels means less melatonin (the hormone responsible for sleep/wake cycles) making it harder for you to stay asleep.

Sympathetic Nervous System - In a calorie deficit you bodies fight or flight system can become more active this heightened alertness is thought to be an evolutionary advantage to keep us focused during times of food scarcity but it's not helpful when you are trying to sleep.

These micro awakenings prevent you from entering into really deep sleep as well. 

What Can We Do About It?

Avoid crazy, aggressive diets. Dieting under your RMR (Resting Metabolic Rate) is going to be worse than a moderate calorie deficit. Slow and steady wins the race.

Could Try A Melatonin Supplement. You will need to buy this from the US because it cannot be bought over the counter in the UK.

Use Some of Your Carbs Later In The Day. This could be some complex carbs like oats, sweet potatoes either before bed or just have more in your evening meal than earlier in the day. This can help to boost serotonin production and stabilise blood sugar and that can often help. 

Prioritise Protein & Fibre. These will keep you feeling fuller for longer.

Eat Enough Dietary Fats. These are critical for hormone function, which is in turn critical for sleep function. 

Be Off Your Bed A Few Hours Before Bed.

Set A Regular Wake & Sleep Routine.  Have a really good sleep hygiene schedule before you go to bed. Keep your bedroom, cool and dark, be consistent with your sleep and wale times. Avoid caffeine in the afternoon. 

Some hunger in a calorie deficit is normal, but it's about managing it so that you are not absolutely starving! You need to objectively assess if your deficit is too aggressive and try some or all of the solutions about.

Here's to a good night sleep and the results you want x