How Sleep Deprivation Affects Fat Loss and Performance

How Sleep Deprivation Affects Fat Loss and Performance


I wanted to pop over a quick message to you on sleep…..

It came into my head after a big week in Tenerife (video here) if you want to watch what we did) last week on a training camp and getting back from the airport at 2am and then spent most of yesterday eating my lunch early, and hunting for food.

I was reading a study by Karine Spiegal and colleagues, who looked at sleep and hunger. They found that just two nights of restricted sleep were found to significantly impact hormones related to appetite and drive to eat,
as well as self-reported hunger.

In their study, they took people who usually slept 7-9 hours per night and had them sleep at consistent times for normal duration in the week leading to the study.

In one condition, they had sleep restricted to 4 hours in bed per night, for 2 nights.

In the other, they had extended sleep of 10 hours in bed.

When comparing the restricted sleep (4 hours) to extended (10 hours), participants had:

✔18% lower leptin levels
✔28% higher ghrelin levels
24% higher hunger levels

When leptin is lower it tends to act as a signal of reduced energy availability, leading to homeostatic drives to eat food and move around less.

Ghrelin can be thought of as “the appetite hormone”.

Given that this was looking at just 2 days of sleep restriction, it’s not difficult to make the leap to concluding why on going sub-optimal sleep works against us eating an appropriate amount of calories. It primes us to consume more calories and expend less. 

Even if having the best intentions with your food intake, sleep restriction means you’ve started the day facing an uphill battle.

Not only is sleep crucial for its direct benefits, but also for the indirect results it offers.

Hope this helps to remind you of how important sleep is….it certainly did me!

If you need help with your health and fitness goals,  don’t be afraid to reach out (

Speak soon,

Matt 🙂 


Owner of MattLuxtonHealthandFitness

Voted Cornwall’s Best Fitness Instructor 2016

Voted The UK’s Most Innovative Fitness Entrepreneur 2012

International Best Selling Author of The Fad Free Fitness Formula

Author of The Hot to Trot Cook Book and The Equestrian Athlete Plan

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