When it comes to fat loss, sleep is often one of the things people turn to last. However, in my opinion, ensuring you are achieving optimal sleep should be one of the first things you do to ensure you achieve the very best results possible and feel at your best day-to-day.
Let's look at two studies that do a great job of emphasising the role of sleep in fat loss.
The first study took a group of participants and split them into two groups:
One group slept for 5 hours per night for 2 weeks.
One group slept for 7.5 hours per night for 2 weeks.
Both groups were fed an identical diet to ensure they were in a calorie deficit.
Both groups lost a similar amount of weight (approximately 3kg), but the differences in fat loss were stark: -
The short sleep group lost only 0.6kg in body fat as compared to the longer sleep group who lost an average of 1.4kg.
So as you can see, sleeping fewer hours can have a huge impact on your ability to lose fat.
"These results highlight the importance of human sleep for the maintenance of fat-free body mass during periods of reduced energy intake"(Nedeltcheva et al, 2010)
The second study by Brondel et al (2010) took a group of 12 who were put into 2 different conditions for 48 hours:
8 Hours sleep
4 Hours Sleep
After each condition food intake and activity levels were assessed.
In comparison with the 8 hour sleep session, subjects consumed 22% more energy on the day after sleep restriction.
"These experimental results suggest that sleep restriction could be one of the environmental factors that contribute to the obesity epidemic."(Brondel et al, 2010)
The take home point here is that sleep is absolutely critical to fat loss. Lack of sleep or disrupted sleep has been found to increase losses in lean body mass. This is why I created a whole section on sleep and it’s importance in my FAST 28 Fat Loss Plan.
So before you get too bogged down with small details around your training and nutrition, make sure you are consistently getting good sleep to ensure you maximise your results.