Nutritionist Sarah Di Lorenzo: Why is sleep so important for weight loss

I always see the approach to losing weight as holistic.

There are so many factors that need to be addressed such as diet, stress, exercise, hydration, relationship with food, alcohol consumption, any underlying diseases or nutritional deficiencies but did you know that the amount of sleep can impact your weight and your weight loss journey?

The length of time you sleep can determine how much of your weight loss is fat and how much is muscle.

Those sleeping seven to nine hours per night generally lose fat and those who sleep four to six hours per night will tend to lose more muscle.

We all know the weight journey is hard enough but this with a combination of lack of sleep just makes it that much harder.

Interestingly, did you know that 66 per cent of Australian adults have some kind of sleep problem.

Research shows people who sleep less than six to seven hours per night have been shown to have a higher body mass index, weight gain and a greater waist circumference.

This indicates an increase in visceral fat, the fat dangerous to our health leading to obesity and associated diseases.

Lack of sleep impacts our hunger levels.

When we are tired we are more inclined to consume foods high in sugar and high in fat.

Fatigue will increase the production of the hunger hormone ghrelin and decrease leptin, the hormone that tells us when we are full.

Put simply, sleep is essential to control your appetite and prevent increases in calorie intake with poor food choices.

There was a great study demonstrating those who were sleep deprived consumed an additional 385 calories per day and it was not for protein rather chocolate, portions and fat.

This is all related back to hunger hormones ghrelin and leptin.

Less sleep means the body makes more ghrelin and less leptin, in simple terms you are hungrier and it takes a lot longer to feel full — no one wants this.

When we sleep well we make better food choices, lack of sleep alters decision making and the way our brain functions, simply making it so much harder for us to make a healthy choice when sleep deprived.

Plus the reward centre in the centre of our brain appears to be more stimulated when sleep deprived.

Think about being exhausted and eating a block of chocolate, it is so much better tasting than when you are sleeping well.

When it comes to late night snacking, going to bed earlier bypasses that.

Many of us who go to bed late end up prowling around the kitchen around 10pm looking for a sugary snack, in fact did you know that when sumo wrestlers are trying to gain weight they do all their eating late at night as it is when the body will store fat most efficiently.

When it comes to sleep and our metabolism, our resting metabolic rate is a measure of the calories we burn when we are at rest and is impacted by gender, muscle, age, weight, height and the amount of sleep we get.

Sleep deprivation reduces our basal metabolic rate as seen in some research.

So how much sleep do we really need so we can get to our healthy weight and stay there?

The recommendations for an adult are between seven to nine hours per night.

My tips are to make sure you are doing regular exercise, this has a positive impact on your appetite and helps reduce ghrelin levels especially after exercise, plus exercise can protect against the metabolic impairments from lack of sleep by improving the body’s response to inulin therefore improving blood glucose.

As well I tell my patients to look at sleep like a job, aim to go to bed around 9pm or 10pm, no phones in the room, rather meditate or read.

Make sure you are sleeping with the window open even in winter, avoid eating three hours before going to bed, avoid alcohol, no caffeine after 12pm, be sure the bedding is fresh and you have a good pillow.

My other tips are to consider taking some magnesium and always shower or have a bath just before bed.

For those waking through the night it is important to try to understand why and consider seeing your doctor for a full check up.

Once you focus on good quality sleep you really will see the difference after all sleep is king and where all the magic happens.