Sleep to Lose Weight!

postpartum-exhaustionThink back to a time when you felt so tired that it felt as though someone attached weights to the ends of your eyelids; when you realised that the expression bone-dead tired literally meant your bones ached. Did you feel like whipping up a healthy salad? Did you feel like going to the gym to pump out a weights session or do CrossFit? Lacking motivation in times of exhaustion is not uncommon, nor unexpected. This is one reason why sleep or lack thereof may contribute to weight gain; however there are other more physiological reasons as to why sleep deprivation impacts on your weight.
According to the Australian Sleep Health Foundation, adults need approximately 7-9 hours of sleep per night. Teenagers and school aged children require slightly more ranging from 8-11 hours. Poor sleep affects our appetite hormones, increases our blood glucose levels, and can even increase hormones known to store weight such as insulin and cortisol.
What does poor sleep mean though? Our bodies run on what’s known as a circadian rhythm (our body clock). The time of day/night that we go to sleep appears critical. It is proposed that shift workers are more susceptible to weight gain as result of altered sleep habits and disruption to our circadian rhythm. Additionally, sleep quality and duration are crucial in determining the quality of our sleep. While sleeping we transition through a number of stages. They are broadly categorised into either rapid eye movement (REM) or non-rapid eye movement (NREM) sleep. The initial stages of sleep are the NREM sleep. These are NREM1, NREM2 and NREM3 (or slow wave sleep). It is in NREM3 or slow wave scircadian-rhythmleep where restoration occurs. This is the deepest stage of sleep and it’s where our heart rate, breathing, and blood pressure decrease. Our muscles are most relaxed during this stage. Certain diet behaviours can impact the time we spend in slow wave sleep. A recent study found that a diet low in fibre and high in both saturated fat and sugar decreased the amount of time we spend in slow wave sleep. Furthermore, caffeine and nicotine have been found to decrease slow wave sleep duration.

So let’s look at a few of the side effects of poor sleep mentioned above…
Cortisol, it’s our primary stress hormone that increases our blood glucose levels, contributes to the breakdown of muscle tissue, and deposits adipose tissue (fat) around the abdomen. Poor sleep quality rather than quantity has been linked to increased cortisol levels. images (1)A number of factors may impact on sleep quality, however common influences are excessive caffeine intake (caffeine has been found to remain in the system for up to 14 hours), poor sleep habits (reading phones and devices in bed), urinary habits and stress. As you can see, looking at strategies to reduce these factors is essential for reducing excess cortisol production.
What about the appetite hormones. Ghrelin is a hormone that increases hunger, while leptin is a hormone that suppresses appetite. These two hormones are affected when both sleep duration and quality are affected. One study found that poor sleep increased ghrelin (tdownload (1)herefore hunger), decreased leptin (in other words more hunger again), and lastly increased BMI (not surprising given the increase in hunger). I tend to think of our body in terms of evolution, if we are awake for longer than it would make sense our bodies make us hungrier to feed these extra waking hours.

Sleep has also been linked to risk factors for heart disease. A review of the evidence found poor sleep behaviour contributed to metabolic syndrome which is a cluster of risk factors such as hypertension (high blood pressure), obesity and elevated blood glucose levels.
So what can we do to improve our sleep and maintain a healthy weight? Click here to see 10 tips to achieve a good night sleep from the Australian Sleep Health Foundation. A good bed routine and sleep hygiene seems to be a great start. Evaluating your caffeine intake is also important, while being aware of the timing of your fluid intake may also prevent you from waking all night with the urge to go to the loo. Maintaining a healthy diet and maintaining a consistent exercise routine, are not only crucial for achieving a healthy weight, they are also great in order to get a good night sleep. We now live in a world with a 24 hours news cycle and subsequently our sleep duration has decreased over the last 20 years. For something that we should be spending approximately 30% of our lifetime doing, sleep is an often underestimated daily ritual; therefore prioritising your sleep is a good place to start.

Lose fat, gain muscle.

Lose Fat, Gain Muscle!


The vast majority of young athletes I work with are often striving for muscle gains or fat loss and often both at the same time. This is not an easy task given that one requires an anabolic (growth) process, and the other a catabolic (declining) process. Fat

The first law of thermodynamics states that energy can neither be created nor destroyed. In other words, for weight gain to occur there must be excess energy left over in our diet after sufficient energy is provided to fuel our metabolism, thermogenic effect of food (digestion) and physical activity. Similarly, energy cannot just be destroyed, therefore it must be burned by the body (and not replaced through our diet) if it is to be seen as weight loss. This is an oversimplified summary of an otherwise extremely complicated physiological process. Numerous other elements that are beyond the scope of this blog are involved in the process of weight management, however this concept is still at the foundation for all weight management.

Both muscle and fat can be converted by the body into energy. The body will only do this if the supply of energy provided through the diet is inadequate. This is known as an energy deficit and is the goal for many a weight loss intervention. If the body is in an energy deficit then it looks to use up any available resources. Those resources can be in the form of glycogen (which is the body’s storage form of carbohydrate), adipose tissue (fat), or muscle (protein). When this process occurs fat is known to yield the most amount of energy with approximately 37kJ (9Cal) for every gram of fat burned. Alternatively, protein (which is the major component of muscle) yields only 17kJ (4Cal) per gram. This works the same when fat and protein is consumed in the diet. You are required to work harder and burn more kilojoules if there is a higher consumption of fat in your diet, due to the higher kilojoule content for every gram of fat. Fat V Muscle

So the often asked question regarding the ability to simultaneously lose fat and gain muscle has recently been researched at McMaster University in Canada. This study was able to look at two groups of young males each provided with a diet that consisted of a 40% reduction in kilojoule intake based on their ideal kilojoule requirement to maintain weight. Each group was provided with 50% of their kilojoule intake from carbohydrates (therefore any outcome was not related to changes in carbohydrate intake). The main difference in the diet provided to the participants was the composition of fat and protein. The low-protein group consumed their kilojoules via approximately 15% protein (1.2g of protein/kg of body weight) and 35% fat, whilst the high protein group consumed approximately 35% of their kilojoules from protein (2.4g protein/kg of body weight) and 15% from fat. All the participants performed resistance exercise training in conjunction with high intensity interval training for six days per week. Body composition was assessed both pre-and post-intervention.

This study has gone a long way to answering the frequently asked question regarding the possibility of losing fat and gaining muscle simultaneously. The results showed that both groups managed to lose weight and specifically fat loss. The lower protein group (at 1.2g of protein/kg of body weight) did not show any muscle wastage despite being in energy deficit, however did not show any muscle gains. The high-protein group (at 2.4g of protein/kg of body weight) was able to show gains in lean muscle tissue while simultaneously shedding body fat.

Training The amount of training performed throughout this trial, in addition to the higher than recommended protein intake (usually 0.8g-1.0g of protein/kg of body weight) even for the lower protein group, might explain some of the reasons as to why no muscle wastage was observed despite such a significant kilojoule deficit of 40%. The 40% kilojoule deficit clearly resulted in the catabolic process of fat breakdown. Most likely there was significant muscle breakdown as well, however the higher intakes of protein replaced this muscle breakdown therefore resulting muscle tissue gains.

The results of this study are encouraging for anyone looking to improve performance and/or appearance. Translating this evidence into practice requires an appropriate training programme and an analysis of your current energy and protein intake. An accredited practising dietitian (APD) can assist you in determining your current protein intake. Importantly an APD can also provide you with diet strategies to achieve the required 2.4g of protein per kilogram of body weight, as indicated in the high-protein group in the study. No doubt for some this research will only be reinforcing their belief regarding the ability to gain muscle and shed fat simultaneously. This research does however shed light on the previously shady area regarding the specific dietary and training requirements to achieve this outcome.