Intermittent Fasting - My Discoveries and Experience So Far
Several years ago I was asked to write a piece for the Telegraph on the subject of the 5:2 diet and intermittent fasting in general. Back then I will admit that I was not exactly an avid fan back then. Roll on 4-5 years and things have changed somewhat and intermittent fasting is something I am actually experimenting with personally to great effect. I began researching it more deeply and a genuine fascination has been roused. Its early days but here is what has been reported as well as my own findings practicing this.
Gives an added edge to weight management
So this first benefit should be quite obvious. Intermittent fasting does accelerate weight loss (within reason obviously). Now, this has nothing to do with calories, and anybody doing my ‘Diet Another Day’ programme will know how I feel about the calorie model of weight management. Intermittent fasting works on a different, and very simplistic mechanisms. What we need to remember is that our bodies are designed to respond adequately to feast and famine. During the biggest chunk of our evolution Humans had times when food was abundant, and times when food was scarce. We have responses to both of these situations hardwired into our DNA.
When we eat, our blood sugar rises and the body produces the hormone insulin. The amount of this produced will be influenced by the macronutrient (protein, fat, carbohydrate) composition of the meal in question. When blood sugar rises and insulin production goes up we are in what is termed the fed state. We can use some of this available energy straight away, and we can store some in the form of glycogen. This however uses only a smallish amount of the available energy. We can only burn so much, we can only store so much glycogen. Any left over will be shuttled to the liver and converted into a type of fat called triacylglecerol by means of a reaction called lipogenesis. This creates a form of stored energy that can be shuttled away in unlimited amounts for when food supplies are low and can then be released as a fuel source. How often does that happen to most of us?! When food intake goes down, insulin goes down, glycogen is used (although remember we have a small supply of that), then once glycogen stores have been used, we shift over to tapping in to fat stores as an energy source.
Intermittent fasting allows this process to kick in. An extended window of time without food will make insulin drop and switch us over to burning fat stores. This can get pretty complicated and is a key area of discussion in the education platform in Diet Another Day.
May help to prolong life
Something that has come from research, including studies published by Harvard have shown that caloric restriction or periods of energy restriction such as intermittent fasting can influence cellular ageing. One of the hallmarks of cellular ageing is a disorganisation of the mitochondria, which are the energy factories in our cells. Their performance begins to decline as our cells age and our capacity to make energy and rejuvenate begins to decline. Intermittent fasting has been shown to prevent and even reverse disorganisation and dysfunction of mitochondria.
The second way that intermittent fasting slows ageing, at least at a cellular level, is by increasing the expression of genes called sirtuins. These are genes that protect our cells from damage, particularly from oxidative stress - one of the key factors in ageing and disease. Intermittent fasting causes a gentle increase in oxidative stress and free radical production. Our cells respond to this by increasing their expression of sirtuin genes. The more on hand, the more able we are to cope with ongoing free radical stress.
May give an athletic edge
One of the benefits from intermittent fasting that may seem counter intuitive is that it seems to enhance the outcomes of athletic endeavours, particularly muscle gain. This isn't the first thing that you would associate with restricting calories I know, but like the weight loss benefits, it is the impact upon hormones that makes the difference. Intermittent fasting can increase the production of Human Growth Hormone. This hormone, along with Insulin-like Growth Factor helps us to recover from load bearing exercise and enhances muscular recovery and growth.
My own experience
So, thats what the research points to in terms of benefits. I have been implementing this for a few weeks now and have already seen some interesting results.
Im getting leaner. Fact. At 41 staying lean can be more challenging than it was 10 years ago so I have had to change my approach to exercise and diet. Exercise wise I have been doing CrockFit, and then with diet I have been doing low carb, moderate fat and protein, lots of non starchy plant foods and now intermittent fasting - skipping breakfast and having my first meal at 12 noon, and my last by 7pm at the latest. I’ve been getting leaner faster and have noticed a marked difference in body composition already. This coupled with a response to exercise that is much rapid than ever before. Ive been exercising since I was 15 so its nothing new to me, but this diet seems to have helped me get much better results faster. The growth of muscle has actually been quite staggering in a short time. I have been training first thing in the morning with nothing but a strong coffee for fuel.
The other thing I have noticed is the mental clarity and creativity that has gone into overdrive. Ive always had an active brain that I struggle to shut up, but it has stepped up a notch and with this has come enhanced creativity. There is some trace of evidence that the brain and nervous system responds favourably to intermittent fasting, although the mechanisms behind this aren't totally clear. It could be something to do with ketone body production. Ketones can act as a very effective fuel source for the brain.
The other thing that I have noticed is a consistency in energy levels. The first couple of days Im not going to lie, I was tired and irritable and absolute STARVING until lunch. But, after day 3, this went and a mental clarity and calm set in instead.
Its early days with this but I think there could be something to it, and I will keep you guys updated on social media as to how this pans out.