A 7-day Intermittent Fasting experiment

I’ve been interested in Fasting ever since I saw the Michael Moseley Horizon programme in 2012, not just for weight loss reasons, but rather the claimed health benefits – lowering the risk of developing diabetes, dementia and cancer.

Fasting purportedly diverts energy and resources away from food digestion, focussing instead on doing useful housekeeping things like cell repair, reducing insulin levels and generally ridding the body of toxins and other debris. It also re-teaches the body the lost art of deriving energy from fat, as opposed to from the carbs in our belly – a process called Ketosis. Most of us carry enough fat to survive several weeks without food, which is why fasting is safe, and why many people have successfully conducted 21 or 28 day fasts without any harm.  It’s also popular in many religions and spiritual practices – Islam (Ramadan), Buddhism, Bahá’í, Christianity, Hinduism, Judaism, Jainism, Sikhism, Taoism … the list goes on.

Even outside of religion and spirituality, fasting has been a natural part of human existence for as long as we have been around, primarily because food was scarce and so early man had to eat when he/she could, forced to fast in between hunts and catches. We are therefore designed to cope well with fasting, it’s in our genetic make-up, even if it does feel a little alien to the modern psyche which has been raised on the 3 square meals a day regime (3SMAD). The introduction of 3SMAD has its roots traced back to 19th Century America – it was a symbol of civilisation to sit down with friends and family at fixed times to eat, an attempt to differentiate the ‘civilised’ white man from the indigenous natives. It could therefore be argued that fasting is more natural to us than 3SMAD.

Nevertheless, many people will still argue that 3SMAD is best for us and that fasting is sheer madness. People will claim they feel ‘shaky’ if they miss lunch, and cite this as evidence they need to eat, but there is a counter-argument that your body has just become so dependent on deriving instant energy from food carbs that it’s forgotten the lost art of ketosis which fasting allows.

I therefore decided to give it a go for a week. Instead of the traditional 5:2 diet which I followed for a year or so but found rather difficult, I decided to try just eating one meal a day, every day, limiting my calorie intake to a couple of hours each evening. That means eating nothing whatsoever for 22 hours – no sugar or milk in tea, certainly no snacks or fruit, just water, tea and an occasional black coffee. You could call this the 7:0 diet – a little extreme maybe, but if the theory of ketosis is sound, I figured it wouldn’t be anything more than a psychological challenge. If you want more detail on this, I got the idea from the following video Eating Once a Day.

Important to note I placed no restrictions on what I ate (or drank) in these two hours. I didn’t cap calories or consciously cut out any food groups.  I even allowed alcohol because I know if I had banned it, I would have fallen at the first hurdle. What is interesting, is what happened:

My Diary

Day 1 – not surprisingly this was easy, after all I had a corpulent body full of yesterday’s 3SMAD excess calories to keep me going. I didn’t want any alcohol and just ate a moderate plate of veggie grub.

Day 2- felt good, loved waking up and not having to worry about food all day, a feeling that persisted throughout the week. Interestingly I only had (only wanted, only needed) a light meal, although it was accompanied by a glass of wine. Day 2 was a Friday, and had I banned alcohol in this experiment, I may have felt resentful and rebellious. However, without any alcohol ban I was free to enjoy a glass, and because I felt good about the fasting, I wasn’t tempted to drink any more, ending the evening feeling unusually virtuous and sated.

Day 3 – felt good, went for a long walk during the day (4 miles), had a veg stir-fry for dinner plus two glasses of wine (it was Saturday night). I didn’t really enjoy the second glass of wine – one would have been enough but in a perverse mindfcuked reasoning kind of way that only I could muster, I convinced myself I should have a second glass to prove to myself I wasn’t restricting alcohol.

Day 4 – hard, very hard. Perhaps it was the wine? Who knows, but I had a persistent headache all day, felt tired and sluggish despite sleeping well and craved food throughout, occasionally staring balefully at the cheddar cheese in the fridge. I only just made it through to tea-time, but interestingly didn’t have (or want) any alcohol. Veg Thai green curry (no noodles).

Day 5 – much better. I was busy which helps a lot and I just had a light veg dinner. No alcohol. I definitely felt lighter and I’m definitely sleeping better and eating much healthier food through choice/desire. No cravings whatsoever for junk food (odd for me) and most surprisingly of all, despite not restricting alcohol, I’ve only had 3 glasses of wine in the first 5 days, including a weekend, and anyone that knows me will know that’s quite uncharacteristic.

Day 6 – all went well, seems to get easier. Had a light veg based dinner, no alcohol. Sleep continues to improve. Once again my focus and concentration was immense, far better than usual and my work productivity has undoubtedly increased. Managed a 2.5 mile run.

Day 7 – felt harder. Perhaps knowing this was the last day made me psychologically weak, like I sensed the finish line. But that makes it sounds like it’s been a hard slog and it really hasn’t. I’m only stopping today because I set myself a 7-day target for this experiment and the more I look at it, the more I believe I could continue further. I survived and rounded off the 7-day fast with an oven baked jacket potato and cheese like mama used to make. Enjoyed a 3-mile walk.

In summary

I would say on average I have consumed well under 1,000 calories a day, probably closer to 600-700, and interestingly have eaten smaller portions and higher quality evening meals than I ever did on 3SMAD. I also rarely craved junk food and 3 glasses of wine was well under par for me for a weekly total. I also ate total vegetarian – due in part to a bountiful supply of garden produce, but certainly not a conscious action at the outset of the experiment, perhaps this was pure coincidence.

Of course 600-700 calories a day isn’t sustainable long term, but I guess that’s where ketosis comes in, at least in the short term. I have AMPLE fat stores to draw upon, as do most of us fortunate enough to live in the western world, and so such a challenge over a relatively short period of time is only ever a psychological one I think. This was never going to be, nor ever planned to be, sustainable, I just wanted to check if it was doable, and it was. It’s foolish to draw any firm conclusions, but it has proved to me you don’t have to eat at set meal-times, it’s OK to skip a meal (or two), and in fact it might even be good for you to listen to your body rather than the chimes of the clock.

I have no idea what it has done for (or to) my health, all I can say is I felt better afterwards than I did at the beginning. I felt like I had more energy and my brain was definitely sharper – I could concentrate for longer and didn’t feel sleepy during the day. For the record I lost 3.4kg (7.5lbs) in weight. No doubt much of that will go back on when I return to normal eating, although, and here’s the crux, I’m not entirely sure I will return to my normal 3SMAD eating, but perhaps somewhere in between.

I’m certain many of you will think this was a silly and dangerous thing to have done. All I can say is I survived and as described above I felt better than I did previously. Best of all I believe I now have a much better perspective and handle on my, admittedly rather quirky relationship with food (and maybe also drink).