Going 5 days without food may seem wrong to you, but I saw some payoff I didn’t expect. The idea to go big with this fasting challenge came from Yes Theory. I saw a YouTuber, Matt, go 5 days without food. There was struggle and pain, and all of the things that come to mind when you think of going without food for that long.
But, I couldn’t forget his face at the end of the challenge – watching him take that mouthful of watermelon to a sluggish sheepish face afterwards was priceless. I could do this, I thought. This would be fun! I believed the challenge would reveal some physical insights hidden by our habits of constant comfort. Some people use fasting to lose weight, to strive for other nutrition and health goals, or for the mental focus hunger is alleged to sharpen. Personally, fasting for 5 days was a mental and personal challenge and the results were truly rewarding.
How many times do you think your mind drifts to consider food in a day? How many habits, like your commute to work or uni, or even the ‘commute’ from bed to the lounge, involve routine foraging for snacks? I found myself opening the fridge mindlessly at home, and walking through my neighbourhood to the usual cafe or lunch spot, even when I knew that a measly cup of coffee would break my fast. However, my mind would still repeat and generate recipes. I would make plans around an illusionary breakfast that would never be eaten. My drafted messages to friends asked “do you want to meet for… coffee… lunch… beer” before I deleted them in defeat. I cannot stress the persistence of food-based thoughts when you are trying to go without. To realise this was quite liberating. How would you plan your life if food was not needed in the day? How would you change your goals and channel your effort into hobbies with all this free time? I did a lot of productive life admin in that 5 day window.
I had a strange thought during the middle of the fast. Could I take a pill that would change how I’m feeling? This was a scary thought that I pushed away quickly at the time, but it returns to me. Why did I feel this impulse? The noise of hunger was so discomforting that I didn’t care to think of food anymore; I was not hungry physically, but I sought to find some mental relief. This was unsettling at the very least. I sank deeper into the challenge with commitment to what I was feeling, rather than running this thought into reality. I took a paracetamol the night before this strange thought, so maybe the part of my mind that was crafting pointless recipes was searching for another avenue to cheat.
Usually weight can be lost within a day of fasting as more water is offloaded to balance the lack of sugar and sodium in your body. But this is temporary. The balance of electrolytes and water is important, because if you eat too quickly after fasting you put yourself at serious risk of ‘re-feeding syndrome’ which requires hospital treatment. I broke my fast with a light meal on the grass outside of the Auckland City Hospital Emergency Department, just to be safe. Fat takes a long time to break down, and this process is basically just as slow if you’re big or small, hungry or not. Any calorie deficit will trigger this process, not just fasting. Fasting just has added risk, and the downside of breaking down proteins too. Basically, fasting for weight loss is not great. This is a good time to note that you should talk with a GP before embarking on a fasting challenge.
Heightened mental acuity from hunger has some evidence behind it, in that fasting increases brain derived neurotrophic factor (BDNF) activity. This gene component plays a role in neuron growth and brain plasticity. BDNF is associated with better metabolic health and a loss of it in humans is associated with severe obesity. Although, some of this evidence around the benefit from upregulated BDNF is difficult to accept, as it is in an early stage, and in some studies participants were unclearly selected from earlier experimental trials.
There is something empirically valuable about understanding what your body can do when the limits are pushed. I came out of this challenge with curiosity and skepticism as my primary feeling. I challenge you to be curious about your food habits! Don’t just follow the capitalist advertising narrative that you must eat every 3-4 hours to be happy. Being hungry is normal. Being without hunger for your whole life, I would argue, is not normal. If food is a chore for you, or a source of anxiety, I encourage looking into some creative options. This doesn’t necessarily mean days of fasting, but perhaps some careful restraint that could give you a healthier relationship with food. Sugar comes to mind… but that’s a challenge for another day.