Thousands of fitness professionals and bloggers claiming that fasting is making them feel healthier, more alert and gives them a clearer mind but is there any medical research that actually backs this? Fasting diets are never the same. You can fast for a set amount of hours a day, for full days, alternating days, with water, without water… it depends on the reason and how much determination you’ve got!
The 5:2 diet is one of the more popular types of fasting with the idea being that for 2 days a week, you will limit your calorie intake (some choose to fast completely) and for the other 5 days you will eat like you usually would. Those 2 days can be any 2 you choose and it doesn’t have to be the same each week. The bonus of this is that you can pick your days, based on what your days are looking like. If you know you’re having a lazy Sunday at home where you won’t use much energy, you may choose to do it then. Or you may choose to do it on a busier day where you’ll be so busy that you won’t have enough time to even think about being hungry!
So why do people fast?
Some people decide to fast in order to cleanse their body. When you begin your fast, you immediately stop adding toxins to your body and your body stops using the energy it normally takes to digest your food and starts using that energy in more beneficial ways. The term ‘starve a fever’ comes into play here- with the extra energy your body now has, it can start fixing other parts of you which may be suffering; whether that’s toothache, a twisted ankle or another illness!
When you eat, your body breaks down carbohydrates into glucose which is your body’s main source of energy. The glucose gets absorbed into the blood and travels to your cells to provide them with fuel. When you begin to fast, various things begin to happen in your body:
- Your glucose supply begins to drop and your body turned to its stored glucose to provide it with energy
- Once the stored glucose is used up, your body begins to burn fat to make its own glucose.
- After a few days of complete fasting, your body kicks into ketosis mode where it will burn fat as its primary source of fuel in order to stop it using muscle stores.
In this mode, you will lose weight but it does come at a price. In ketosis mode, your blood will become more acidic and can cause bad breath, fatigue and other unpleasant symptoms. The longer your fast lasts, the more likely it is you kidney and liver will become damaged and start to fail.
If you’re fasting to lose weight, you may want to think about the process after the fast finishes. If you’re not careful, you can pile the weight back on just as quickly as you lost it. When your body is starved of food, it’ll go into ‘starvation mode’ and your metabolism can slow down; this can sometimes result in regaining your weight when you go back to your usual diet.
Regardless of the reasons behind why people fast, the one big debate surrounding fasting is the surrounding how safe it is. Some claim it’s safe for 1-2 days, some claim you can go for days and days without eating, but realistically for the normal adult, is days without food really that wise? One of our brave activeNewham staff members, Joe put fasting to the test…
Plan: 5 day water fast – 5 days of drinking water, but not eating anything.
After stumbling across a video online by Nephrologist Dr Jason Fung about Therapeutic Fasting, I decided to try it myself and dive head first into a 5 day water fast. The first day wasn’t too bad, I kept myself full by drinking lots of water, and I managed to survive a CrossFit session too! The hardest part of the day was actually trying to get to sleep, but I got there eventually. Day 2 was hard. Again, I drank lots of water and attended another CrossFit session, however after that I felt like I just needed to eat, so I held on for the 48 hour mark and then had a mini feast, I kept it clean though by eating a Vegan Falafel Salad…. Or 3..! This was the point where I decided that if it wasn’t for CrossFit, I might have been able to carry on the fast so I decided to mix things up and went from a full blown water fast, to intermittent fasting. I gave myself an 8 hour eating window and was fasting for the remaining 16 hours of the day, which I actually really enjoy! The 5 days was up and I’ve continued with the fast – what was meant to be a 5 day fast has turned into a 48 hour fast with prolonged intermittent fasting!
Pros: Improved sense of smell. Increased focus/alertness. Weight loss. Saves money. Increase water consumption.
Cons: constantly thinking about food.
Joe is a young, healthy guy who is always careful with his diet and is a keen CrossFit member and even he found the original plan wasn’t for him. Realistically, anyone should consult their doctor or health professional before undertaking a drastic diet change but under no circumstance should you fast if you fall into any of the following categories:
- If you’re pregnant or breastfeeding
- If you suffer from a chronic disease
- If you have any heart, liver or kidney problems
- If you’re diabetic
- Children
- The elderly
Fasting is nothing new with people giving up food for religious reasons and our ancestors were never gorging on big meals made up of food bought from the super markets! However it’s a big change for your body and can take its toll. So before you decide that fasting is the way forward, do your research, make a plan and prepare appropriately.
If you've experimented with fasting before and got any handy tips for helping others when they may be struggling, let us know in the comments below!
