What is Intermittent Fasting?
Intermittent Fasting is simply taking time off from eating on a regular basis. We all fast overnight (thus the term BreakFast) so extending the 10-12 hours that we naturally fast to a minimum of 16 hours can result in many health benefits. Fasting is not just a good way to lose weight; it also has a lot of other health benefits (some better researched than others).
How does fasting work?
As the body is unable to get its energy directly from food during fasting, it uses the glycogen (stored glucose) in the liver and muscles. This usually starts around 8-10 hours after the last meal. When that glycogen has all been used up (usually around the 16 hour mark), the body then begins to burn your fat reserves as a source of energy. Do this often enough, your body becomes more efficient at ketosis (fat burning) and you lose weight.
So why fast?
1. Weight loss
The reason many people come to IF in the first place, is weight loss. Made popular by diets such as the 5/2 Fast Diet by BBC presenter, Dr. Michael Moseley and The Every Other Day Diet by Dr. Krista Varady, these diets have gained a lot of press and now entered the mainstream. There are now more books available and more ways to introduce fasting into your life to suit the way you live and your health goals. These include doing longer multi day fasts (less often), having a ‘window’ of time like 5 hours you eat each day, or fasting most of the day and eating just one meal a day (OMAD).
2. Improve your blood markers
Blood markers are the levels of hormones, enzymes, nutrients and other chemicals in the blood that affect your health. One of the most important benefits of fasting is lowering blood sugar and increasing insulin sensitivity. Why is that important? If you have high blood sugars and are insulin insensitive (otherwise known as Insulin Resistant), you have a hard time using your stored fat as a fuel source. Your hormones are signalling to keep eating to keep your blood sugar high to feed the beast and high insulin levels means your body will be a lot less efficient at burning your stored fat.
Other health benefits and improved blood markers resulting from fasting include lowering of blood pressure, cholesterol and lipids, all of which are important to lower your risk of heart disease.
3. Type 2 Diabetes prevention and treatment
Fasting is now being used successfully as a treatment for Type 2 Diabetes, a chronic condition wherein the body becomes less and less sensitive to insulin resulting in a whole host of health problems. Diabetes is often seen in conjunction with obesity and/or poor diet. ‘Diabesity’, obese people with Type 2 Diabetes, is becoming more and more common and in younger people. Clinicians such as Dr. Jason Fung in Toronto Canada have had great success using fasting to treat patients with Diabesity including getting them to lose significant amounts of weight and off all medications and reversing their Diabetes. Type 2 Diabetes (as opposed to Type 1 Diabetes which you are born with), is a serious and extremely debilitating disease if not managed. Many overweight and obese people have metabolic syndrome or are ‘Pre-Diabetic’ and don’t even know it. That means they are becoming less sensitive to insulin as time goes on and at high risk of developing Type 2 Diabetes if they don’t make diet and lifestyle changes as soon as possible.
4. Autophagy (cell regeneration)
Autophagy is when the body breaks down and ‘eats’ old dead cell parts that are no longer required. Fasting stimulates this process by stimulating a hormone called Glucagon, which signals to the cells its time to get rid of the old junk. Fasting also stimulates Growth Hormone, which is critical for regenerating new cells in the body. The studies around autophagy and anti-aging, Alzheimer’s prevention and cancer are promising. Another study found 2-4 days of fasting may even "reboot" the immune system, clearing out old immune cells and regenerating new ones - a process they say could protect against cell damage caused by factors such as aging and chemotherapy.
5. Reducing inflammation and improving gut health
Research from Yale University also shows that fasting produces a compound that reduces inflammation in the body. This has several promising indications for treatment of autoimmune diseases, Type 2 Diabetes, Alzheimer’s, atherosclerosis, and autoinflammatory disorders.
Many fasters anecdotally report clearing up of skin problems, thesettling of IBS symptoms (Irritable Bowel Syndrome) and even reduction in arthritic symptoms after fasting. Studies have shown that fasting can improve the balance of good bacteria in your gut, thereby improving your immune system and switching on that important inflammatory response. Further research into the promising effects of fasting, particularly as it related to human microbome (your overall gut health) are required.
There are different ways to fast, it is not a one-size-fits-all miracle cure, you need to find the right program based on what your health or weight loss goals are and what your body responds well to (I know, hunger is not one of those things that anyone responds well to but trust me, you WILL get used to it and it's worth it). Read my Guide To Intermittent Fasting here.