Day 3 of my fast and I’m surprised how easy it has been so far. I woke up this morning and for the first time in at least 15 years I actually felt awake and refreshed. This feeling only lasted for about an hour but it was really nice to feel that again. I did cave and have a black coffee today. Oh man, it made me so happy for about 15-20 minutes. Then the brain fog descended and I felt like I was wandering around in a haze for the rest of the day. I also fluctuated between feeling very tired and feeling energised throughout the day. And the hunger pangs started this afternoon, which I’m thinking may have been due in part to the coffee. Coffee in the past has made me feel weak and shaky (probably messing with my blood sugar levels) so lesson learned and no more coffee until the fast is over.
Today I decided to look at what happens to our physiology when we go into the fasting state. There are so many different ideas about it and whatever angle you look at, you find research to back that opinion. I believe that humans are all individual and while we all have similar physiology, it is my opinion that we all have our little physiological/biochemical quirks and thus respond differently. So here’s the basics of what happens when we are in a fasting state:
*Phase One (roughly 6-24 hours after eating):
- When food is not longer being consumed (therefore no glucose), insulin levels start to fall.
- The body breaks down glycogen that is stored in the liver and converts this to glucose.
*Phase Two (24hours – 2 days of fasting):
- As glycogen stores deplete, the body starts to make ‘new’ sugar (a process called gluconeogenesis) from sources such as lactate and amino acids (from muscles).
- The brain and body continue to rely on glucose as an energy source.
- The body starts to synthesise fat.
*Phase Three (2-3 days of fasting):
- Low insulin levels cause the body to simulate ‘lipolysis’ which is the breakdown of fat to form fatty acids.
- Fat is broken down into glycerol and and three fatty-acid chains (lipolysis).
- Glycerol is used in gluconeogenesis (‘new’ sugar production). The fatty acid chains are used for energy and also in the formation of ketones, which the brain uses as energy.
*Phase Four (approximately 5 days + of fasting)
- Could be called the ‘protein conservation’ phase.
- Growth hormone increases thus helps preserve lean muscle tissue.
- The body gets its energy from the fatty acids and ketones.
- Increased noradrenalin levels help prevent decrease in metabolic rate.
*From Dr Mark Korson http://fodsupport.org/documents/ThePhysiologyofFastingandFODs.pdf
Obviously, there is a lot more complicated physiology behind fasting and I am by no means an expert. If in doubt, do the research yourself. But what blew me away when reading about the physiology of fasting was the countless sources that said fasting DOES NOT decrease metabolic rate. In fact, in some instances it has been shown to increase it. Huh???? Haven’t we been told that low calorie and fasting decrease metabolic rate and that’s why you whack the weight on after doing things like this? Now I’m curious where the myth of a slowed metabolism comes from. I will keep you posted on this as I find out more information.
Of course, there is a difference between starvation and fasting. Starvation occurs when fasting is taken too far and the body no longer has the fat reserves to produce energy. This is when the body starts to break down other tissue to survive i.e. muscle. So be sensible about fasting people and listen to what your body is telling you. Make sure you have a support crew around you if embarking on a fast that lasts a few days. Also make sure you’re in contact with a couple of health practitioners to help guide you through it so you stay safe.