|The Health Benefits of Intermittent Fasting |
I came across the concept of intermittent fasting (IF) through a colleague of mine, Dr. G.H.Moore, about a year ago. The concept of fasting on alternate days is based on the belief that our hunter/gatherer ancestors probably did not eat three square meals a day and very often would go a day or longer without food - or at least protein-rich animal foods. Our biochemistry had to evolve to accommodate this reality and must have benefited from it or we would not be here today.
Fortunately there has been an enormous amount of research on the health benefits of IF and several human studies on IF supporting the theory that there are many health advantages to following an IF program.
The Biochemistry of IF
1. Cortisol is a stress hormone. IF has a cortisol lowering effect. Cortisol chops up lean muscle mass. Cortisol levels drop markedly with the shift to once daily eating. Anything that drops cortisol levels is good.
2. BDNF (brain-derived neurotrophic factor) is the substance that the brain secretes to grow new brain cells. Intermittent fasting (IF) increases BDNF.
3. Intermittent fasting not only makes you leaner, but stronger, thanks to the human growth hormone (HGH) increases during IF.
4. Insulin levels come down during IF. while both glucagon and human growth hormone go up.
5. There were significant reductions in interleukin-6 (IL-6), C-reactive protein (CRP) and homocysteine during the fast that, in the case of IL-6 and CRP, lasted for at least 20 days beyond the fasting period. IL-6 is a pro-inflammatory substance released by macrophages and other inflammatory cells that reaches the circulation and ultimately the liver. Both IL-6 and CRP are elevated during inflammation, and both, but particularly CRP, are used as markers for inflammation. There is now a large amount of data showing that elevated CRP levels are a potent risk factor for cardiovascular disease.
There are numerous ways to apply the principles of IF to accommodate your lifestyle.
One simply way to do it that I've used is to follow a plan as such:
Day 1: eat three meals a day finishing by around 6 pm
Day 2: fast on water with lemon or lime juice or electrolytes added to it from morning until close to 6 pm that day. Eat a healthy dinner
Day 3: Repeat cycle.
Variations of this plan could include just skipping breakfast or lunch on day two, but for the maximum health benefits from IF it is best to have as close to a 24 hour period of no eating as possible.
Here are the key dietary principles to apply to an IF plan:
- Avoid all hydrogenated fats and processed foods. Sugar is the enemy to accomplishing your health goals.
- Your diet should revolved around high quality protein foods such as meat, poultry, fish, eggs and cottage cheese; vegetables, raw nuts and seeds (soaked in water overnight is optimum), high quality fats such as olive oil, butter, avocados and coconut oil.
- Eat fruits ,grains and beans sparingly.
- Eat when hungry - listen to your body. If you are hungry on a fast day try your best to make it to 6 pm before eating, but if necessary eat light as late in the afternoon as possible.
- Since you never go a whole day without eating you will not be malnourished, the key is to periodically rest your digestive system from working so hard.
- Make sure you drink plenty of pure water with sufficient electrolytes especially on your fast day, this will stabilize your blood sugar.
My own experience with If is limited to a one month period I did it about 6 months ago. I loved it, but switched back to my normal eating habits during a time of stress when I was moving. I am bringing IF back this month and want to encourage my clients who are receptive to give it a try.
I thought my blood sugar would be destabilized without eating frequently. I was wrong. As long as I drank enough water with electrolytes in it I was fine. It is important to eat as much healthy food as you want when you do eat since this is NOT a calorie restricted program.
We as a species have a genome that was molded by the forces of natural selection. If you buy into the idea that the Paleolithic diet is the optimal diet for us today (the diet we were molded by the forces of natural selection to perform best on), then you should probably also buy into the idea that a meal timing schedule more like that of Paleolithic man would provide benefit as well. Our pre-agrarian ancestors were compelled to eat on an availability, not a preferential basis. They did not get "three squares" each day. And they were vibrantly healthy.