Intermittent Fasting: The Basics
(Please note: skip to the 6th paragraph for the non-boring stuff)
It is safe to say that intermittent fasting is not just a new fad diet. It has been around for decades in nutritional science communities and forms of it have been around for centuries. Now, it is pretty safe to say it is a main stream concept that every demographic seems to be picking up from the stay at home mom or dad to celebrities and even some physicians.
So what is intermittent fasting? Basically, it just means you fast for a specified period of time and eat for a specified period of time. There are 3 main forms.
First, there is alternate day fasting which means you eat one day and don’t the next. This has been researched numerous times and is shown to have a bunch of positive benefits. Lower cholesterol (the evil LDL kind), and a decrease in cancer risk factors and inflammatory markers.
Second, there is a calorie restricted diet with a 5:2 ratio meaning you eat normal for 5 days a week and you restrict calories to 20-25% 2 days a week. This form is also shown lower cholesterol and inflammatory marker. However, this is also shown to decrease weight more significantly as well as lower fasted plasma insulin levels.
The issue with these two types is that there is no significant change in weight loss (at least consistently shown throughout all the studies) and there are significant psychological side effects. They cause a poor mood, mood swings, anger, fatigue, low energy levels, and other not so great things.
Finally, there is the more well known and more practiced form which is time restricted intermittent fasting. This is the form where you fast for 12-20 hours each day and eat a normal caloric amount during the other 4-12 hours. There have been a ton of studies done on this form of intermittent fasting (mostly on mice) that have led to repeatable conclusions. Decrease in weight, cholesterol, triglycerides, fasted plasma glucose, and fasted plasma insulin. Additionally, it led to an increase in insulin sensitivity which means it could help someone with diabetes or hyperglycemia. Furthermore, the rats who were put on a time restrictive fasting diet and fed equal caloric amounts were almost impervious to obesity, inflammatory issues, hyperinsulinemia, and hepatic steatosis.
Human studies done on time restrictive intermittent fasting have shown significant decreases in weight loss (1.3%-4% after 2-8 weeks) and came with little to no side effects. Participants would report hunger, but there were no changes in mood and no signs of fatigue.
Lastly, and this maybe the most important detail about time restrictive intermittent fast or just fasting in general, it induces cell autophagy. Autophagy simply means cell death. This is important for a variety of reasons. First, it helps get rid of cells that are mutated or just old. Think of it as a spring cleaning every time you fast. Second, autophagy from intermittent fasting is a great secondary treatment for cancer. Patients put on an intermittent fasting protocol during chemo and radiotherapy show significantly better results in terms of stagnating tumor growth or remission. I would never say that diet alone is an effective way to treat cancer, however, it is a great additional treatment to work collectively with traditional therapies to better results.
Intermittent fasting has much more complexity to it, however, this is the basics. In later article we will dive into ketosis and energy metabolism as a result of intermittent fasting as well as longer fasts like 3+ days and the effects of that. For now, I hope this shed a bit of light on intermittent fasting, and please leave your thoughts below.