Intermittent Fasting Can be a Good Way to Lose Weight & Improve Health

If you read health magazines or watch shows that discuss weight loss, you have probably heard the new craze of Intermittent Fasting (IF). Basically, there is no real definition for IF, and many health experts, doctors, and book authors define it differently. I, personally,  define fasting as not eating or drinking anything besides water for at least 24 hours.

I am okay with people fasting since I think it is a natural process that the human body is meant to deal with.  A lot of how our body stores fat and how the metabolism works is attributed to our genetic makeup tracing it back to our ancestors. These people typically went through days where they consumed adequate calories, then some days where they had very few calories. Therefore, the need to store fat and conserve energy was important for survival. So, IF seems like a sensible thing for dieters to try since we seem to be going against our own genetic makeup by eating all day 24/7. I also think it is good for people to experience hunger, and have your body go through all the anabolic and catabolic metabolic pathways (glycolysis, gluconeogenesis, lipolysis, etc.).

According to some studies, IF may accelerate weight loss, decrease inflammation, blood pressure, cholesterol, and decrease the risk for cognitive decline, heart disease, and certain cancers. However, improving insulin sensitivity seems to be a benefit that is seen across most of the IF study subjects.

My Recommendation: I only recommend IF for those people that don’t have diabetes, hypoglycemia, or any health condition that would contraindicate IF. I basically only recommend IF to those people that know they do not exercise 2 days out of the week and are unwilling to, and know that they can go long periods of time without eating and not pass out. I would rather people exercise every single day (yes, even on "off" days go for a brisk walk or do yoga!) and eat normally than be sedentary and only eat a few hundred calories. But, if you know you will not exercise on certain days, use those days for IF.

Furthermore, I only recommend IF for people who have strong willpower- the last thing I want is someone binging at night because they haven't eaten during the day and have such strong cravings that they end up eating a tub of Ben & Jerry's at night. I also don't encourage people to use IF as an excuse to eat crap during the days they are not fasting, because you will most likely not see the health or weight loss results you want. 

I, personally do not practice IF due to the fact that I am very active and it would be unwise/unhealthy to limit my calories to <600 on any given day. However, IF can be a great tool if you are trying to lose weight and have good self control. I recommend Dr. Michael Moseley’s approach which requires you to consume <600 calories two days out of the  week. If you are trying to lose weight and stick to a well-balanced 1500 calorie diet the other 5 days/week, you should technically lose about an extra half pound per week. On the days that you are eating <600 calories, I recommend loading up on fruits and vegetables since you can eat a high volume for few calories. It is also important to include lean proteins and whole grains and drink TONS of water. 600 calories can be a substantial amount of food if you are choosing the right foods! 

So, again, I don't really define this as fasting, I would say it is more Intermittent Extreme Calorie Deficit (IECD- you heard it hear first!). You can choose any two days out of the week you want, but those are the ONLY 2 days out of the week that you aren't getting a good workout in (being physically active is CRUCIAL to living healthy!).

References:

Proc Natl Acad Sci U S A. 2003 May 13;100(10):6216-20. Epub 2003 Apr 30.; http://www.bbc.co.uk/programmes/b01lxyzc

 Med Hypotheses. 2006;67(2):209-11. Epub 2006 Mar 10.

 J Nutr. 2003 Jun;133(6):1921-9.