What Exactly is Intermittent Fasting?

Intermittent Fasting (commonly referred to as “IF”) has recently garnered a lot of press in the fields of health, nutrition and weight loss. However, like every “dietary trend” that gains traction, there is always nearly an overabundance of information to sort through making it difficult to know “whether or not it’s good for me”. I’m going to take a moment to break it down, explain the various types, and highlight some of the incredible evidence-based health benefits that can be gained from this way of eating.

1) What exactly is intermittent fasting and why is it so popular?

By definition, IF is a dietary plan which requires alternate periods of fasting and eating in order to lose weight/body fat, lower risk for certain diseases, or improve various metrics of one’s health.  It has become increasingly popular over the past few years not just because of the countless celebrity endorsements, but rather because it works, does not require a significant change in what you eat, and allows for a great deal of flexibility. For instance, IF does not involve counting  calories or macros, nor does it require the elimination or restriction of any particular food or food group. Additionally, there are several intermittent fasting schedules that one may choose to follow so it allows for a great deal of flexibility, can easily be incorporated into a busy lifestyle, and helps people feel in control of their way of eating.

2) What are the six different IF methodologies and how do I choose the one that’s right for me?

-The 16/8 or 14/10 Method: This schedule requires daily fasting for 16 hours for men and 14 hours for women.  You will eat two or three (healthy) meals plus any additional snacks within an 8 or 10 hour window, although water, coffee and other beverages lower than forty calories are permitted throughout the day. This method is often popular with people who don’t usually wake up hungry or may naturally skip breakfast anyway.

-The 5/2 Method (or “Fast Diet”): This schedule involves eating a typical diet five days of the week and restricting calories on the remaining two days (500 for women and 600 for men).  The restricted calories are divided into two meals of 250-300 calories each.

-Alternate Day Fasting (ADF): This schedule involves alternating days between a typical day of eating and a 500-calorie day. This is an extremely effective method in the short term to reach a specific goal, but can be difficult and unpleasant for many people so likely not sustainable beyond a few weeks.

-Eat-Stop-Eat: This schedule requires a full 24-hour fast in between two days of “regular” eating. For instance, if you finish dinner at 8pm on Sunday, you wouldn’t eat again until 8pm on Monday (although water, coffee and tea are permitted during the fasting period). However, much like ADF, this is not an optimal method for most people in the long term. A full 24-hour fast is physically very uncomfortable and requires major self-discipline.

-Warrior Diet: This schedule involves eating just small amounts of fruits or vegetables during the day, and “feasting” on one large meal in a 4-hour window at night. This method is often popular amongst people that work long hours or are constantly on the go/traveling during the day and rarely have time to eat a proper breakfast or lunch anyway.

-Spontaneous Meal Skipping: This is definitely the most flexible method, and for most people the easiest to commit to long term (because it actually doesn’t require any commitment!). The spontaneous method simply involves just skipping meals from time to time when you aren’t hungry, are on-the-go and don’t have a chance to eat, or are simply too exhausted to cook. It’s a myth that humans need 3 square meals a day – it’s not at all how our ancestors lived or how our bodies are designed, and we are actually quite capable of surviving and thriving during intermittent fasts.

 All of these methods appear to yield equally impressive results when practiced in combination with a healthy lifestyle; however, results obviously vary from person to person and what often matters most is finding a schedule that works for you.

3) So, in addition to weight-loss, what are some of the other benefits of IF?

• Facilitates belly fat loss and boosts metabolism: By practicing IF, you will generally consume less food overall (decreased “calories in”) while also ramping up your metabolic rate (increased “calories out”). Intermittent fasting also helps to lower insulin and raise growth hormone and norepinephrine. Together, this promotes the breakdown of body fat and helps the body effectively use it for fuel.

• Reduces inflammation and oxidative stress: Numerous studies show that IF helps slow the visible signs of aging and lower one’s risk of chronic disease.

• Helps induce cellular repair: Intermittent fasting assists our cells in stimulating “autophagy” (a waste removal process) which may help protect against cancer, and neurodegenerative diseases such as Alzheimer’s, Parkinson’s and Huntington’s.

• Improves various risk factors for heart disease: IF may benefit overall heart health by lowering LDL and total cholesterol, blood pressure, blood triglycerides and blood sugar levels, as well as possible other inflammatory markers. 

• It’s good for brain health: Studies show IF may stimulate the growth of new nerve cells which help improve neural function, and reduce risk of stroke. Additionally, IF boosts the levels of BDNF, a hormone essential for preventing depression and other mental illnesses.

More research certainly needs to be conducted on intermittent fasting, but our point of view is that it is very possible it can help you live a longer and healthier life with very little risk or downside. Ideally we recommend our clients follow either a “Spontaneous Meal Skipping” or “14/10” schedule primarily because of the flexibility they offer and the ability to sustain these patterns long term. However, we also recognize everyone is unique and results may vary greatly from person to person. If you’re interested in giving it a try yourself, please speak with your physician first and then experiment to discover the method that works best for your bio-individuality and lifestyle.