Last week, I wrote a post outlining my thoughts on the KETO craze. I received several comments and feedback, along with some questions about other diets and eating trends.
Based on that feedback, today I’m tackling the subject of Intermittent Fasting (further in-text – “IF”). Over the next couple of posts I will discuss the following aspects of “IF”:
- What it is
- What it’s not
- Different types
- The benefits
- What the clinical research says (with links)
Let’s start with a simple definition.
“IF” is a pattern of eating that cycles between periods of feeding (eating) and fasting (no eating).
The great news is you already do this every day! (you aren’t eating while you sleep)
Specific “IF” protocols modify the length, timing, and frequency of the feeding and fasting phases. There are many different variations and opinions on which “formula” for feeding/fasting works best.
I will discuss those later, but first, it’s important to highlight what “IF” is NOT.
Intermittent Fasting is NOT a weight loss strategy!
Despite being the most popular reason people do “IF”, research has NOT shown that “IF” improves weight loss. Compared to regular dieting protocols (daily caloric restriction), or just regular healthy eating!
Many people do lose weight when they start “IF”. But it’s not typically due to the IF protocol itself.
Many “wack-jobs” are out there promoting crazy diets, cleanses, and fasting as extreme “cures” for all kinds of ailments. The majority are ridiculous and many are dangerous.
Keep in mind that “IF” has not consistently proven to work better than a sensible, healthy, nutrition program combined with regular movement and exercise.
Sensibly implemented “IF” can be a helpful part of these plans, while providing numerous additional benefits. Sensible “IF” can be a helpful part of these plans.
More on that later.
Intermittent Fasting is NOT a license to eat crap and then occasionally starve yourself.
People often use “IF” for calorie restriction. While this can lead to weight loss (like dieting), some people “reward” and overcompensate from their fasting phases by overfeeding when they aren’t fasting. Or simply by eating low-quality food. Remember that a healthy nutrition mindset and plan combined with regular movement and exercise are essential to long-term health and performance.
Intermittent Fasting is NOT a one-size-fits-all approach – EVERYONE IS DIFFERENT!
We all have different work & life schedules, genetic variations, metabolic types, preferences, and psychological make-ups. These all influence how “IF” will impact us and is best applied (if at all).
The Benefits of Intermittent Fasting:
Unlike “dieting”, “IF” can be beneficial when done correctly and has many well-documented benefits to health and performance. Here are a few:
- Lower insulin levels
- Decreased blood pressure
- Greater insulin sensitivity
- Increased cellular repair processes (Autophagy)
- Increased Human Growth Hormone production
- Greater ability to utilize fat for fuel
- Positive changes in gene expression
Unfortunately, most people aren’t interested in “IF” for those reasons. For these people, it’s (mistakenly) about weight loss.
Also, a recent study (March 2024) of 20,000 people published by the American Heart Association shows that Intermittent Fasting using an 8 hour feeding window (16 hour fast) increases risk of cardiovascular death by 91%. This is a massive negative impact and something to strongly consider if you are thinking of doing intermittent fasting.
Senior study author Victor Wenze Zhong, Ph.D., a professor and chair of the department of epidemiology and biostatistics at the Shanghai Jiao Tong University School of Medicine in Shanghai, China notes:
“We were surprised to find that people who followed an 8-hour, time-restricted eating schedule were more likely to die from cardiovascular disease. Even though this type of diet has been popular due to its potential short-term benefits, our research clearly shows that, compared with a typical eating time range of 12-16 hours per day, a shorter eating duration was not associated with living longer,” Zhong said.
Done properly, Intermittent Fasting requires an important mindset shift.
Success with “IF” (and every other healthy nutrition program) requires getting past the urge to count calories, “restrict” your food intake or pleasure, or “make up” for poor eating habits by avoiding food.
“IF” is one of many actions you can take to experience some health benefits. More importantly, it helps you tune into your body’s responses to all of the daily processes that are happening within and around you. This includes your response to food, sleep, digestion, elimination, exercise, and much more.
To their detriment, most people do not pay attention to these things. Consequently, they are unable to harness them for improvements in all areas of life.
This concept is at the heart of my coaching philosophy and what we work with people at FRESH! To master.
In my opinion, one of the biggest and most underrated benefits of IF is to remind our bodies what it’s like to be hungry.
In first-world countries, most people have forgotten what it’s like to be hungry. Few people reading this are struggling to put food on the table. They can eat what they want when they want.
This is a good situation to be in, but there are also downsides to it. “IF” can help with some of these, but not all.
I would be remiss if I didn’t point out the obvious downside of choice, and something “IF” doesn’t impact. That is the quality and type of foods we choose. Sometimes people make choices that aren’t in their best interest. We see this every day with food.
Most first-world residents can choose foods that energize, honor, and heal their bodies, yet they regularly choose foods that dishonor, deplete, and harm them.
Changing the timing of your foods won’t impact the quality and quantity of the fuel you put in your body.
The timing of meals (the variable in IF) is just one piece of the overall puzzle. It’s important, but not the entire picture.
If weight loss happens, people attribute it to “IF” rather than the change in their food habits, portion sizes, etc.
As mentioned, studies show that outcomes from “IF” aren’t any better than healthy eating and exercise. Reputable “IF” protocols call for healthy eating and regular exercise as part of the protocol.
Healthy eating and regular exercise aren’t things most people do. So, they will see weight loss and health improvements when they start doing it!
This is the same with virtually ALL “diet” protocols. They work when you follow them, but the nature of a diet is that you “stop” dieting when you reach your goals. This doesn’t make any sense and is a key issue at the root of our modern “diet culture”.
People see some new diet trend come up and think…” hey, what I’m currently doing isn’t working, so I should try this new thing for a while to see if it works.” In other words, they replace their daily unhealthy habits with something that’s (hopefully) more beneficial.
Of course, they see results while they follow the plan! The problems come back when they stop doing what got them positive results in the first place. Or when their new plan is unrealistic or unsustainable.
Back to where Intermittent Fasting is POTENTIALLY beneficial.
Humans are diurnal creatures. We evolved to live off circadian rhythms (light/dark cycles). Our hormones, energy, and body systems are still tied to these circadian rhythms. It’s one of the reasons shift workers, those who stay up late, and chronically sleep-deprived people have more health problems.
Our food intake and cellular processes are also on this cycle. “IF” is a great way to live into the rhythms that our bodies evolved from.
As mentioned, under normal circumstances, most people “fast” every night when they sleep. The challenge for the majority of modern society is that we stay up too late and don’t get the rest and recovery our body needs.
Many of the fasting regimens I will discuss later are simply a way of getting our nutrition timing on a more sensible schedule. Others are just excessive and unjustified (IMHO).
That’s enough to get you thinking for today.
We know that “IF” has some great benefits, that our body is evolutionarily set up for this type of eating schedule (at some level). But also we know that most people use “IF” for the wrong reasons.
In the next post, I will discuss the most common methods of “IF” and some of the pros/cons of each. I will also provide you links to some current research articles should you wish to peruse the science in more detail.
Read Part 2 of this Intermittent Fasting post by clicking here!
Let me know your thoughts and if there are specific aspects of “IF” that you want me to address.
If you are interested in more information about a healthy diet, make sure to check out our Fuel Your Body For Success course!
Sources:
- https://www.health.harvard.edu/blog/intermittent-fasting-surprising-update-2018062914156
- https://jamanetwork.com/journals/jamainternalmedicine/fullarticle/2623528
- https://www.ncbi.nlm.nih.gov/pubmed/29951594
- https://www.ncbi.nlm.nih.gov/pmc/articles/PMC329619/
- https://www.ncbi.nlm.nih.gov/pubmed/1548337
- https://www.healthline.com/nutrition/intermittent-fasting-and-weight-loss#section1
- https://www.healthline.com/nutrition/intermittent-fasting-guide#weight-loss
- https://www.sciencedirect.com/science/article/pii/S193152441400200X
- https://www.health.harvard.edu/blog/intermittent-fasting-surprising-update-2018062914156
- https://jamanetwork.com/journals/jamainternalmedicine/fullarticle/2623528
- https://www.ncbi.nlm.nih.gov/pubmed/29951594
- https://www.ncbi.nlm.nih.gov/pmc/articles/PMC329619/
- https://www.ncbi.nlm.nih.gov/pubmed/1548337
- https://www.healthline.com/nutrition/intermittent-fasting-and-weight-loss#section1
- https://www.healthline.com/nutrition/intermittent-fasting-guide#weight-loss
- https://www.sciencedirect.com/science/article/pii/S193152441400200X
- https://newsroom.heart.org/news/8-hour-time-restricted-eating-linked-to-a-91-higher-risk-of-cardiovascular-death
