Is Intermittent Fasting Backed by Science?

By Dietitian Jill AKA The Queen of Leaky Gut

I began doing intermittent fasting (IF) about 6 weeks ago.  And by the fourth had lost 7 pounds.  Eating what I wanted … even birthday cake.  And drinking wine to boot.  But, being a clinician, a thought had always nagged me. Is this all backed by science?

I supposed it was.  As our metabolism isn’t really much different  than Neanderthal man’s.  Who was used to gorging on the wild boar. Or the berries he found along the way (fruit was a lot more starchy then). And then not eating … sometimes for many days … when hunting and foraging for food failed.

We actually didn’t have access to a steady food supply until the agricultural revolution … the first one occurring about 10,000 years ago.  To explore the influence of meal frequency and timing in human history, read the research here. 

I hadn’t  really researched intermittent fasting’s benefits until today.  Here’s what I found …

First … Intermittent Fasting Defined

If you don’t know what IF is … David Katz, MD, calls it a fancy way of saying “skipping breakfast”.  Pure and simple, it’s eating within a certain time frame EVERY DAY … say within 8 hours. And NOT eating the rest of the time (yeah … you can have coffee, tea, other sugar-free beverages … and LOTS of water).

So … in reality … it’s less like “fasting” … which to me conjures up the extended times (last one … 10 days)  I’ve gone WITHOUT food … drinking water only at Dr, Alan Goldhamer’s True North Health … one of the few fasting centers still around as it’s staffed by Chiropractors, ND’s, and MD’s.  And more like “skipping breakfast”.

Which I myself did as breakfast foods have never had a huge allure for me.  And also I’ve been able to narrow my time frame comfortably … and effectively … to 6 hours a day.

And who knows where I will go next!  Perhaps to the “Warrior Diet”, which narrows the eating window even more to one meal and 4 hours a day.

But I’m OK with where I’m at right now.  My Health Self-Experiment (click here to find out how I set up my own Health-Self-Experiment … and launched an idea now trending on Pinterest) was a success.  So I’m stickin” to it!

But I was happy to know … and appease my clinical side … that there IS scientific backing for intermittent fasting …

Intermittent Fasting Burns Fat, Not Sugar

When you don’t eat for a period of time (research says as early as 10 hours with a major shift happening at 18 hours), you begin to burn fat as fuel.  Carbohydrates (starches and sweets) are preferentially burned first.

So if you’re eating all day, you’re not burning fat as readily as you do when you do IF.  And, when you’re burning fat (exercise helps to burn fat and boost metabolism even more), you’re losing weight.

Not only that, if you’re only fasting 10 to 18 hours a day, you’re PREFERENTIALLY burning fat.  Because the body can also break down proteins for fuel … (we burn carbs first, then fat, then … as a last resort … protein).

But that doesn’t happen until about the third day of fasting. So IF can help you lose weight while still maintaining your muscle mass. In other words …

IF Helps You Lose Weight

Burning fat is not the only way, however, that IF helps you lose weight.  Years ago, when I was working for Harvey and Marilyn Diamond of Fit For Life fame, someone said a very profound thing (it was possibly Harvey as he was a profound speaker).  “When you eat fruit in the morning, you’re cutting out a third of your calories!”

So … pure and simple … if you “skip breakfast”, you’re eating less.  Which … obviously … will help you lose weight. Unless you’re gorging yourself within your eating window.  Which I never feel the inclination to do.

Additionally, intermittent fasting enhances hormone function, lowers insulin production, and increases secretion of growth hormone and noradrenaline.  In lay terms, all of these break down body fat more easily so it can be used for energy.

Studies have also shown that IF increases our metabolic rate by 3.6-14%.  So IF then becomes a double threat by upping your metabolic rate (more calories out) and lowering the amount of food you eat (less calories in).

According to a 2014 review of the scientific literature, IF can produce a weight loss of 3-8% over 3-24 weeks.  That’s more than I’ve ever seen in other studies using traditional methods.  And explains my own dramatic weight loss.

In the same review, subjects also lost 4-7% of their belly fat.  Which has been widely researched to cause life-threatening things like heart disease …

IF May Reduce Heart Disease Risk

Intermittent fasting has been shown to improve numerous heart disease risk factors, including blood pressure, total and LDL cholesterol, blood triglycerides, inflammatory markers and blood sugar levels

Not only does LDL (AKA low-down-lousy cholesterol) decrease by about 25 percent after eight weeks for those on IF, but even better, we actually see a decrease in small LDL particles. An increase in small LDL particles is a much more vital indicator of risk than LDL itself.

Thus, IF decreases both total LDL and dense LDL particles. Also, levels of triglycerides, the fats present in the blood, can dip as much as 32 percent.  The same study also noted no significant decrease in HDL … the good cholesterol.

A lot of this research, however, is based on animal studies. The effects on heart health need to be studied a lot further in humans before actual recommendations can be made.

IF May Improve Brain Health

There is some compelling research that IF may lead to a decrease in nerve dysfunction and degeneration, meaning that it may be beneficial for conditions such as Alzheimer’s, Parkinson’s, and Huntington’s diseases.

Several studies (here’s one) in rats have shown that intermittent fasting may increase the growth of new nerve cells, which should have benefits for brain function . It also has been shown to increase levels of a brain hormone called brain-derived neurotrophic factor (BDNF), a deficiency of which has been noted in depression and other brain problems.

Animal studies have also shown that IF protects against brain damage from strokes. Unfortunately, most of these are … again … studies with animals … so more research … and obviously more human trials … need to be done to confirm all this.

IF Reduces Inflammation

Inflammation is the byproduct of leaky gut and the cause of all health problems (check out my article, What IS Leaky Gut?, for a whole list).  Inflammation  occurs when free radicals, reactive molecules, smash into other important molecules (like protein and DNA) and damage them.

Normally, we can keep this damage under control.  But, with the onslaught of food, toxins, and ongoing life stressors today, our bodies find it more and more difficult to do this job. So just removing one may be an easy way to decrease inflammation.

One study showed that NRLP3 inflammasome, an inflammation marker,  decreased with IF. Another noted that intermittent fasting may increase the body’s resistance to oxidative stress.

IF, therefore, may be a way to decrease inflammation and actually prevent chronic disease.  Of course, more research needs to be done to affirm these many links and suppositions.

Me … I’m just happy with my weight loss.  And looking forward to that reduction in belly fat!  How about you?

Want to try an intermittent fasting self-experiment like I did?  Here’s your chance!  Click here to schedule a Let’s Talk HEALTH session with me.  What are you waiting for … START TODAY!