In the past, I’ve touched on the subject of fasting. Since then, I’ve noticed that the conversation surrounding this new approach to “dieting” has continued to heat up.
It’s an interesting concept–one that tends to go in and out of “fashion” over time. And it looks like it’s enjoying yet another heyday. Fasting is in vogue amongst the thin elite once again.
So I thought I’d take some time today to revisit the topic–and more specifically, to look at the science behind fasting and how it affects those with obesity and diabetes. (Two groups who could vastly benefit from more efficient methods of dropping weight.)
I’d also like to address some of the misconceptions currently held about what I think is actually a very effective way to boost your health. Because contrary to popular belief, fasting really isn’t about fitting into size 0 clothes. (Not that there’s anything wrong with that.)
First, let’s get some definitions out of the way.
Intermittent fasting (IF), in this context, is fasting for 24 to 48 hours on consecutive or alternating days. Modern animal research suggests that fasting periods like this can boost longevity and health while combating disease. (Really, though, the benefits of this technique have been touted for the better part of a century.)
Intermittent fasting can work in a number of ways. Usually, it simply involves alternating days of “normal” calorie intake with days of severe caloric restriction. (That is, fewer than 600 calories for men, and fewer than 500 calories for women.)
A newer iteration of the IF strategy relies upon a 5:2 approach–where any two days in a single week are fasting days. But ultimately, it’s the same basic idea that’s always been around.
In fact, many of my patients would recognize this as a technique I employ in people who are stuck at a certain weight or who have “plateaued.” (It’s also a technique I have been using for 20 years now.)
But you’ll have to pardon the pun and trust me when I say that intermittent fasting has weightier applications, too.
Most notably, research indicates that IF is at least as effective (if not more so) than less aggressive, but continuous calorie restriction when it comes to weight loss and insulin sensitivity–not to mention a whole host of other health markers.
Like inflammation levels, for example. Or circulating glucose, cholesterol levels, and blood pressure. Most studies show that IF can positively affect all of these factors… all while boosting your metabolism and cutting oxidative stress.
So it’s no surprise that research on animals points to intermittent fasting as a potential foil for type 2 diabetes–one that can improve insulin levels and sensitivity, while warding off diabetic complications.
This is especially important if you have pre-diabetes. Pre-diabetic people have impaired glucose tolerance or impaired fasting glucose. This is signified by HbA1c levels above 5.7. If your doctor hasn’t run this test, then request it.
If your results are abnormal, please take this wake-up call very seriously. It means you’re also at risk for developing early heart disease, and all the complications that come with it.
The sooner you deal with this problem–preferably by cleaning up your habits and losing some weight–the better. And if fasting can put the brakes on pre-diabetes put you on the fast track toward better heart health, I see no reason not to embrace it.
Honestly, what more could you want in any eating program?
Unfortunately, I expect that IF will continue to struggle with the same image problem it’s always had. This dietary approach is easy to dismiss as a fad starvation diet. Despite its clear benefits.
That won’t stop me from promoting it, though. I’ve always recommended short fasts to my patients as a simple and effective form of detox. I even fast once a month myself.
Because an occasional day or two of temporary calorie restriction won’t kill you. But diabetes will.
“Intermittent fasting: a dietary intervention for prevention of diabetes and cardiovascular disease?”British Journal of Diabetes & Vascular Disease. 2013;13(2):68-72.