Might be of interest to some...
I recently came across a great new paper in the New England Journal of Medicine called “Effects of Intermittent Fasting on Health, Aging, and Disease.”
It summarizes the accumulating evidence suggesting that skipping meals (and snacks)—aka “intermittent fasting” (IF)—can have profound impacts on our health.
Researchers originally thought that the benefits of IF were mostly due to weight loss.
However, this is no longer the case. Evidence now indicates that intermittent fasting has several positive effects that are unrelated to weight, including:
Improving blood sugar regulation, heart rate, and blood pressure
Increasing stress resistance
Slowing the effects of aging
Reducing inflammation
Improving cognitive function
Why does IF have so many benefits?
Being in a fasted state activates cellular pathways that remove or repair damaged molecules and improve our defense against oxidative and metabolic stress.
There are several different approaches to IF, including alternate-day fasting (eating only every other day), 5:2 fasting (eating five days per week, and fasting two days), and time-restricted eating (typically eating only during a six- to eight-hour window each day).
All can be effective, but in my work with patients, I’ve found that time-restricted eating is the most practical and sustainable approach for most people.
This might mean eating only between noon and 8:00 p.m. each day (for an eight-hour window) or between 8:00 a.m. and 2:00 p.m. (for a six-hour window).
There’s some evidence that eating only in the morning or daytime is better than a later window, i.e., 2:00 p.m. to 8:00 p.m. However, this is challenging socially for people who want to eat dinner with family and friends, so most find it easier to include dinner in their eating window.
If you’d like to give time-restricted eating a shot, make sure to start slowly to give your metabolic machinery a chance to adapt.
For example, you could begin with a 10-hour food window five days per week for the first month, then go to an eight-hour window five days per week for the next month, then an eight-hour window seven days per week, then, finally, a six-hour window seven days per week.
Also, remember that there’s no one-size-fits-all approach when it comes to this stuff.
I’ve found that some of my patients don’t do well with prolonged time-restricted eating, especially with shorter (i.e., six-hour) windows every day.
I’m not sure why this is the case, but I suspect it’s because fasting, although beneficial, is a stressor. If someone already has a very high level of background stress, the additional stress of time-restricted eating may push them over the edge.
Another potential cause of difficulty might be for people who are already underweight or in a hypocaloric state due to chronic illness. In these cases, time-restricted eating may accelerate weight loss and further decrease calorie intake, which isn’t desirable.
As always, let your own experience and your body—rather than a theory—be your guide.
