Intermittent fasting is abstaining from eating or drinking for a period of time.

It’s better described as an eating pattern than a diet.  It limits when to eat (in terms of certain hours per day or days per week) and not so much what to eat.  And that’s part of its appeal to people who don’t want to count calories or use their food log to track everything.

Some say that it’s a more natural way to eat because humans evolved without refrigerators, drive-through restaurants or 24-hour convenience stores.  We now have access to food (including junk food) all day long, so eating several meals per day plus snacks may be less natural than fasting from time to time.

There are lots of variations on this theme.  Here are two examples:

• 16/8 which is 16 hours of fasting, and eating only within the other 8 hours (often 1:00 p.m. to 9:00 p.m.).
• 5:2 days of fasting, where you eat regularly for five days of the week, then take in just 500-600 calories/day for the other two (non-consecutive) days.

One question that comes up that we’ll address here is how effective is intermittent fasting with regard to weight loss?

Intermittent fasting can help you to lose weight because it can help you to eat fewer calories and burn more calories, too.

Lots of people say they have success with it.  But what do the studies say?

According to one review study, intermittent fasting helped people lose three percent to eight percent of their weight over a period of 3 to 24 weeks.  In this study, people also lost four percent to seven percent of their waist circumference (belly fat).

Another study of 100 people with obesity showed that after a year, the people who fasted on alternate days lost more weight than people who didn’t change their eating pattern.  But, (and here’s where it’s interesting) they didn’t lose any more weight than those on a calorie-restricted diet.  Out of the people who were to follow the intermittent fasting protocol, 38 percent of them dropped out.

Sticking with a diet is one of the keys to weight loss success.  So, if you can’t stay with a weight-loss diet, you’re less likely to lose the weight and keep it off.

Intermittent fasting is not for everyone.  People who are underweight or who have eating disorders shouldn’t fast.  Also, women who are pregnant, trying to get pregnant or who are breastfeeding shouldn’t fast.

Certain medical conditions can be worsened with longer periods of fasting.  And people taking certain medications can be prone to side effects with intermittent fasting as well.

One of the reasons people drop out of the intermittent fasting eating pattern is that it’s hard to stick with the fasting part.  They eat more than the allowed (low-level of) calories when they’re supposed to be fasting.  And when they finish fasting, they may overindulge due to the reaction of the appetite hormones and hunger drive while fasting. None of these situations will help with weight loss.

The hours and days of fasting can be very difficult.  So having strong social support will be key during those intermittent periods of fasting.  Sticking to a (healthy, nutrient-dense) weight loss diet is the key to success, and intermittent fasting can be difficult for many people to stick with.

So to sum up, we can say intermittent fasting is a weight loss trend that seems to work for some people.  It may help one to lose weight and reduce belly fat.  But, it isn’t safe for everyone.  In fact, it may be risky for many people.  More research and studies are needed.

If you’re planning to diet, it’s key to find a diet or eating pattern you can stick with for your best chance of achieving long-term weight loss success.

What about you?  Is intermittent fasting something you might consider?  Have you or has someone you know tried intermittent fasting?  What were the results?  Please let us know in the comments below.  As always, we love to hear from you.