Q: Many people I know are using “intermittent fasting” to lose weight. Is it effective? Are there health benefits? Should I try it?
A: Thank you for your questions as always. I actually have a few family members who follow an intermittent fasting “diet”, so I was very interested to research some more about this.
Intermittent fasting is followed in various forms by different people. The basics are that you limit your eating to a set number of hours per day. Most people it seems go with an 8-10 hour period, but I’ve heard of some restrict it down to only 2 hours per day.
What results are we seeing in scientific studies? Studies have shown that people have as good weight loss as just restricting their overall intake without a time restriction. But studies also indicate there may be benefits in relation to blood glucose and fat levels, which is good news for those at risk of diabetes and heart disease.
Why? This article from Harvard Health goes in much greater detail if you are interested. But in short, when we eat carbohydrates, one of two things can happen. First, those carbs are used for energy, which requires insulin (insulin levels are high). Second, they can be stored as fat. In between meals, when the body needs carbs but there aren’t any available (insulin is LOW), the body breaks down the fat for energy. This is good. We want the body to do this. But if we are CONSTANTLY eating, insulin levels stay high and we never break down that fat. Also, constantly overload of insulin can lead to our body not responding well to insulin, which can lead to diabetes.
But isn’t fasting hard? For some people, it can be. The Harvard article mentions some research that shows putting your eating period earlier in the day makes it easier rather than later (so 7 am-3 pm vs 12 pm – 8 pm). I think the timing of your fasting period is likely to be very individualized based on your preference and schedule. If you already aren’t a morning eater, don’t start just because of fasting.
Don’t want to fast? Me either. But there are some good take aways for EVERYONE, even if you aren’t intermittent fasting.
-Stop eating ALL the time. Allow insulin levels drop and you can burn some fat.
-“Hunger” in and of itself isn’t a horrible thing. Letting it get out of control so you eat out of control can be bad, but a little bit of hunger between meals is ok.
-Don’t eat late at night. This is likely to be just junk foods and shortens the periods of low insulin levels at night.
-Find what works for you. Fasters need to find the 8 hours that work best for them. Find what “schedule” of eating works best for you, be it 1, 2, or 3 meals a day. There is not a generic diet that will be perfect for everyone. You have to make it work for you!
Hope that helps!
Send questions to kimberlykmarsh(at)gmail(dot)com.
I’ve done some research on it lately, too, and tried it for a week to help rebalance some gut bacteria issues and it helped as much as many other things I tried. That’s just an n=1, but some really interesting research out there. It also seems like more infrequent 24-hour fasts may have similar benefits and effects on the gut microbiome. More research needed, but kind of fascinating! Great post!