As a culture, we go through a ridiculous amount of diet phases. First, was low-fat, now it’s low-carb; don’t eat after 7 p.m., raw foods only, Whole 30… I could go on and on. One way of eating that I have been getting a lot of questions about lately is intermittent fasting.
What is intermittent fasting? Essentially, it is exactly what it says – fasting for intermittent times during the day or on certain days. There are several different fasting strategies; with the two most popular being severe restriction of calories 1-2 days per week or going 12-18 hours without eating; aka a "fasted window". Below are a couple sample schedules of these popular strategies:
The thought behind intermittent fasting is that eating all your food in a smaller window leads to eating less calories overall. Some research has shown that intermittent fasting may lead to weight loss. Of course; just like the beginning of any new diet; when you start to restrict calories, you will see weight loss. The problem is, the weight loss will slow because chronic restriction leads to a slowed metabolism and other medical consequences. And researchers also agree that more research is needed in the area of intermittent fasting for weight loss.
I’ve talked with several people who have tried intermittent fasting. The folks who are natural breakfast skippers thought it was no big deal; however, those that regularly ate six small meals a day said it was everything they could do to not ravenously scarf down their first meal at 2:00 p.m.
Personally, what I really want to know about intermittent fasting is:
Horne, B. D., Muhlestein, J. B., & Anderson, J. L. (2015). Health effects of intermittent fasting: hormesis or harm? A systematic review. The American journal of clinical nutrition, 102(2), 464-470.
Johnstone, A. (2015). Fasting for weight loss: an effective strategy or latest dieting trend?. International Journal of Obesity, 39(5), 727.
Klempel, M. C., Kroeger, C. M., Bhutani, S., Trepanowski, J. F., & Varady, K. A. (2012). Intermittent fasting combined with calorie restriction is effective for weight loss and cardio-protection in obese women. Nutrition journal, 11(1), 98.
Allison Tropf, MS, RD, CSSD
Allison is a Sports Dietitian in Michigan. She enjoys helping others reach their nutrition and fitness goals through reliable and trustworthy recommendations.
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