What is it? Intermittent fasting (IF) is a popular weight loss approach in which we refrain from food or drink for a specific amount of time, or limiting days of the week to fast. The idea of intermittent fasting comes from the Paleolithic period, during the hunter-and gatherer times when food was not always readily available. Variations of the diet have been around for ages but in the last 5-10 years it has been popularized primarily for its weight loss functions. Some believe it is a good way to not only lose weight but also reduce the risk for heart disease and diabetes. It is also said that fasting may improve cognitive function and increase muscle mass.
There are number of ways to practice intermittent fasting but the most popular are as follows:
– 24 hours: Eating 2-3 times per week normally followed by a full 24 hour fast in which the only items allowed is water, black coffee and tea.
– Calorie Restricted days: follow a normal healthy diet for 5 days of the week, 2 non-consecutive days of eating 300-600 calories per day.
– Time Restricted daily: abstain from food or drink for 16 hours and allow an 8 hour eating window. These windows are flexible and can be worked around that works best for each person.
There is some evidence that combining intermittent fasting with a healthy diet and lifestyle can be an effective approach to weight loss for those with no underlying conditions. IF may reduce or eliminate nighttime eating which can also promote weight loss. Many believe however that the diet works because participants are eating less than they normally would. A major part of effectively utilizing IF is to avoid refined grains, and sugar; instead eating fruits, vegetables, legumes, whole grains, and lean proteins. This idea following a healthful diet is the common recommendation from dietitians across the globe, regardless of the eating pattern.
Despite some evidence promoting intermittent fasting, many dietitians are skeptical on recommending the dietary pattern as a weight loss tool. It is not recommended for those who are pregnant, have diabetes or who has other health conditions, especially those on medications. Also, following a diet with restricted time frames can be difficult to follow. It could promote the “starve and binge” concept to weight loss which has been proven to be harmful. Hormonal imbalances have also been reported in women who follow IF.
If interested in intermittent fasting, please contact your dietitian and discuss options that could best suit you.
Written by: Michelle Switach – Dietetic Intern