Intermittent Fasting

If you are on social media or read digital news, you have probably heard of intermittent fasting. Intermittent fasting is a method of energy restriction for a fixed amount of time. Simply put, you do not eat for a period each day or week. IT does not specify what types of foods to eat, only when to eat them. While this may sound strange, some recent studies support the use of intermittent energy restriction (IER) for achieving and sustaining weight loss. With the growing rates of obesity and burden of chronic disease, it is no wonder that traditional weight loss methods are being challenged. Let us explore intermittent fasting and if it might help you.

Intermittent Fasting, Alternate Day Fasting, or Time Restricted Feeding?

Intermittent Fasting is the term used to describe weight loss strategies that involve limiting energy intake to certain periods of the day or extending the fasting gap between meals.

Alternate Day Fasting is eating a normal caloric amount one day and the next day eating either no calories or a meal that is less than 500 calories. Another method is the 5:2 fasting. Individuals eat normally for 5 days of the week and fast for 2 days.

Time Restricted Feeding is limiting the daily period of food intake to 8-10 hours per day or less on most days of the week. This is the most popular method of IER.

Is Fasting for You?

Several studies suggest that some method of IER has proven dynamic shifts in overall health. The changes include an increase in human growth hormone, which can help increase muscle mass and decrease fat. Studies also show a connection between fasting and increased insulin sensitivity, major changes to microorganisms that live in the gut that may help prevent obesity, improved repair of cells, and changes in gene expression that promote long life. While there might be a lot of “talk” about intermittent fasting, there has been a lot of recent investigation into it as well.

As far as IER and weight loss, it can be a challenging area to study due to the difficulty of controlling energy intake in humans. This is why we see a lot of studies coming from animals. Considering what the research shows, it is possible that IER can be a powerful tool for short term weight loss. However, more human studies with larger numbers are needed to draw more confident conclusions.

Careful Considerations for IER

Like any other restrictive form of eating, IER comes with side effects. Reduced caloric intake can cause symptoms such as hunger, temperature changes, fatigue, headache, low energy, and irritability. Continuous fluctuations between fasting and eating can also lead to gastrointestinal discomfort. More importantly, there are some populations that should not attempt an IER diet. Skipping meals may not be the best way to manage your weight if you are pregnant or breast-feeding. If you have kidney stones, gastroesophageal reflux, diabetes, or other medical problems, talk with your doctor before starting intermittent fasting.

Before adopting any major lifestyle change including IER, talk to your primary care physician or a registered dietitian.