Intermittent fasting is a trend that seems to have taken the wellness world by storm. Enthusiasts love to advertise on its behalf – its benefits are said to include weight loss, a regulated metabolism, and an increase in energy.

So is intermittent fasting the real deal, or is it just another trend that will fade out over time? We’ve enlisted the help of Erin Brudz, registered dietitian and Clinical Nutrition Manager at both campuses of Sisters of Charity Hospital, to determine if the science behind this eating plan checks out. 

What is Intermittent Fasting, Exactly?

Intermittent fasting is the practice of limiting your food intake in a way that cycles between defined periods of fasting and non-fasting. In contrast to many traditional diet mentalities, intermittent fasting focuses more so on when you’re eating as opposed to what you’re eating

“There’s potential that following a daily time-restricted fast, and eating mainly in the early hours of the day, will enhance our metabolism, both to coordinate with natural circadian rhythms and promote weight loss,” Erin says. Circadian rhythm refers to the human body’s internal clock, and the idea that eating nutritionally-dense food at certain times of the day can fuel our body to perform at its best.

“[Still] weight loss is the most common and sought-out benefit of intermittent fasting, usually through modification of body composition, while overall fat decreases,” Erin says. 

Here are a few more of Erin’s answered to the most frequently-asked questions about intermittent fasting.

Erin Brudz, RDN, CDN

Erin Brudz, RDN, CDN

Clinical Nutrition Manager, Sisters of Charity Hospital & St. Joseph Campus

What's the science behind intermittent fasting?

Fasting puts our body into a moderately-stressed state referred to as hormesis. In hormesis, our cells adapt, which may increase fat burning, our metabolic rate, and other internal processes. 

Most of the time, participants eat fewer overall calories than those who do not fast, therefore resulting in weight loss. This could be due to a number of behavioral factors, or simply that a restrictive window of time for eating discourages certain habits, like late-night snacking. 

Can you lose weight eating the same amount, but adjusting when you eat?

More research would need to be conducted to compare fat mass changes between a person who eats the same amount of calories, once while intermittent fasting and once while eating normally. 

We have to keep in mind that there are limited human studies that prove intermittent fasting in directly responsible for all these associated benefits and outcomes. The studies that have been done are short-term, and long-term effects are not yet known. 

Is intermittent fasting safe for everyone to try?

Intermittent fasting is not recommended for women who are pregnant or lactating, for children/teenagers, the elderly, underweight individuals, or those who have a history of disordered eating. Some people who are on a medication regime may feel better eating the standard 3 meals a day. 

In addition, intermittent fasting has been shown to cause hunger pains and general irritability in its participants. Some people may find this disruptive enough that it will start to affect their lifestyle… or experience a sense of isolation as a result of not being able to enjoy social events that involve meals during fasts. 

What about the idea that "breakfast is the most important meal"?

It’s common for participants to skip what we understand as “breakfast” to meet the time limits of their fast. However, the term “breakfast” actually refers to whatever time we first break the overnight fast, or the meal that provides our bodies with glucose and other nutrients to fuel our metabolism. 

We have come to equate breakfast with a meal that needs to be eaten early in the morning, though that’s not necessarily the case. Regardless of when we eat, the quality of food consumed is too significant to our overall well-being to be overlooked. 

As a dietitian, what concerns you about intermittent fasting?

The biggest concern I have is that no matter what kind of dietary restriction a person has self-imposed, the food being eaten needs to be well-balanced, giving individuals enough nutrients to maintain adequate energy levels during the day. No individual, intermittent fasting or not, should put themselves at risk for nutrient deficiencies. 

Is one method of intermittent fasting more effective than another?

Some people will restrict their eating to an 8-hour window, while others alternate between a full day of fasting, and a day of eating normally. There is not one method of intermittent fasting that is currently proven to be more effective than another on the whole. 

Just as with normal eating habits, fasting should be done based on the individual and their lifestyle. Some people can tolerate true fasting during waking hours, while others perform better eating more frequently. 

Find a Registered Dietitian Near You
Call (716) 706-2112

Find a Registered Dietitian Near You
Call (716) 706-2112