The skinny on fasting: Taking long breaks from eating has many benefits

by Laura Straub 

While “intermittent fasting” – which restricts eating periods to certain days or times – is among one of today’s trendiest diet and wellness strategies, it’s “not quite as new as it would seem,” said Dr. Christine Alexander-Rager, chair of the department of family medicine at the MetroHealth system and associate professor of family medicine at Case Western Reserve University.

“In some ways it is a rephrasing of good advice we’ve given for years, like not eating heavy before bed and limiting snacking after dinner,” Alexander-Rager said.  

The concept of intermittent fasting might even have roots deep in human history. 

“Evolution has taken us from a society focused on hunting and foraging for food, which likely led to eating one large meal once daily, to a society focused on several, often large, meals per day,” she said. 

For those interested in giving intermittent fasting a try, there are a few different techniques.

According to Carolyn Bouquot, nutrition therapist and consultant, most of her clients can easily adapt to a time-restricted feeding method. She recommends they start by fasting for 12 hours and eat in a 12-hour window, or fast for 14 hours and eat in a 10-hour window. 

“For the daily fast, the most successful schedule has been eight hours of eating with nothing further to eat after about 3 p.m.,” added Alexander-Rager. 

Fasting mimicking diets have also been a popular regimen with Bouquot’s clients. For five days out of the month, the individual will restrict themselves to 800 to 1,100 calories per day. They must maintain this pattern for a minimum of three months. 

So far, studies have shown that both techniques deliver similar results. 

“The way this works is that you have to avoid all intake during periods of fasting. This is what drives down our insulin levels to allow the burning of stored calories,” said Alexander-Rager. “You will feel very hungry during these times, and it can be hard to not snack at all.” 

However, keeping the benefits in mind can help maintain willpower. 

Although data in humans is still emerging, intermittent fasting has been tied to improvements in metabolism, blood sugar, cholesterol, blood pressure, body fat and inflammation. 

“Overall, several conditions can be improved including preventing pre-diabetes from turning into diabetes, improving diabetes itself [and] improving heart rate, blood pressure and cholesterol, which could lead to less heart disease and decrease risk of [neurological] disorders like Alzheimer’s, Parkinson’s and strokes,” Alexander-Rager said. 

Ultimately, the doctor said, sticking to an intermittent fasting regimen comes down to behavioral change. 

“It is really hard to change behaviors, whether that is our eating habits, smoking or alcohol use,” she said. “Food habits are deeply ingrained in our society and three square meals per day is the norm. Our work and school days are planned around it and typically our evening meal is our heaviest. It is linked to family time and many studies have shown benefits for children who are raised in houses where they have dinner together nightly.” 

To make it work, create new norms.

“First decide which method of intermittent fasting to attempt – alternate days or fasting within the same day,” she said. “Know yourself well enough; are you better with a slow start or cold turkey type approach? Let your approach to making this change reflect that; it tees you up for success.” 

After that, pick a clear start date during a low stress time, as fasting will also stress the body. Tell your friends, family and co-workers and ask for their support. Start eliminating snacks between meals and after dinner. Avoid strenuous exercise while fasting, as well as exposure to extreme hot or cold temperatures. Be prepared for side effects during fasting, such as weakness, headache, caffeine withdrawal and dry mouth. 

Although you might not succeed at your first attempt, stick with it. It’s common for people to fail several times before making a permanent behavioral change. 

“Be prepared for those cheat times with high nutrition snacks like cut vegetables, fruits and whole grains,” Alexander-Rager said. “It is really easy to slip back into high calorie, low nutrition and refined carbs. [Try instead] vegetables like broccoli and cauliflower which are more filling and can help to bridge the gap until the next meal is due.” 

Enlisting the support of a nutritionist or health coach can help as well. 

Although intermittent fasting is a promising nutrition trend, Alexander-Rager acknowledges that the long-term effects are still largely unknown. With that in mind, she notes that staying active and eating a diet of whole grains, lean proteins, vegetables and fruits will always serve a body well.