Intermittent fasting is one of the most polarizing, hotly-debated wellness topics right now. Ask a group of friends at brunch what they think about intermittent fasting and the responses will range from “It changed my life” and “I could never. I’m not cute when I’m hangry” to “Yeah, dude, I’m fasting right now. That’s why I’m out here drinking water while you’re all guzzling bottomless mimosas.”
The hashtag #intermittentfasting has been used in over 4.5 million Instagram posts, and the book Fast This Way by the self-proclaimed “father of biohacking,” Dave Asprey, has an average of 4.5 stars from 2,300 reviewers on Amazon. Asprey, who shares tips about optimizing for health and wellness, has over 289,000 followers on Twitter who seek intermittent fasting and biohacking tips.
What’s the Hype All About?
Intermittent fasting is a diet that focuses on a strict schedule around eating and fasting. Besides promoting weight loss, the benefits include improved heart and brain health, decreased inflammation, lower risk of diabetes, balanced hormone levels and a longer life-span. Those who practice intermittent fasting report that they feel a surge of energy and alertness during fasting periods, which vary depending on which type of intermittent fasting you decide to try.
Here are three of the most popular intermittent fasting methods:
- The 16/8 method splits each day into two sections—a 16-hour fasting period in which you can’t eat food or calorie-containing beverages, and an eight-hour period in which you can eat what you want. Most people choose noon-8 p.m. as their eating window so that they only need to skip breakfast, while keeping lunch and dinner on the menu.
- The Eat-Stop-Eat method, invented by Brad Pilon, involves fasting for two whole days out of the week. Pilon emphasizes on his website, “You still eat every single day.” With this method, a 24-hour fasting period can be from 7 p.m. on a Tuesday to 7 p.m. on a Wednesday, for example. The rest of the days, you’re allowed to eat whatever you want as long as you “eat responsibly,” per Pilon’s instructions.
The 5:2 method involves restricting your calorie intake for two days of the week and eating normally for the remaining five days. On fasting days, this diet allows you to consume 500 calories per day for people assigned female at birth and 600 per day for people assigned male at birth.
Seems simple enough, right? As enticing as the potential benefits might be, intermittent fasting isn’t for everyone. According to Harvard Medical School, limited studies show that dropout rates for this regimen can reach up to 38 percent. While some people do gain a beneficial psychological effect from intermittent fasting, others might not find the process as rewarding.
Read more: The Surprising Ease of a Digital Detox
Intermittent Fasting Isn’t for Everybody
Skipping meals for huge chunks of time is not ideal for people with preexisting health conditions, like diabetes. “Anyone taking insulin injections to treat their diabetes, especially type 1 diabetes, may not be good candidates for intermittent fasting,” explains dietitian and diabetes care specialist Diana Gariglio-Clelland, RD, CDCES.
Intermittent fasting can increase insulin resistance, which is great for someone who’s trying to eat a healthier diet or lose weight, but very harmful for someone who’s injecting insulin. Symptoms of hypoglycemia, or low blood sugar, can worsen during intermittent fasting. These symptoms include nausea, sweating and fatigue—or worse, dizziness and fainting.
Gariglio-Clelland adds that pregnant people and people who have undergone weight loss surgery should check with their doctor before hopping on the intermittent fasting bandwagon.
Dietitian Ana Reisdorf, MS, RD, adds that intermittent fasting won’t work for people who are already stressed out. “Piling intermittent fasting on top of an already stressed body will only result in hormonal dysfunction, increased body fat and possibly impact[ed] sleep,” says Reisdorf. Cortisol levels can skyrocket, especially for women.
People with Eating Disorders Should Be Cautious about Intermittent Fasting
Like any diet, intermittent fasting has a learning curve. You’ll probably start day one a couple of times before truly getting the hang of it. You might throw in the towel altogether because you want to drink those bottomless mimosas with your friends at brunch. On the other hand, people who currently struggle with eating disorders, or have dealt with them in the past, should be extremely cautious about intermittent fasting.
Because of the prevalence of diet culture—flat tummy teas promising quick results, enticing before-and-after photos and unabashed fat-shaming online—it’s easy for disordered eating to masquerade as wellness. Here are a few symptoms of general eating disorders listed by The National Eating Disorders Association:
- Refusal to eat certain foods, including restricting whole food groups like carbohydrates
- Skipping meals or taking small portions of food at regular meals
- Discomfort while eating around other people
- Engaging in food rituals, e.g. not allowing foods to touch each other on the plate
- Extreme concern with body size and shape
If you struggle with some of these symptoms, but still want to reap the many benefits of intermittent fasting, don’t be afraid to seek extra support. When her clients want to try intermittent fasting, integrative nutritional health coach Brandi Muilenberg asks these three simple questions to figure out if the diet is a good fit for them:
What is your current relationship with food?
Have you had an eating disorder in the past? If so, swipe left on intermittent fasting as it can trigger and initiate eating disorders all over again.
Do you suffer from emotional eating?
Emotional eaters tie a feeling of reward to binge-eating and punishment to fasting. Muilenberg says, “When combined with intermittent fasting, emotional eating often creates binges followed by feelings of failure or lack of self-worth. Emotional eating must be addressed and healed before intermittent fasting can be added to someone’s routine.”
Finally, Do you know your hunger cues?
“This seems like a silly question,” says Muilenberg. “But we have forgotten how to listen to our bodies. Most of us go through the day and eat when the clock says it’s time, or only when we’re stressed.” Creating an awareness of hunger cues is crucial to staying sane while starting intermittent fasting.
Take What You Like and Leave the Rest
If you’re still on the fence about intermittent fasting, remember that you don’t have to try the entire diet to leave with some good lessons. Eating on a regular schedule can help you plan healthy meals ahead of time, saving room for brunch and dinner dates where you can splurge a little bit.
You might even find that you’re already fasting in your own way, not necessarily as described by the specific guidelines other people use. If you typically eat dinner at 7 p.m. in the evening, then don’t eat breakfast until 8 a.m. the next morning, you’ve already fasted for 13 hours. And you didn’t have to do anything special but follow your body’s natural rhythms.
You can take baby steps toward the 16/8 method by pushing your breakfast a half an hour later for one month. In the following month, push dinner half an hour earlier. Keep making small changes in your daily routine until you hit that 16/8 sweet spot. Sure, it may take months to reach a goal like this, but you’ll get there with steady faith that you’re doing what’s best for your body—and your mental health.
Header image by Rachel Gorjestani via Unsplash.
Read more: How Gut Health Affects Mental Health
Read more: Following Her Gut
Read more: What to Know About the Gut Microbiome