Not so fast: Intermittent fasting isn't appetizing for everyone
Key Takeaways:
- Intermittent fasting is an eating plan that goes from fasting to eat on a set schedule.
- This diet plan helps with weight loss and calorie reduction. But it can cause overeating, fatigue, brain fog and more.
- Intermittent fasting isn't for everyone. Talk to your medical provider before starting a program.
Intermittent fasting has been around for a long time. But the eating plan that switches between fasting [not eating'] and eating on a set schedule, really took off in the early 2000s thanks to books, articles and documentaries highlighting the diet. By 2018, intermittent fasting got a boost due to celebrities like Jennifer Aniston and Hugh Jackman sharing success stories.
“They've heard people do well with it. They've seen some celebrity or a social media person say it's the thing that's helped them. Maybe it could,” says Nicole O’Neill, a registered dietitian with OSF HealthCare.
While many people have found intermittent fasting works, it’s not for everyone. O’Neill has consulted many people in the past 11 years who’ve tried using an eating schedule.
“In my years as a dietitian, I’ve had two patients use intermittent fasting successfully [losing weight],” she says. “Everybody else, it's a variation or a no-go. It just really depends on the person. That’s why it's important to work with a dietitian to determine if it will work for you or not.”
O’Neill adds that the emergence of weight loss drugs like GLP-1 medications have replaced the intermittent fasting diet for some.
There are many types of intermittent fasting methods, including the following:
16:8 – fasting for 16 hours and eating during an eight-hour window (for example, noon to 8 p.m.)
14:10 – a more normal approach with a 14-hour fast and a 10-hour eating window
5:2 – eating normally five days per week and consuming a significantly reduced calorie intake on two non-consecutive days
Before starting an intermittent fasting plan, O’Neill says it’s important to understand the benefits and drawbacks. “If intermittent fasting works for you, it’s an easy way to restrict your calories,” she says. “You're only going to eat twice during the day. And then you have that calorie deficit. And then you have weight loss.”
The cons of going long periods of time without eating include an increase in anxiety, fatigue, daytime sleepiness and even brain fog – not finishing words, thoughts or even tasks. Other potential issues are not getting enough protein, fiber, vitamins and minerals.
Not for everyone
O’Neill recommends eating two to three hours after waking up to help maintain energy levels and establish a consistent eating pattern.
“For some people, skipping breakfast is not going to work,” she says. “If they try to do intermittent fasting and wait until noon, they become so overly hungry that by the time they do get to their eight-hour eating window, they are out of control. They've eaten more calories than they would have if they would have had breakfast, lunch and dinner.”
O’Neill says if you have Type 1 diabetes, are pregnant, breastfeeding or under the age of 18, intermittent fasting is not recommended.
The bottom line, O’Neill says, is it won’t hurt to try intermittent fasting with guidance from a medical provider. It might just take some time to find the right method that works for you. A lot of it depends on your personality, lifestyle and other obligations.
“Any diet is worth trying because there are so many out there and we’re just individuals who need something specific for ourselves,” she says.