Eating Disorders Healthy Eating Mental Health

Intermittent fasting: Miracle diet or slippery slope to disordered eating?

Intermittent Fasting

Jack Dorsey, co-founder and CEO of Twitter, recently made headlines when CNBC published a story detailing his ultra-strict “health and wellness” regime that includes eating just 1 meal a day and fasting over the weekend. Dorsey credits his 5-meal-a-week diet for improved sleep and productivity, claiming:

“During the day, I feel so much more focused. … You have this very focused point of mind in terms of this drive,” Dorsey says. And ”[c]ertainly, the time back from breakfast and lunch allowed me to focus more on what my day is,” he says.

Jack Dorsey (photo credit: CNBC)

This is probably not the first you’ve heard of intermittent fasting. While Dorsey’s rather extreme diet seems to be driven by a desire for increased productivity, a form of intermittent fasting known as time-restricted eating is currently making waves for its potential for dramatic weight loss. By consuming all of a day’s calories in a limited window – for example, an 8 hour period between noon and 8pm – proponents claim to ingest less calories overall.

But does it work?

Ali Eberhardt and Hannah Robinson, registered dietitians with the Eating Disorders Program at St. Paul’s Hospital and co-hosts of a new podcast called “Let Us Eat Cake”, aren’t convinced that intermittent fasting is really all it’s cracked up to be.

“Intermittent fasting or ketogenic diets, like many of the fad diets, appear to demonstrate some short term impact to weight but the sustainability has not been studied as most people cannot continuously stay on the diet,” says Ali. “The problem with any of these diets is that they are very challenging to stick with. Whether you are cutting out major food groups or limiting hours of the day when you can feed your body, the likelihood of being able to continue these patterns long term is low, which can result in feeling like you have failed.”

And that feeling of failure is what drives people to dive into the next fad diet, hoping for different results.

“The diet industry is a multi-billion dollar industry because it sells people on unsustainable ideas,” says Ali. “The nature of a diet is to set rigid rules that are nearly impossible to keep long term. So someone might potentially see some initial results, then eventually they eat something they want or that their body desperately needs to survive – such as carbohydrates – and they break the diet, feel terrible, then find a new diet that allows the foods the last one didn’t, but cuts out a whole new set of foods.”

How will you know if a diet is sustainable?

If a diet is only possible to follow when you are home and able to do the prepping, chopping and calorie counting, but is not possible to follow on your birthday or at a work event or a dinner party or on vacation, then it likely won’t be possible to maintain it long enough to have sustainable results.

“This has nothing to do with willpower, resolve or commitment,” says Hannah. “Our body is a miraculous machine that is built to survive – and hopefully thrive – and will over-ride any diet intentions to get the fuel it needs.”

It’s not just the high risk of failure that has dietitians concerned about restrictive diets – there is real concern about the pendulum swinging the other way, causing a form of disordered eating known as orthorexia.

“Orthorexia is categorized by a fixation on a perception of health, and how food choices, or categories of food, can impact our health either negatively or positively,” says Hannah. “For example, it may start with someone hearing a media report about the negative impact of sugar, leading them to reduce their intake of added sugar. Thoughts about this diet can become more obsessive and fears develop of negative consequences that will occur if they have even small amounts of that food. The fears often amplify and the rules associated with “healthy eating” become more and more rigid, with fewer acceptable food choices.”

Orthorexia differs from more well-known eating disorders such as anorexia nervosa, which is characterized by an extreme fear of weight gain, obsessions with calories or fat contents of food, and a fixation on food topics.

“Both disorders do not allow for trust of the body,” says Hannah. “Instead, they cause a focus on rigid rules around food, impact of food on the body either with respect to perceived health consequences or changes to weight and shape.”

While orthorexia may not be intended as a way of changing weight it can present itself in similarly growing rules around food and what to eat. Eating disorders and disordered eating impact all genders, people of all socioeconomic status, cultures, sexual orientations, ethnicities and people of all shapes and sizes.

If you are concerned about your thoughts or actions around food, please seek support. Early intervention is a strong predictor for people healing their relationship with food and their bodies. The first step is to talk to a trusted health care provider to find out what resources are available.

Let us Eat Cake!

Want to hear more from Ali and Hannah? Tune into their new podcast Let Us Eat Cake, as they tackle diet culture, weight stigma, fatphobia and society’s obsession with “health and wellness”. Each episode is dedicated to using science and evidence-based nutrition to answer listeners’ questions and explain how our bodies actually work.

Listen on your Apple device, Android or smartphone using your podcast app (Apple Podcast App, Spotify, Google Play Music, SoundCloud) and search “Let Us Eat Cake”.  Please subscribe, rate and review!

Be sure to follow them on Instagram and Facebook, too.


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