Intermittent Fasting, Disordered Eating Habits, and Causes for Concern
**TW: Talk of eating disorders, disordered eating, etc
This post focuses on intermittent fasting, pulling from expert opinions to discuss the good, bad, and consequences of restrictive dieting.
I understand these are sensitive topics for many people, so please put your well-being first before continuing to read.
Disclaimer:
I want to make it abundantly clear that as a certified personal trainer and certified nutrition coach, it is NOT within my scope of practice to diagnose or treat any illness, prescribe meal plans, conduct nutrition assessments, or make specific recommendations.
Though this newsletter relays information on fad diets, disordered eating, and similar topics, they are not my specific opinions and rely on facts presented by experts and research.
It is my opinion that fad diets are problematic, but this opinion is supported by facts and research and it is within my scope to state and explain this.
Registered Dietitians are licensed professionals and use their expertise to counsel on nutrition issues and healthy eating habits. RDs are essentially the only professionals you should go to for specific nutrition advice and assistance.
These facts are especially important to keep in mind as people turn to social media for information and education. Not everyone who shares health and nutrition information is qualified to do so. Be mindful of who and what you’re listening to.
Intermittent Fasting Explained
Though fasting has been around for centuries, it’s difficult to pin down when exactly intermittent fasting originated. What we know for sure is that this diet has gained popularity in recent years. But what exactly is intermittent fasting and what’s the point?
At its most basic form, intermittent fasting can be defined as “periods of fasting alternating with periods of eating.”
From there, the definition gets more difficult as there are a variety of methods differing in how many hours or days fasting lasts.
According to the Cleveland Clinic, these are some of the most popular fasting methods:
Time-restricted eating: Set fasting and eating windows, such as the common 16/8 method of fasting for 16 hours and eating for 8.
Twice-a-week method: Also known as the 5:2 method where you eat a normal and healthy diet for 5 days and restrict caloric intake to 500 calories for 2 days a week.
Alternate days fasting: Essentially one day of normal eating alternated with one day of limited calories, often around 500.
The 24-hour fast: where you completely fast for 24 hours, often once or twice a week.
Regardless of the method, there are a number of reasons people attempt intermittent fasting, such as weight loss. According to research (which will be discussed below,), there are many potential health benefits of intermittent fasting that could contribute to its appeal, including reduced blood pressure, lower cholesterol, and reduced inflammation.
Eating Disorder vs Disordered Eating
Though both terms will come up, it’s important to note that they aren’t the same thing.
Disordered Eating
According to the Academy of Nutrition and Dietetics, “Disordered eating is used to describe a range of irregular eating behaviors that may or may not warrant a diagnosis of a specific eating disorder.” These behaviors include:
Food Anxiety
Frequent weight fluctuations
Feeling out of control around food
Using exercise or food restriction to compensate for “bad” food decisions
These are just a few examples of the signs and symptoms of disordered eating. Many people with these symptoms often don’t realize how badly these behaviors are impacting them, physically and mentally, which can make symptoms worse.
Though having these symptoms doesn’t always result in the diagnosis of an eating disorder they are still a cause for concern and should be treated by a registered dietitian with experience in (or specializing in) the counseling of patients with eating disorders.
Eating Disorder
The Academy of Nutrition and Dietetics says, “The most significant difference between an eating disorder and disordered eating is whether or not a person's symptoms and experiences align with the criteria defined by the American Psychiatric Association. The term "disordered eating" is a descriptive phrase, not a diagnosis.”
Eating disorders, such as anorexia nervosa, require narrow and specific criteria to be diagnosed. Many people with disordered eating symptoms are diagnosed with Eating Disorder Not Otherwise Specified (EDNOS,) but this too requires narrowing criteria to diagnose.
Eating disorders have numerous negative health effects, often depending on what specific eating disorder is diagnosed. From nutritional deficiencies to more severe issues like kidney problems and heart issues, they should be taken seriously and are never appropriate methods for weight loss.
It’s also very important to note that, according to the Academy of Nutrition and Dietetics, the way a person looks might not show how they’re being physically or emotionally affected, nor how much harm they’re causing themselves.
The National Eating Disorders Collaboration discusses eating disorders in people with higher weights and how even today, with bountiful evidence showing that these disorders occur across a range of body types, those with higher weight might not be diagnosed by medical professionals due to weight stigma.
What Research Says About Intermittent Fasting: The Positive
Though I want to focus this post on the potential dangers of diets like intermittent fasting, it’s also important to note the possible benefits supported by research.
Many studies specifically discuss positive findings based on animal testing, a practice that doesn’t provide quite enough credibility.
When it comes to studies involving humans, there isn’t a ton of information available. Here’s what we know:
A small, relatively short-term study on the benefits of intermittent fasting on asthma found “rapid and sustained beneficial effects of ADCR [alternate day calorie restriction] on the underlying disease process in subjects with asthma.”
This article cites the potential short-term benefits of intermittent fasting as “weight loss…decrease[d] inflammation, as well as improve[d] blood sugar regulation…”
Some studies do question how many of the benefits of intermittent fasting are due specifically to the diet, and how many are simply due to calorie restriction.
What Research Says: Concerns for Disordered Eating
According to a Healthline article on IF, “[r]esearchers say that calorie restriction appears more successful than intermittent fasting for weight loss…Researchers write that this suggests that the size and frequency of meals — along with total calories eaten per day — have a bigger impact on weight change than the timing of meals.”
Similarly, according to Dr. Frank Hu, chair of the Department of Nutrition at the Harvard T.H. Chan School of Public Health, “There's no strong evidence that fasting adds health benefits beyond any other weight-loss strategy.”
Kathy McManus, director of the Department of Nutrition at Brigham and Women’s Hospital, describes the goal of nutrition counseling as “to develop a healthy eating pattern that is sustainable and can support weight loss over time.” Severe calorie restriction is not a healthy and sustainable way to learn how to eat long-term. Like a lot of other diets, intermittent fasting creates an unrealistic environment for individuals to succeed in the moment but doesn’t offer the tools to be successful in maintaining weight once someone stops. In addition, the article says “as of now, intermittent dieting has not been approved to meet this key criterion.”
The Meadow Glade, a rehabilitation facility specializing in eating disorders, posted an article on eating disorders getting rebranded, focusing on intermittent fasting as a form of extreme food intake restriction. This post also highlighted the concerns medical professionals have on the long-term effects of fasting, including an increased risk of diabetes and other health problems along with an increase in binging behavior on eating days.
It’s too broad to claim that intermittent fasting is bad for everyone, but serious thought needs to be put into recommending this diet.
This study on university students doing low-carb and intermittent fasting found an increase in disordered eating related to these behaviors.
Many of the concerns involving intermittent fasting are due to its restrictive nature and the negative effects these behaviors can have on individuals.
Why Restrictive Behaviors can be Detrimental
Though most diets rely on some form of restriction to promote weight loss, restriction itself can be a problematic behavior that might lead to a slippery slope from disordered eating behaviors to an eating disorder.
I wrote a post about restriction last fall and I suggest taking a read. This post discusses the problem with putting morals on foods, the restrict-binge cycle, and how dieting can lead to these harmful disordered eating behaviors.
RDN and LDN Nicole Goodrich's post summarizes the Restrict-Binge Cycle well: “Restriction in any form – under-eating or restrictive food rules – can lead to a natural drive to eat. Sometimes this drive to eat can result in a chaotic eating experience like a binge. And the restrict-binge cycle begins.”
Restriction doesn’t only have to come in the form of limiting the types of food you eat. Intermittent fasting requires the restriction of eating to certain periods of time.
Binging as Protection
Rachael Hartley, RD, LDN, also speaks of the physical effects of restriction in her article and how the Restrict-Binge Cycle is actually a form of protection. Starvation has been one of the greatest threats to our survival since the beginning of time. Our bodies are built to survive periods of time without enough food and have a system to fight restriction.
Hartley describes this system as such: “[o]ne of the ways your body protects you is by ramping up hunger hormones in response to restriction. Ghrelin, the main hunger hormone …stays elevated when you’re undernourished, even after a normal-sized meal. In fact, a year after weight loss, ghrelin levels are still elevated while leptin, the fullness hormone, is suppressed. Your body is trying to signal, via hormones, for you to eat more food.”
Most people don't consider the biological and psychological components meant to protect your body that can keep you in this restrict-binge cycle.
Intermittent fasting can easily lead to a cycle of restriction and binging regardless of intentions, but the likelihood of this slip into disordered eating patterns isn’t always taken into consideration when fasting diets are recommended and encouraged.
The Takeaway
Though many who choose intermittent fasting as a dieting method never suffer from disordered eating behaviors, it’s still fair to say that long-term, sustainable habits are likely not learned and the chance of weight regain is high.
The concerns of intermittent fasting leading to disordered eating behaviors, potentially escalating to an eating disorder, do not seem worth the potential benefits of this diet.
Intermittent fasting might not cause disordered eating patterns, but those already suffering from these behaviors might feel they are essentially being given permission to continue with their unsafe habits in the name of weight loss.
While the road to nourishing and sustainable nutrition takes a lot of work, introspection, and unlearning, living a life where you’re not obsessing over your weight or tracking calories is worth putting in the work.
If you’re concerned about your own habits or are interested in learning about creating sustainable nutrition habits, I recommend looking into a registered dietitian near you.
If you want to chat more about this article, look into other ways to employ sustainable habits, or work on improving your physical health, contact me or sign up for a consultation.
Photo by Callum Shaw on Unsplash