Intermittent Fasting

Too Close To Home For Those In Eating Disorder Recovery

This week alone 3 different clients came into my office asking about intermittent fasting. I wondered why and then embarked upon writing this important blog regarding the dangers of intermittent fasting (IF) as it relates to those in recovery for eating issues. We at Integrated Eating join other non-diet dietitians in encouraging whole health and against dieting behaviors. 

The Myth

This trendy new diet is just that. A diet. All diets have the same MO-weight loss through restriction (calories consumed must be less than calories expended).  Proponents of this new fasting craze tout it provides quick weight loss, reduces inflammation and other risks related to heart disease. 

What is Intermittent Fasting?

The specific flavor of diet that IF proclaims involves alternating intervals of EXTREME caloric restriction with periods of normal  eating or “feast” days. Severely limiting calories on certain days or during specific hours of the day and then resuming normal eating or “splurge” eating on others. But wait, get this! The philosophy surrounding this dangerous envogue diet is that intermittent fasting will decrease appetite by SLOWING down the body’s metabolic processes¹.

Research

One of the most important things to consider with any fad diet is that while the diet is piquing in mainstream society there is usually no real evidence that warns of its prolonged effects. 

As of current, there has not been a lot of research on IF. Of those few studies that are taking place they have small sample sizes limiting the efficacy of what these studies find. Interestingly enough, those few studies done on IF have a very high (almost 40%) dropout rate...giving us a message about the difficulty to sustain a diet of this ilk².

Some of the draw with IF comes from research done with animals suggesting fasting may reduce cancer risk and slow the aging process. ³

Many of those conducting this kind of research though say there is no strong evidence that fasting aids in health benefits.

The LONG list of Cons...

Before getting into the specifics about why IF is a terrible idea for anyone with disordered eating or in recovery from an eating disorder, let’s discuss why it is a bad idea for just about anyone!

1) Your metabolism slows down. Our main goal as clinical dietitians is to help our clients move towards holistic health. One way to achieve this is to promote metabolic eating. Any style of eating that slows the rate at which body uses vital energy is not in line with health and wellbeing. A lowered metabolism triggers the body to store calories as fat and can lead to fatigue. 

2) Fasting promotes overeating- All diets, especially IF requires calorie restricting. Cutting calories by fasting for periods of the day can disrupt blood sugar balance leading the body to experience intense hunger, cravings, urges to overeat and binge eating. 

3) It can be dangerous for those with pre-existing health issues. Those with diabetes, heart or blood pressure issues are told to steer clear from embarking on IF because it can exacerbate these conditions. 

4) Nutrient deficits- Inherent to IF is decreasing food intake for certain periods of time. This can lead to macro and micro nutrient deficiencies including protein stores, vitamin B, iron and calcium to name a few.

5) It can cause sleep and mood disruptions- In addition to the rest of the list of possible issues resulting from intermittent fasting, mood and sleep can be disrupted. Without glucose the brain cannot function well. When individuals fast our stress hormones increase. This can lead to sleep problems, irritability, fatigue, weakness, anxiety and depression. 

So far this list tells us that instead of moving towards health IF encourages quite the opposite. But that unfortunately is not the end of the story. IF can promote disordered eating, eating disorder symptoms or full blown diagnostic eating disorders. Even for those folks without a history of dysfunctional eating, extreme restriction and subsequent compensatory eating can pull someone into the throes of an eating disorder. In one review study published in the journal Pediatrics, "extreme" dieting, including severe restriction of caloric intake (AKA, intermittent fasting), was predictive of eating disorders.⁴

For those who are recovery from an eating disorder please heed this-DON’T engage in this type of diet! 

The Bottom Line: 

If you look above at the contra indications and then overlay the crucial aspects of eating disorder recovery, you will see very clearly the two do no mingle. As specialists in the field of eating disorder nutrition, regardless of symptoms or category of ED, we: 

  • Seek to restore metabolic balance from underfed and undernourished bodies. 

  • Don’t approve of any eating style that promotes similar symptoms to the majority of eating disorders (restriction and compensatory eating) 

  • Don’t encourage any food plan that begs the body to enage in intense hunger, cravings or spurs food fears. 

  • Do not agree with any diet that inherently leads to nutrient deficiencies. 

  • Are not aligned with behaviors that whack the bodies natural body processes such as sleep or mood for our recovering folks. 

Before embarking on ANY type of diet fad, Integrated Eating strongly encourages discusses the dangers with a registered dietitian who has training in eating disorders. 

Notes: 

  1. Müller MJ1, Enderle J2, Pourhassan M2, Braun W2, Eggeling B2, Lagerpusch M2, Glüer CC3, Kehayias JJ4, Kiosz D2, Bosy-Westphal A5. Am J Clin Nutr. 2015 Oct;102(4):807-19. doi: 10.3945/ajcn.115.109173. Epub 2015 Sep 23. Metabolic adaptation to caloric restriction and subsequent refeeding: the Minnesota Starvation Experiment revisited.

  2. Trepanowski JF, Kroeger CM, Barnosky A, et al. Effect of Alternate-Day Fasting on Weight Loss, Weight Maintenance, and Cardioprotection Among Metabolically Healthy Obese Adults: A Randomized Clinical Trial. JAMA Intern Med. 2017;177(7):930–938. 

  3. Mattson MP, Longo VD, Harvie M. Impact of intermittent fasting on health and disease processes. Ageing Res Rev. 2017;39:46–58. doi:10.1016/j.arr.2016.10.005

  4. Neville H. Golden, Marcie Schneider, Christine Wood, Preventing Obesity and Eating Disorders in Adolescents, COMMITTEE ON NUTRITION, COMMITTEE ON ADOLESCENCE and SECTION ON OBESITY, Pediatrics September 2016, 138 (3) e20161649

Resources: 

https://www.health.harvard.edu/heart-health/not-so-fast-pros-and-cons-of-the-newest-diet-trend

https://www.healthline.com/nutrition/intermittent-fasting-metabolism

https://health.usnews.com/health-news/blogs/eat-run/articles/is-intermittent-fasting-an-eating-disorder

https://www.abc.net.au/triplej/programs/hack/wheres-the-line-between-fasting-and-eating-disorders/11258758