TLDR: Intermittent Fasting and Mental Health - Proceed with Caution

This article examines the complex relationship between intermittent fasting (IF) and mental health. Key points include:

1. IF's potential benefits for physical health and longevity

2. Risks associated with IF, especially for mental health and eating behaviors

3. The importance of individual factors in determining IF's suitability

Key takeaways:

• IF may have short-term benefits for weight management and cardiometabolic health

• However, it can lead to binge eating and eating disorder behaviors in some individuals

• The psychological profile and motivation behind IF are crucial factors

• IF driven by body dissatisfaction often leads to negative outcomes

Wise Mind Nutrition's stance:

• Generally does not recommend IF, especially for those with mental health concerns

• Emphasizes the importance of a balanced, consistent approach to eating

• Encourages focusing on overall well-being rather than just weight loss

The article concludes that while IF may benefit some, it poses significant risks for many, particularly those susceptible to eating disorders or with existing mental health conditions.

[Read full article for in-depth scientific explanations and references on IF's impacts]

Intermittent Fasting and Mental Health

Fasting has been practiced since the dawn of humankind when it was imposed by limited access to food. Our ancestors fasted, but usually not by choice. There is great interest in accessing ancestral wisdom concerning health behaviors. We are all for ancient practices. But is fasting right for everyone? Let’s look at the data and then discuss what we commonly see in clinical practice.

Intermittent Fasting Background

Intermittent fasting is all the rage nowadays. It appears to be one of the latest growing trends in fitness circles for altering body composition and losing weight. Intermittent fasting is commonly defined as the total abstinence of energy-containing food and beverages for 12-36 hours. Some people love it, and other people tend to fall apart when they give it a try. Some have even observed that intermittent fasting is one of the many causes of eating disorders.

Scientific interest in IF grew as part of investigations into aging and lifespan and was deemed part of The Longevity Diet by Professor Longo from the University of Southern California School of Gerontology. Importantly, these diet interventions also focus on non-refined carbohydrates, sufficient protein largely from plant-based sources, and most plant-based fats. Fasting by itself is not responsible for the longevity benefits but is part of a lifestyle overhaul.

According to Longo: “the longevity diet is not a dietary restriction intended to only cause weight loss, but a lifestyle focused on slowing aging, which complements standard healthcare and taken as a preventative measure, will aid in avoiding morbidity and sustaining health into advanced age.” There is a difference between eating for longevity and dieting for weight loss.

Then IF became popular in weight loss research and in fitness circles. Here comes “diet culture” which can be defined as the pervasive assumption that appearance and body shape are more important than physical, psychological, and general well-being. It makes sense that not eating would cause weight loss, right? Let’s take a deeper dive and then put it into the context of eating behavior and mental health.

Intermittent Fasting and Health Outcomes

Several trials have demonstrated that IF can cause weight loss in study duration periods from 8 weeks to one year [1]. Among individuals with higher weights, IF shows short-term benefits for cardiometabolic outcomes such as low-density lipoprotein cholesterol, total cholesterol, triglycerides, fasting plasma glucose, fasting insulin, insulin resistance, and blood pressure [2]. 

These conclusions have led to widespread press coverage of IF as a beneficial diet intervention for medical-related goals. But what happens over the long term? And what about mental health and our long-term relationship with food?

It has been suggested that some forms of time-restricted feeding may benefit mental health by improving brain signaling, neurogenesis, and synaptic plasticity [3]. These outcomes can occur when overall calories and overall nutrients are not reduced. In other words, strategies of “chrononutrition” are used to improve circadian rhythms by altering sleeping and eating patterns. For example, it’s been discovered that the gut microbiota, that is, the microorganisms that live inside us, are circadian coordinators of metabolism, immunity, and mood [4–6]. This is a very different conversation than diet culture’s common focus on weight loss and fitness.

Furthermore, most studies showing the benefits of intermittent fasting on outcomes such as brain health and longevity are in animal models, which lack the context of contemporary society. There are so many other factors to consider in everyday life that often get ignored in reductionistic biomedical models of nutrition. We believe in context!

Intermittent Fasting and Eating Behaviors

In the original sugar addiction research, rodents fed intermittently (e.g., fasted) displayed the worst symptoms of sugar bingeing [7]. In more recent rodent research, more restricted access to food promoted weight gain via binge-like intake and fat accumulation [8]. In a recent study of humans, fasting for approximately 16 hours per day for weight loss purposes was associated with heightened levels of eating disorder behaviors [9]. In our opinion, this is the worst possible outcome. It’s well established now that dieting and weight cycling cause metabolic damage and weight gain over the long term.

In both animals and humans, fasting can lead to binge eating. In humans, fasting can lead to an obsession with food, which can lead to impairments in social functioning as well as emotional distress. In fact, an IF plan can look identical to binge eating disorder (BED). One person might be engaging in time-restricted feeding without any binge eating, and the next can be restricted their food all day, bingeing at night, and calling it “IF.” The difference between these two individuals likely has to do with their psychological profile, level of body satisfaction, and the role of dietary restraint. Objectively, IF and BED can look identical.

Dietary restraint can be defined as the cognitive effort to restrict food intake for various reasons, but most commonly for weight loss [10]. Thus, it is critical to discern between IF which is used to stabilize circadian rhythms versus IF driven by dietary restraint, often generated from body dissatisfaction. 

Among women in midlife, greater levels of body dissatisfaction were associated with greater levels of dietary restraint, which in turn predicted greater psychological distress [11]. If fasting is used as just another “diet” the story usually doesn’t end well.

In our clinical practice, we see adverse outcomes associated with IF often. Most frequently, IF leads to loss-of-control eating and disruptions in social activities involving eating. In the short-term, many successful fasters report feeling better because they get the illusion of control over their appetite. But in the long-term, the hunger can rebound and be ravenous, leading to feelings of failure and disappointment. Most notably, people who fast for the wrong reasons often end up experiencing food with more intensity, which can feel like a “food addiction” when it is often times just a relic of deprivation [12].

 Learn more about why meal timing matters.

Conclusions

Wise Mind Nutrition generally does not recommend IF, however, we’re always open to helping you find a path that works best for you. If the interest in fasting comes from body dissatisfaction and is geared toward weight loss, it is likely to compromise your relationship with food over the long run and is highly discouraged. If you have benefitted from being more strategic with "when" to eat, and it hasn’t caused problems, honor that!

Fasting may have some benefits for people who are not susceptible to developing eating disorders. For anyone with any history of any mental health diagnosis, fasting is generally not a good idea. This is also true for people searching for stress eating help and searching for nutritional neutrality. If fasting has led to signs of an eating disorder, reach out for help! 

When the brain/mind is susceptible to extremes, fasting sets up more extremes. This includes bingeing, loss of control eating, obsessing over food, and often guilt, shame, and other negative emotions. There comes a time in the wellness journey when the best thing to do is tune out “diet culture” and the influencers who may be different from you. Is it time to do you? Let’s figure out how to build your own nutritional identity and stand tall in your brand of dignity.

References

1. Welton S, Minty R, O’Driscoll T, Willms H, Poirier D, Madden S, et al. Intermittent fasting and weight loss: Systematic review. Can Fam Physician Med De Fam Can. 2020;66(2):117–25.

2. Patikorn C, Roubal K, Veettil SK, Chandran V, Pham T, Lee YY, et al. Intermittent Fasting and Obesity-Related Health Outcomes. Jama Netw Open. 2021;4(12):e2139558.

3. Currenti W, Godos J, Castellano S, Mogavero MP, Ferri R, Caraci F, et al. Time restricted feeding and mental health: a review of possible mechanisms on affective and cognitive disorders. Int J Food Sci Nutr. 2020;1–11.

4. Alvarez Y, Glotfelty LG, Blank N, Dohnalová L, Thaiss CA. The microbiome as a circadian coordinator of metabolism. Endocrinology. 2020;

5. Zheng D, Ratiner K, Elinav E. Circadian Influences of Diet on the Microbiome and Immunity. Trends Immunol. 2020;

6. Chellappa SL. Circadian misalignment: a biological basis for mood vulnerability in shift work. Eur J Neurosci. 2020;

7. Avena NM, Rada P, Hoebel BG. Evidence for sugar addiction: Behavioral and neurochemical effects of intermittent, excessive sugar intake. Neurosci Biobehav Rev. 2008;32(1):20–39.

8. Kreisler AD, Mattock M, Zorrilla EP. The duration of intermittent access to preferred sucrose-rich food affects binge-like intake, fat accumulation, and fasting glucose in male rats. Appetite. 2018;130(Neuropsychopharmacology 22 4 2000):59–69.

9. Cuccolo K, Kramer R, Petros T, Thoennes M. Intermittent fasting implementation and association with eating disorder symptomatology. Eat Disord. 2021;1–21.

10. Lowe MR, Whitlow JW, Bellwoar V. Eating regulation: The role of restraint, dieting, and weight. Int J Eat Disorder. 1991;10(4):461–71.

11. Hockey A, Barlow FK, Shiels AL, Donovan CL. Body dissatisfaction in midlife women: The applicability of the tripartite influence model. Body Image. 2021;39:202–12.

12. Wiss D. Clinical Considerations of Ultra-processed Food Addiction Across Weight Classes: an Eating Disorder Treatment and Care Perspective. Curr Addict Reports. 2022;1–13.