The Side Effects of Restrictive Elimination Diets

Why are so many quick to criticize diet culture yet eager to embrace elimination diets?

To be fair, there are notable differences between the flashy fad diets advertised on tabloids and the therapeutic diets guided by knowledgeable functional medicine practitioners.

However, if we take a step back and consider the psychological implications of restrictive dieting as a whole, elimination diets often appear to cause more harm than healing.

Functional health practitioners have a duty to understand and communicate to their clients the psychological side effects of restrictive elimination diets.

What is a restrictive diet?

A restrictive diet is an eating pattern that restricts specific foods or food groups for a temporary or extended period of time. 

It can be voluntary or prescribed, fad or therapeutic. Many therapeutic restrictive diets involve an elimination phase, which is intended to identify problematic foods that are aggravating gastrointestinal, psychological, immunological, or hormonal symptoms.

The rationale is that temporarily removing potential “trigger” foods allows the immune system to regulate, the microbiome to balance, and the gastrointestinal (GI) tract to regenerate. Ideally, some or all eliminated foods can be reintroduced once symptoms have calmed and the gut has healed. 

This approach is methodical and straightforward in theory. However, we do not always consider how a short phase of restriction can ripple into consequences more significant than the initial symptoms.

It is essential for functional medicine practitioners to understand how (even temporary) restriction can feed food fear, distort body image, and promote disordered eating far into the future.

Why would someone adopt a restrictive diet?

Restrictive diets are recommended and adopted for a variety of philosophical, physical, and practical reasons. 

One of the primary reasons for restrictive dieting is to manage GI-related conditions, such as Celiac disease, inflammatory bowel disease (IBD), autoimmunity, or food allergies. 

Individuals with a GI condition are more than twice as likely to be on a restrictive diet [1], and up to 90% of patients with irritable bowel syndrome (IBS) symptoms report restricting foods to manage symptoms [2][3]. 

Women with a university education and higher socioeconomic status are also more likely to be on restrictive diets, regardless of having a GI condition [1][4]. Many women adopt restrictive diets because of low body satisfaction [5], fad popularity, or the perception that “a therapeutic diet must be healthier”. This mainstream self-prescription often occurs without a full understanding of the potential consequences.

What are the consequences of restrictive diets?

Beyond the physical effects on GI function, weight, nutrient status, and microbiome composition (all for better or worse), food restrictions can have a profound effect on psychological health.

Simply having a food allergy or GI condition can negatively impact social and psychological health in both children [6][7] and adults [8]. Social eating becomes something to be “navigated” rather than enjoyed [9]. Having GI symptoms increases an individual’s risk of developing a hyper-awareness of health, emotional eating behaviors, and health anxiety [10]. 

Furthermore, eating restrictively to manage GI symptoms further disposes an individual to disordered eating. 

Research reports that 40% of adolescents with IBS and 53% with Celiac disease exhibit maladaptive eating behaviors—such as skipping meals, vomiting after eating (not weight related), and restricting foods— to manage symptoms. These disordered eating behaviors can increase gut issues, decrease quality of life, and increase social isolation and stigma [11][2].

Restriction can increase food anxiety and cause an associated stress response to eliminated foods. Patients with high levels of food anxiety are more likely to over-restrict [9]. Avoidance reinforces the fear that food will cause harm, making future reintroductions difficult. 

For example, if someone temporarily eliminates nuts, they will likely perceive nuts as “unsafe”. When it comes time to reintroduce nuts, the subconscious stress response associated with nuts may cause an adverse reaction (rather than the nuts themselves). 

If the aim of a dietary intervention is to maximize nutrient diversity and promote whole-person wellness, then we as practitioners need to be aware of how unnecessary restriction can work against those ultimate goals.

Do restrictive diets improve quality of life?

One attractive feature of restrictive dieting is that it gives a sense of control in cases of chronic conditions. But what if that sense of control is just an illusion? Ultimately, do restrictive diets improve a patient’s overall quality of life (QOL)?

They do not seem to.

One study found that IBD patients following a gluten-free or vegetarian diet believed their restrictive diet was helping their disease course, but there were no measurable differences in disease activity, hospitalization, or surgeries. Instead, these patients reported increased anxiety, depression, and/or post-traumatic stress as a result of restriction [12].

Another study assessed how restrictive dieting impacted QOL measures such as sleep, energy, food intake, social functioning, and physical status. Not surprisingly, the researchers found that having a GI or mental health condition decreased health-related QOL. Despite the perceived benefits of restrictive dieting, it did not improve QOL in those with a GI condition. In fact, following a restrictive diet was associated with lower QOL across the board [1].

A similar trend was observed in IBS patients: as food restrictions increased, QOL decreased [13]. Yet another study found higher rates of depression and anxiety and lower QOL scores in patients with Celiac disease on a gluten-free diet [4].

At this point, an attentive scientist would ask: is it possible that QOL decreases not because of the restriction itself, but rather the need for restriction? Is QOL more directly impacted by the diet or the condition?

Perhaps neither—it seems to be the perception of the diet. 

QOL was found to trend downward as the perceived difficulty of diet adherence went up. In other words, if you think it is challenging to follow a restrictive diet, that has more negative impact than if you think it is easy [4].

Do restrictive diets promote disordered eating?

Restrictive diets—no matter how “therapeutic”— should be contraindicated for individuals with a diagnosable eating disorder such as anorexia nervosa, bulimia nervosa, binge eating disorder, or avoidant/restrictive food intake disorder.

While not (yet) included in the DSM V, orthorexia is gaining attention as a disordered eating condition often seen in individuals who are very attentive to their health. It is defined as an “obsessive focus on “healthy” eating and inflexibility in diet, which leads to clinically significant medical or psychosocial impairment” [14]. 

In other words, orthorexia is “pathological healthy eating”, with symptoms similar to anorexia nervosa and avoidant/restrictive food intake disorder. Over time, it can cause nutrient deficiencies, gut dysregulation, and endocrine imbalances.

The nature of restrictive dieting promotes a greater attentiveness to food intake and susceptibility to food anxiety. Prescribing a restrictive elimination diet to an individual inclined to orthorexia may change their idea of “healthy”, resulting in hyper-awareness of their health [15]. This is something all practitioners need to be acutely aware of, especially if prescribing food restrictions.

What starts as a therapeutic intervention for a GI issue may end up as an unhealthy obsession with food. In the long run, the psychological consequences of restrictive eating may be more damaging than the initial symptoms one sets out to address.

In Conclusion

The psychological consequence of food restriction must not be overlooked.

Functional health professionals have an important responsibility to weigh the pros and cons of restrictive diets before prescribing them to their clients. Just as all health recommendations should consider bioindividuality, so should the recommendation for any type of restrictive dieting. 

It is critical that all potential psychological side effects are understood, assessed, and communicated before anyone adopts a restrictive diet.

Bioindividual Screening Questions for Restrictive Dieting

• Does this individual have a history of or tendency towards an eating disorder or orthorexia?
• Will an elimination diet promote disordered eating or orthorexia in this individual?
• How will restricting foods impact how this individual thinks about food?
• How will restricting foods impact how this individual thinks about their body?
• How will this individual respond when they “break” their diet or eat a restricted food? Will that promote an unnecessary sense of guilt, shame, or failure in the healing process?
• How can I, as a practitioner, encourage the addition of foods, rather than elimination? How can I encourage dietary diversification, rather than restriction?
• Does my language promote unhealthy eating thoughts and behaviors? (i.e., rather than good/bad or safe/unsafe, use words such as optimal, nourishing, supportive, etc)
• How could this short-term elimination phase hinder the psychology of reintroductions?
• If a temporary elimination diet is necessary, what is the plan for
  • Preserving or increasing nutrient diversity?
  • Promoting a healthy relationship with food and their body?
  • Prioritizing reintroductions as soon as possible?

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Article Sources

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