How to Consider Fasting Appetite Hormones in ARFID
How can clinicians use fasting CCK and ghrelin findings to interpret symptom patterns and follow-up in youth with ARFID?
Youth with ARFID may present with low appetite, early satiety, and clinically significant restriction, but these features do not necessarily reflect the same biologic process. This study suggests that fasting CCK and ghrelin may map onto different symptom domains over time, which can help clinicians frame biologic interpretation when monitoring ARFID symptoms.
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Define the ARFID symptom domain you are tracking
Separate lack-of-interest symptoms from overall ARFID severity before interpreting appetite hormones. In this study, lack of interest was assessed with the PARDI lack-of-interest scale, while overall ARFID severity was assessed with the PARDI severity scale covering food restriction and associated medical or psychosocial consequences.
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Identify whether the presentation includes lack of interest in eating
Assess whether the patient meets the clinical cutoff for the ARFID lack-of-interest presentation using a structured interview approach such as the PARDI, as was done in the study. The lack-of-interest phenotype in the article was characterized by low drive to eat, eating feeling like a chore, forgetting to eat, and early satiety after small portions.
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Obtain fasting hormone samples under standardized conditions if available
If fasting appetite hormone assessment is being pursued, align collection with the study conditions as closely as possible: overnight fasting with water permitted before blood draw. The article evaluated fasting plasma total CCK and ghrelin at baseline and at follow-up visits occurring about 12 months apart over 2 years.
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Interpret fasting CCK in relation to lack-of-interest symptoms
Use fasting CCK primarily as a possible correlate of lack-of-interest symptoms rather than of overall ARFID severity. In this study, youth meeting cutoff for ARFID-lack of interest had significantly higher fasting CCK only at Year 1, and greater decreases in fasting CCK from baseline to Years 1 and 2 were associated with greater decreases in lack-of-interest severity at both follow-ups.
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Interpret fasting ghrelin in relation to overall ARFID severity
Use fasting ghrelin primarily as a possible correlate of overall ARFID severity rather than of the lack-of-interest symptom dimension. The study found no significant ghrelin differences between those with and without the lack-of-interest presentation, but greater increases in fasting ghrelin from baseline to Years 1 and 2 were associated with greater decreases in overall ARFID severity at both follow-ups.
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Adjust your interpretation for major confounders used in the study
Interpret any hormone-symptom relationship alongside age, sex, and BMI percentile, since these were treated as relevant covariates in the analyses. For longitudinal interpretation, the study also accounted for baseline PARDI scores, emphasizing that change over time should be interpreted in the context of baseline illness severity.
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Avoid using hormone findings as standalone treatment decisions
Do not treat fasting CCK or ghrelin results as diagnostic tests or as direct indications for medication selection. The article was observational, found differential associations rather than causality, and stated that no standardized pharmacologic treatments for ARFID currently exist, although CCK antagonists and ghrelin agonists were proposed only as future research targets.
Clinical Considerations
- The study was observational, so hormone changes cannot be assumed to cause symptom changes.
- Follow-up endocrine data were reduced by attrition and sampling limitations, with hormone analyses including 56 participants at Year 1 and 43 at Year 2.
- The analyses did not control for co-occurring ARFID presentations, which may matter because presentation overlap is common in treatment settings.
- The sample was predominantly White and drawn from a single center, which limits generalizability.
Bottom Line
In youth with ARFID, falling fasting CCK tracked with improvement in lack-of-interest symptoms, while rising fasting ghrelin tracked with improvement in overall ARFID severity, so interpret these hormones as symptom-domain correlates rather than interchangeable biologic markers.
