Food intolerance in patients with chronic fatigue.

Intolerance to various foods is reported often by patients seeking evaluation for chronic fatigue, a common symptom in primary care practice. To assess the prevalence and significance of this phenomenon we studied 200 consecutive patients with chronic fatigue who were given a comprehensive medical and psychiatric evaluation. Intolerance to foods from at least three different groups was reported by 27 patients (13.5%). We compared these patients with 27 age- and gender-matched patients from the same cohort of fatigued patients. Physical examination and laboratory testing showed few abnormalities in either group. The two groups were similar with respect to the duration and severity of fatigue, lifetime depressive symptoms, and prevalence of current depressive disorders (67% vs. 63%) and anxiety disorders (11% vs. 15%). Patients with multiple food intolerance had more lifetime functional somatic symptoms (p < .05) and a significantly higher (33% vs. 7%) prevalence of somatization disorder (p < .025). These data suggest that intolerance to multiple foods is probably not a cause or the effect of chronic fatigue, but rather one of the manifestations of the somatization trait expressed in these patients.