Abstract
Diet-resistant weight disturbances (either underweight or overweight) are a common feature in polysymptomatic patients with multiple intolerances. This paper examines the changes in weight occurring during in-patient investigation in an environmental unit and after discharge in 28 patients with long histories who reported that they had improved substantially. Patients overweight on admission had lost weight and those underweight on admission had gained weight at follow-up ($rH= — 0.62, p < 0.-01). All patients showed evidence of fluid loss during the therapeutic fast (more than 3.5 kg in nine patients), and of transient weight gains following food challenge. Chronic intolerances affect body weight by causing both fluid retention and disturbance of weight homeostasis; the evidence that they are caused by atypical allergic responses is discussed.