The fatty meal test: an alternative to stool fat analysis.

In view of the technical difficulties inherent in using stool fat estimations as a parameter of malabsorption, we used a fatty meal absorption test. Children under investigation for failure to thrive were divided into two groups, those having a normal stool fat output (less than 3.2 g/day) constituting the control group, and those having steatorrhea. After a fatty meal containing 25 g of margarine and 25 g of butter fat, we measured the rise of serum triglycerides and chylomicrons hourly for 5 h. Serum triglyceride rise of less than 100 mg/dl or less than 100% above basal values and the appearance of less than 7% of chylomicrons were considered pathological. Of our control group 95% had a normal rise of triglycerides; and 96% of our patients with steatorrhea had an abnormal rise. This test was more reliable than the two-point triglyceride test previously described for the diagnosis of fat malabsorption. The fatty meal test as described here is considered to be a useful test of absorptive function.