Chylomicron particles are continually synthesised and secreted from the intestine even in the absence of ingested fat. It is possible that following consumption of low doses of fat the basal level of chylomicron secretion and subsequent metabolism are sufficient to metabolise this fat without an increase in postprandial chylomicron concentrations. To test this hypothesis, healthy male subjects were randomised to receive, on three separate occasions, meals containing a range of doses of fat (average 8·1–19 g) and effects on postprandial lipaemia and chylomicron concentration were determined. Furthermore, to delineate the effect on lipid-rich v. lipid-poor (remnant) forms lipid levels were also determined in a density <1·006 g/ml fraction. Following consumption of the very low dose of fat the postprandial concentration of chylomicrons was unaltered, whereas following the medium dose postprandial chylomicron concentrations were significantly increased. Interestingly, this increase was only detected in the lipid-rich chylomicron fraction, with postprandial levels of chylomicron remnants remaining unchanged. In conclusion, it appears that consumption of what would be considered low to medium doses of fat are not associated with transient postprandial increases in chylomicron remnants in healthy male subjects.