Background: The effect of dietary calcium (Ca) on fecal fat excretion in lactose maldigestion is not known.
Objective: To investigate the effect of dairy and non-dairy dietary Ca on fecal fat excretion in lactose digesters and maldigesters during moderate energy restriction.
Design: A randomized cross-over trial comparing the effect of 500 mg versus 1500 mg dairy and non-dairy Ca on fecal fat excretion in 34 healthy adults during moderate (-30%) energy restriction induced weight loss for 12 weeks. The participants were classified as lactose digester or maldigester on the basis of breath hydrogen test.
Measurements: Anthropometric parameters and body composition, resting energy expenditure, energy and nutrient intake, fecal fat, physical activity, blood pressure, blood and urine sampling for pertinent measurements.
Results: Fecal fat loss expressed as percent of fat intake was significantly higher with 1500 mg (high Ca) as compared with 500 mg (low Ca) Ca intake per day (mean: 3.0%; 95% CI: 2.3 to 3.7%; P<0.001) independent of Ca source and lactose digestion status.
Conclusions: During a moderate energy restriction induced weight loss, a high-Ca diet causes an increase in fecal fat excretion independent of Ca source. Ca intake related fecal fat loss is also independent of the ability to digest lactose and it is not diminished over time (US Clinical Trial Registration: Clinicaltrials.gov NCT00808275).