Replacing added sugars in beverages and foods with low-calorie sweeteners (LCSs) is one strategy to reduce calories and manage body weight. There are few studies on LCS consumption by product category and by consumer socio-demographic status. Data for a representative sample of 22 231 adults were obtained from five cycles of the National Health and Nutrition Examination Survey (1999-2008 NHANES). A single 24-h recall was used to identify consumers of LCS beverages, foods and tabletop sweeteners. Time-trend analyses were conducted for total LCS consumption and for LCS beverages. Approximately 30% of US adults consumed some type of LCS, with 19.5% consuming LCS beverages, 11.4% consuming tabletop LCS and 4.6% consuming LCS foods. LCS consumption by product category peaked at different ages, with older adults more likely to consume tabletop LCS and LCS foods. In age-adjusted analyses, LCS consumers in every product category were more likely to be women, 45-65 years old, non-Hispanic whites, US-born adults, college graduates and with higher household incomes. Predictors of LCS consumption were not altered upon adjustment for body mass index and diabetes status. LCS consumption from all sources and from LCS beverages increased between 1999 and 2008. LCS use was more common among populations with a lower burden of obesity and related chronic disease, specifically, non-Hispanic whites and those with more education/higher incomes. The reasons for this observed paradox are complex and merit additional research.