introduction:the non representative estimations of regular intake reduce the validity of an investigation. objectives:to determine which proportion of a group of adults who engage in a recreational physical activity keep food records of poor validity to estimate the regular energy intake. to determine whether the validity of the estimated energy intake is associated with certain characteristics of the respondents (sociodemographic and anthropo-metric, among others) methods:a cross sectional survey. the participants were adults between 19 and 70 years old, of both sexes, who did scheduled physical activity in four sports facilities in buenos aires city and buenos aires suburbs from july to september 2009. two interviews were made, anthropometric measurements were taken, and a 6-day food record and a physical activity record were carried out. in order to identify the non-representative estimated intake from the regular intake, we used the mc.crory et al. method, with a cut-off ± 1sd. results:out of 48 respondents, 31.3% (n = 15) kept a food record compatible with an underestimation of regular energy intake. 22.9% (n = 11) of the respondents kept a record that possibly overestimated energy intake. increased waist circumference and overweight have been associated with underreporting (p <0.01), whereas in the group that probably overestimated the intake there was a higher proportion of individuals with a higher educational level than secondary school (p <0, 05). conclusion:both under and overreporting were present in this group and must be taken into account while designing studies that use these tools.