Exposure quantification is a critical step in determining the dose of a pollutant reaching the human body, based primarily on the frequency, duration, and intensity of contact between the population and the substance. It relies on exposure scenarios in which numerical values for the various exposure parameters must be established. Currently, few French studies provide data for these parameters; American data are most often used instead. To help address this gap, a study was undertaken to describe body weight by sex and age within the French population using standard statistical parameters and probability distributions. Among all available data, the decennial health survey by the National Institute of Economic Statistics (INSEE) was selected because it is representative of the French population, with a sample of over 37,000 data points allowing for the adjustment of probability distributions by sex and age group. Data on body weight are self-reported rather than measured, which tends to underestimate the actual values. The theoretical distribution that best characterizes the variability of body weight is the log-normal distribution. Given changes in behaviors, particularly dietary habits, it is not possible to assign a validity period to these distributions.