In Wireless Body Area Networks (WBAN), the subject characteristics (morphology, including gender, posture and movement) are among the main sources of the channel variability. The objective of this communication is to highlight statistically the influence of the anthropomorphic characteristics on the on-body channel. To do it, we have simulated five radio links on five homogeneous men subjects with different morphological characteristics. Experimental results obtained for some radio links have been used to support the relevance of the simulations. Within the framework of this first semi-quantitative approach, this communication is limited to the modeling of the Path Loss as a function of two quantitative morphological parameters that are the Body Mass Index (considering different body heights and fatness) and the Waist Circumference. The objective is to identify the main trends and to extract "semi-quantitative" models giving the orders of magnitude of the variability for each radio link. The latter typically ranges from 4 to 10.6 dB for the phantoms considered (except for a link for which the variations are limited to approximately 2 dB). This analysis is motivated by the importance of the variability obtained.