I can't help but feel that a discussion on the merit of BMI is a digression, from the OP's question. In addition, to being of no relevance to "R Programming".
In relation to Richard's technical comments: As per my previous post, it is possible to get *relative" measures. (Assuming the images are not on a standardized scale, which they could be). In relation to Jim's anatomical comments: An improved algorithm could evaluate a subject's body type. In addition to factoring in gender, ethnic characteristics and age. In any case, I don't see why image-based classification is any less worthwhile than conclusions based on timeseries plots and scatterplots... ______________________________________________ R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.