At this point in the resolution-heavy month, many of us may be trying to shed pounds, either the ones we added during the holidays or the ones we’ve accumulated stealthily with time. But by the end of the year, most of us won’t have succeeded — and there’s not much established science to tell us why.

An ambitious new study published this month in Cell Systems, however, promises to shed some new light, enumerating for the first time the thousands of changes in genes and various biological systems that may occur after even a small amount of weight gain, and which may — or may not — be reversed if the weight is then dropped. The findings may help researchers better understand why adding weight causes some people to develop diabetes and other conditions, and also underscore the cumulative health risks of so-called yo-yo dieting.

An international consortium of scientists approached 23 overweight men and women who were already part of a large, continuing study — called an “omics” study in the parlance of researchers — that examines participants’ genomes and microbiomes and generates vast amounts of data about the workings of the body.