This study is saying that obese mothers produce offspring whose microRNA profile is altered. MicroRNAs are RNAs that regulate protein production in cells. According to this study, obese mothers alter their offspring's microRNA expression in such as way as to increase adipogenesis in the developing fetus. Adipogenesis is the formation of fat cells. So what they are saying, in short, is that if your mother is obese when she is pregnant with you, then you are (quite literally) born with more fat cells, and for an epigenetic-like reason, not because you just absorb more fat from your mom. This sucks for the next generation of kids who are going to be born the obese mothers of today. Fat begets fat, as I've speculated before. We need a social fat revolution. This is very dangerous for the future.