People don't tend to want to know the truth when it comes to dieting and beauty. People don't tend to trust science unless it's slagging off religion. As such, TV has had something of an identity crisis. It showed us Grow Your Own Drugs and You Are What You Eat. The adverts on commercial channels showed us pentapeptides and things that had Deep Beauty Skin Science (tm) and the like. No-one, it seemed, was willing to much about it other than say "it all seems like a crock to me!" Well, one person who has been applying logic and science to such matters is Professor Regan, who will host a new show this week called Professor Regan's Diet Clinic (Channel 4, Thursday, 16 April, 9pm). She's appeared before on our screen, pulling apart the guff that adorns the world's beauty creams and lotions... but this time, she's getting a whole series to do it in.