It must be the Diet

The Not-so-Fat Controller, presiding over A Day out With Thomas at the Bo'ness & Kinneil Steam Railway.

We weren't being pulled by the engine dressed up as "Thomas" (these things have to be a bit circumspect about copyright apparently, so it wasn't totally a Thomas thing), but he was around for most of the day. good fun even in the rain - the wee man enjoyed it, along with his cousins.