Goya is inimitable when there's a sort of bluntness in his brush, an immediacy that rides over the usual demands of taste. Sometimes I think that Goya knew as little about taste as an animal does.This is not just a fanciful remark. La Marquesa de Santiago y San Adrin (1804) was in aristocratic Spanish hands. And for any serious student of the artist, "Goya: un regard libre" is essential. It is not an enormous exhibition, since it contains only about 60 paintings.

These pictures have been chosen with extreme care and there are some telling rarities. First among them is a painting I had not encountered before and had not seen in reproduction. "Diets don't work" was Dale Winton's first fat-fighting principle. Is Fat Free a series of cautionary tales, then, or are its participants just figures of sadistic fun? Either way, we're left with an unpleasantly voyeuristic taste in the mouth Sometimes the BBC's scheduling is way off the mark.. No Goya painting can fail to be exciting.

So I recommend a visit to Lille and its Palais des Beaux-Arts, just a couple of hours by rail from Waterloo Its new survey of the Spanish master strikes to the heart I'm sorry that the show isn't coming across the channel. Of the slimmers we met on Thursday, one woman was on a strict diet-tablets-and-Black-Forest- gateaux regime. Another woman had progressed from "morbidly obese" to "clinically obese" via Total Food Replacement, which meant that she consumed nothing but three jugs of nutritional goop a day for seven months. A man was on a bamboozling diet involving a set number of "sins" per week and a choice of "red days" and "green days" (the dietician had to check that her clients weren't colour-blind). And in the next episode, we see a man who plans to lose 18 stone by having his stomach stapled. I don't know what that entails exactly, but I'm sure the words "stomach" and "staple" were never supposed to be in the same sentence.What are we to make of these telly tubbies? At another time of year, our instinct would be to cheer them on, but having tucked into the uncommon common-sense of Weight of the Nation, we already know that they're doomed to tragic failure. I've got this gland that makes me a greedy bastard." Turns out she was more or less right.Two days after Weight of the Nation came the first episode of Fat Free, a documentary series about five people on five different diets.