Lentils have been staple rural rare in countries that grown them. Green lentils from Puy, France, for instance, are known as 'poor man's caviar'. In Italy lentils are lucky - particularly if you happen to hail from Castellucio in Umbria, where the local variety costs four times as much as humbler types. In the UK, meanwhile, they have more usually been seen as a bland food beloved only by vegetarians and anyone bold enough to tackle an Indian dahl. But Waitrose's sales indicate that reputation of the nutritious little legume, packed with protein, fibre, vitamins and minerals, is on the up. It reports that sales of organic green lentils at its 180-odd stores increased by 112 per cent in the last month, compared to the same period of 2006, and sales of organic red lentils by 83 per cent. The news may not be as spectacular as at first it sounds. Waitrose does represent the higher end of the UK supermarket experience, with stores located in areas where they are likely to attract the affluent middle-class shopper who places quality and nutritional value over cost. But trends that are adopted by the nutritionally- and socially-aware tend to trickle down to the mainstream. Witness the more availability of organic and fair-trade products - not to mention foods imbued with functional ingredients like omega-3 and probiotics. These, too, were once eyed warily by the vast majority of shoppers. (Bacteria? Fish oil in my bread? No thanks.) Now they are a positive selling point, turning up in even supermarket-own brand products that typically come in at a lower price point. There are no comparative figures on lentil sales from supermarkets more geared to serving the needs of the more price-sensitive Jack - Tesco, Sainsbury's, Morrison's and Asda. But once glance at the UK's mainstream media is enough to see that the message about the importance of following a balanced diet for health is everywhere - in politicians speeches, celebrity chefs' campaigns and, mostly starkly, in statistical reports that show the UK has the highest adult obesity rates in Europe (23 per cent, compared to below 10 per cent in France, Italy, Norway and Switzerland, according to the recent report Health Profile of England). The gathering interest in lentils is reminiscent of the oat revival that took place two or three years ago in the UK, as consumers started to take on board the benefits of eating foods with a low glycaemic index to maintain steady blood sugar levels. Since then, makers of oatcakes - appreciated largely, in the past, by dowdy great aunts - have seen their fortunes turnaround. Nairns, for instance, revamped its packaging and marketing strategy to appeal more to the health-conscious young and less to their Auntie Hilda. Figures released by the National Farmers Union and Home Grown Cereals Authority show that the fastest growing category in the UK cereal market is porridge, which is up 19 per cent year on year. And, according to a report from UK trade magazine the Grocer, sales of porridge oats have risen 5.4per cent to £47 (€71.6m) million in the last year with the instant oat varieties climbing 6.4 per cent to almost £64m (€97.5m).