Fast food, fizzy drinks and larger portion sizes have all been blamed for rising levels of obesity. But figures obtained by the Guardian suggest changes to the recipes of many of our favourite foods could be to blame. Of a dozen leading brands for which we were able to compare nutritional information from a decade or more ago with today, nine showed an increase in calories, sugar or saturated fat.

Kellogg's Rice Krispies contain 36 more calories per 100g than in 1983 - an increase of about 10% - while Kraft Dairylea Triangles contain 15 more calories per 100g than in 2001, a 7% rise. While cheese used to be their main ingredient, followed by skimmed milk, whey and butter, it now comes third and accounts for just 16%.