"Yes, burgers certainly provide protein and calories," says Natalie Savona, author of The Kitchen Shrink (Duncan Baird Publishing, £10.99), "but you have to think of the quality of those calories. If you just want to give children some protein and calories, you can do that with a protein drink. Most commercially made burgers are not of high quality. You wonder which part of the animal the meat has come from, whether the meat is mechanically recovered, and whether the burger contains fillers or additives. Commercial burgers are also high in saturated fats and are usually high in salt.