Throughout the ages, dietetics has been an important part of medicine, but for many centuries it included far more than nutrition alone. Nevertheless, this was the part that physicians studied most. Not only did they prescribe some victuals as materia medica, but even the way to cook them played a part: in other words, the first 'culinary' recipes were written by physicians, without any distinction amidst purely medical prescriptions. On the other hand, we find compilations of "medical" cooking recipes, the first cookery books, written by physicians. We know about such lost examples dating from as early as the 5th century BC. In the Low Countries, even in the 16th century these cookery books are mostly written by physicians. Their dietetics still leans on Galen's humoral doctrine and remains restricted to knowledge about food. From that moment the word acquires the restricted meaning it has nowadays.