Bird nutrition has a very wide spectrum that has been studied in the ancient past (from the Roman Empire), first studying the diet of wild birds and then in captivity. They observe what they eat and how they eat in a way that they feed them in their gardens, which is still massively practiced in cities today. As the most common modeling organisms for nutrition research are often parrots because they are breeded as pets, but also poultry used in the food industry. However, these models are not relevant to the feeding of other bird species, such as those of a Passerine family who have other pre-requisitions of nutrition. Due to the high variety of foods, it is difficult to classify them in certain categories due to the diversity of food in the wild and the lack of nutrition. This paper presents a review of the diet of birds in nature and captivity (primarily insectivores, granivores and frugivores) and bird nutrition problems that breeders, veterinarians and rehabilitators can meet. In addition, this paper presents an overview of good and bad nutrition (quality of food, disease symptoms) in captivity and nurturing birds. In conclusion, there are many alternative mixtures that can replace the ongoing food in nature, but tends to be imitating the diet in the wild is difficult to make universal mixture that would satisfy all the alimentary requirements of birds. In addition, it should be noted which and what kind of mixture is given to which species of birds due to the diverse nutrition requirements of different bird species.