Food is one of the most important aspects of development and growth. While growth is a continuous phenomenon, the pace or speed and the qualitative and maturation changes are different in the various stages of life. Since birth, one can distinguish three different stages of growth and therefore nutritional requirements vary. THE FIRST YEAR OF LIFE During the first year of life, a baby triples its initial weight and its height increases 50%. Breastfeeding is still recommended as the best way to feed the baby as it provides all the nutrients necessary for their growth and development as well as anti-bacterial and anti-infection agents for its immune system. At around 6 months solid foods are gradually introduced starting with cereals then continuing with fruits, vegetables and meat. It is important to ensure an adequate intake of iron, for example, with fortified cereals and minced meat. PRE-SCHOOL It is at this time of life the habits that will later indicate the state of health are acquired. It should be ensured that children have a varied diet and of all types of foods included in their diet so that they get used to different flavours and textures. Until 2 or 3 years old almost all children go through a phase of decreased appetite due to a decrease in energy demand. Children should not be forced to eat more than is necessary because it can cause a rejection response to food. SCHOOL AGE At this age, as in the former, it is essential to eat regularly; five meals a day and not to forget breakfast. The energy and calories obtained from breakfast are incredibly important since they will provide an adequate intake, as much physically as intellectually, for their school and daily work tasks. It is also important to consume dairy products and vary a wide range of foods such as meat from different species, fish, 4 or 5 eggs a week, pasta and rice, pulses, vegetables and greens. Children should be encouraged to eat fresh fruit and eat more bread since the carbohydrates provided help to balance the diet. Children need to drink plenty of fluids, especially when it is very hot or if doing a lot of physical activity, and moderate consumption of sweets and soft drinks. TEENAGERS At this stage, the nutritional requirements are altered due to the growth spurt that occurs during puberty between 11 and 15 years for girls and between 13 and 16 years in boys. Therefore special attention must be paid to sources of iron (lean meat, fish, beans, green vegetables, dried fruits and fortified cereals) and calcium (milk, yogurt and cheese). As for iron, eating more lean meats, fish, beans, green vegetables, nuts and cereals fortified with iron is recommended. In addition to an adequate intake of calcium for strong bones it is necessary to ensure the intake of vitamin D and phosphorus, and to do physical exercise.