Introduction: There is an increasing amount of data relating the dietetic pattern to health variables, although data concerning the child population are scarce. The aim of the study is to assess the effects of affinity to the Traditional Mediterranean Diet (TMD) pattern, together with breastfeeding, on the incidence of childhood asthma and inflammatory and recurrent diseases in children under two years of age. Methods: Quasi-experimental intervention study, where breastfeeding was promoted and following the TMD pattern was offered. The incidence of morbidity was evaluated and correlated with the dietary patterns which were followed. According to their adhesion to the TMD-Breastfed Test patients were classified into two groups: Group-1 (greater affinity) and Group-2 (lower affinity). Results: The score of the TMD-Breastfed Test was optimal in group-1 and good in group-2. It shows a marked reduction in both consultation groups “on request” compared with “planned”, with low morbidity and low use of antibiotics. The incidence of infectious diseases and bacterial complications shows a clinically relevant difference between both groups. The incidence of childhood asthma was greater in group-2, with less adherence to breastfeeding. Conclusions: In these cohorts of breastfed patients with good adherence to TMD patterns, there was evidence of a low incidence of infectious diseases and childhood asthma, more pronounced in the breastfed group. Adapted milk and other foodstuffs of animal origin have been linked to being able to cause inflammatory and recurrent diseases, as their dietary limitations have contributed to decreasing morbidity.