BACKGROUND: the relationship between nutritional status, oral breathing and body posture. A balanced diet can provide adequate nutritional status that certainly contributes to a desirable condition of posture and nasal breathing for the subject. With regard the respiratory and breathing in children, since there is more change in sleep, decreased carbohydrate intake and increased intake of lipids, there may be also an association between oral breathing and nutritional status. PURPOSE: to illustrate the possible relationships between nutritional status, body posture and oral breathing in children, through a theoretical study. CONCLUSION: according to the reviewed studies, it is obesity, among nutritional disturbances, which generates a larger number of musculoskeletal disorders, such as impeding the control of body posture. We conclude that despite strong theoretical arguments seeking to explain a possible influence of mouth breathing on nutritional status, field studies, up to date, have failed to confirm this hypothesis, for this reason it is relevant to continue the research on these relationships.