Periodontal disease is ranked among the 10 most prevalent chronic diseases worldwide, and is considered a major public health problem. Its etiology has been associated with local and general conditions that could interfere in the host immune response. Obesity, like periodontal disease, has emerged as a prevalent chronic disease in high-, low- and medium-income countries, recognized as risk factor for cardiovascular disease and cancer. A relationship between periodontal health and obesity may exist, but the mechanism that would explain this association remains unclear. Life-course epidemiology could be a useful instrument to investigate a casual association between early exposures and later outcomes, being appropriate for understanding the establishment of chronic conditions. This approach comprehends different theories, considering the time, the duration and the intensity of early exposition, and its impact on the development of chronic diseases in later life. Thus, the aim of this study is to hypothesize the different life-course epidemiology theories to explain the possible association between periodontal health and nutritional status in adulthood.