Nutrition is a science that is constantly the subject of curiosity and, as a result, has a large number of scientific publications. Based on the objectives of the research, it is essential to choose the right type of study in order to carry out quality work. In addition, they must generate results that are applicable in clinical practice and that also have a logical and scientific basis, adds Caryna Eurich Mazur, a nutritionist with a master's degree in Food and Nutritional Safety and a lecturer on the undergraduate and postgraduate courses at Campo Real College. According to her, the main studies in the field of nutrition are:
Intervention: is a study in which the researcher proposes to intervene in the life of the research subject in some aspect. For example, proposing that the individual supplements 2g of omega 3 a day and at the end of four weeks analyzing the improvement/benefit in biochemical and anthropometric results. In addition, intervention studies are widely used in doctoral theses, when the aim is to analyze a new product, or the indication of a new treatment, or the effectiveness of nutritional guidance. These studies are complete and widely accepted in scientific circles, with good validation and acceptance, says Caryna.
ObservationObservational studies are those in which the researcher only observes a given situation. For example, the aim was to check the percentage of overweight and obese children in a city's nursery schools. At the end of the study, it was found that more than half of the children had this condition. According to the nutritionist, the observational study can propose an intervention after a given observation and, in this case, nutritional education and guidance would be pertinent. These are studies used to obtain a snapshot of a certain population. They are important because, through them, it is possible to conduct further studies in order to delve deeper into the subject, she analyzes.
Systematic reviewUnlike the first two, when conducting a systematic review the researcher has no contact with the research subject. These are studies accepted as opinion-forming in the scientific community. The nutritionist says that a systematic review makes it possible to establish relationships between two factors, whether they are distinct or not. For example, the relationship between coffee consumption and the risk of developing type 2 diabetes mellitus. For this study, 30 articles were analyzed; from the results, it was possible to conclude that coffee consumption was associated with a decrease in the incidence of diabetes. Systematic reviews are recommended to find out whether or not there are causal relationships, he explains.
Meta-analysisMeta-analysis: According to Caryna, this is similar to a systematic review, except that in this case, statistical tests are proposed to determine whether or not a relationship has been established in the review. In addition, according to the professional, the articles are also rigorously selected and have greater validity within the scientific environment. For example, a meta-analysis of how the consumption of green tea can help to reduce body circumference. After applying statistical techniques, it was found that there was no association (p>0.05) between the consumption of green tea (in its various presentations) and the reduction in circumferences, she concludes.
