Effect of glycemic index on obesity control

Objective Evaluate the effect of glycemic index (GI) on biochemical parameters, food intake, energy metabolism, anthropometric measures and body composition in overweight subjects.Materials and methods Simple blind study, in which nineteen subjects were randomly assigned to consume in the laboratory two daily low GI (n = 10) or high GI (n = 9) meals, for forty-five consecutive days. Habitual food intake was assessed at baseline. Food intake, anthropometric measures and body composition were assessed at each 15 days. Energy metabolism and biochemical parameters were evaluated at baseline and the end of the study.Results Low GI meals increased fat oxidation, and reduced waist circumference and HOMA-IR, while high GI meals increased daily dietary fiber and energy intake compared to baseline. There was a higher reduction on waist circumference and body fat, and a higher increase on postprandial fat oxidation in response to the LGI meals than after high GI meals. High GI meals increased fasting respiratory coefficient compared to baseline and low GI meals.Conclusion The results of the present study showed that the consumption of two daily low GI meals for forty-five consecutive days has a positive effect on obesity control, whereas, the consumption of high GI meals result has the opposite effect. Arch Endocrinol Metab. 2015;59(3):245-51.

Use of the glycemic index in nutrition education / Uso do índice glicêmico na educação nutricional

Recently, the lack of studies providing practical guidance for the use of the glycemic index has been indicated as the cause of its little use in nutrition education. The aim of this study is to give instructions on the use of the glycemic index as a tool to be used in nutrition education to estimulate the consumption of low glycemic index foods. Studies published over the past 12 years, in addition to classic studies on this topic, found in the databases MedLine, ScienceDirect, SciELO and Lilacs exploring the importance of the glycemic index and the factors that affect the glycemic index were selected for this article. The preparation of lists grouping foods according to their glycemic index should be based on information found in tables and specific web sites. This is an interesting strategy that must be very carefully conducted, considering the eating habits of the assisted people. To reduce the postprandial blood glucose response, high glycemic index foods should be consumed in association with the following foods: high protein and low fat foods, good quality oils and unprocessed foods with high fiber content. Caffeine should also be avoided. The glycemic index should be considered as an additional carbohydrate-selection tool, which should be part of a nutritionally balanced diet capable of promoting and/or maintaining body weight and health.

Recentemente, a falta de artigos que visam fornecer orientação quanto ao uso do índice glicêmico foi apontada como causa de sua baixa utilização na educação nutricional. O objetivo do presente trabalho é oferecer suporte para o uso do índice glicêmico como ferramenta a ser adotada na educação nutricional, para estimular o consumo preferencial de alimentos que apresentem menores valores nesse indicador. Foram selecionados estudos publicados nos últimos doze anos, além de estudos clássicos referentes ao tema, indexados nos bancos de dados MedLine, ScienceDirect, SciELO e Lilacs, que exploraram a importância do índice glicêmico e os fatores que interferem em seu valor. A elaboração de listas agrupando os alimentos segundo o índice glicêmico deve ser feita com base nas informações encontradas em tabelas e sites específicos. Essa é uma estratégia interessante que deve ser conduzida de maneira criteriosa, considerando-se os hábitos alimentares do público assistido. Para resultar em resposta glicêmica pós-prandial mais baixa, os produtos de alto índice glicêmico devem ser ingeridos em associação com alimentos ricos em proteína e pobres em gordura, com óleos de boa qualidade, com alimentos menos processados por ricos em fibras, evitando-se os com alto teor em cafeína. O índice glicêmico deve ser considerado uma ferramenta adicional para a escolha de alimentos fonte de carboidratos, os quais devem ser incluídos em uma dieta nutricionalmente equilibrada, capaz de promover e/ou manter tanto o peso corporal adequado quanto a saúde.