Short sleep duration is associated with high energy and total lipid intake in obese women: a pilot study / A curta duração do sono está associada ao elevado consumo energético e de lipídios totais em mulheres com obesidade: um estudo piloto

ABSTRACT Objective To evaluate the influence of self-reported sleep duration on ghrelin secretion and nutritional indicators in obese women. Methods This is an observational study, including 36 adult women with obesity. Sleep duration was reported while completing the general questionnaire. Dietary, laboratory, anthropometric, and body composition indicators, and resting metabolic rate, were evaluated. For statistical analysis, sleep duration data were grouped into tertiles: less than six (first tertile); equal to or above six; and less than eight (second tertile); equal to or greater than eight hours of sleep per day (third tertile). The indicators were compared for the different ranges of the sleep duration. Results There was no significant difference when comparing anthropometric, laboratory, and energy expenditure indicators between sleep tertiles. However, women with shorter sleep duration (less than 6 hours per day) had a higher mean caloric intake, compared with the tertile of eight hours or more of sleep per day. For total lipid intake, the mean consumption was higher in the first tertile (up to six hours a day). Conclusion Sleeping less than six hours a day led to an increase in energy and lipid intake in obese women. However, it did not change the plasma ghrelin concentration.

RESUMO Objetivo Avaliar a influência da duração de sono autorrelatada na secreção de grelina e indicadores nutricionais na obesidade. Métodos Trata-se de um estudo observacional, incluindo 36 mulheres adultas com obesidade. A duração do sono foi relatada durante o preenchimento do questionário de dados gerais. Foram avaliados indicadores dietéticos, laboratoriais, antropométricos e de composição corporal, além da taxa metabólica de repouso. Para análise estatística, os dados de duração de sono foram agrupados em tercis, sendo menor do que seis (primeiro tercil), igual ou acima seis e menor do que oito (segundo tercil), igual ou maior do que oito horas de sono por dia (terceiro tercil). Os indicadores supracitados foram comparados entre as diferentes faixas dos tercis de duração de sono. Resultados Não houve diferença significativa ao comparar os indicadores antropométricos, laboratoriais e do gasto de energia, entre os tercis de sono. Porém, mulheres com menor tempo de duração do sono (menos de 6 horas por dia) apresentaram maior média da ingestão calórica, comparado com o tercil de oito horas ou mais de sono por dia. Para a ingestão de lipídios totais, a média de consumo foi maior no primeiro tercil (até seis horas por dia). Conclusão Dormir menos do que seis horas por dia levou ao aumento na ingestão energética e de lipídios em mulheres com obesidade, porém, não alterou a concentração de grelina plasmática.

Hypocaloric diet with lower meal frequency did not affect weight loss, body composition and insulin responsiveness, but improved lipid profile: a randomized clinical trial.

Dietary approaches are essential to control obesity, but the effectiveness of changes in meal frequency (MF) as a strategy for body weight loss or maintenance remain unclear. This study aimed to evaluate the influence of MF of a hypocaloric diet on weight loss, body composition, active ghrelin levels and metabolic indicators of obese women. This is a randomized, parallel clinical trial, including 40 women divided into two groups that received a hypocaloric diet with different MFs: MF6: six meals per day, and MF3: three meals per day. Dietary, laboratory, anthropometric and body composition indicators were assessed, as well as energy expenditure (EE), before and after the 90 days of the intervention. Dietary consumption did not differ between groups, before or after intervention. The two groups reduced their energy intake after intervention, but there were no differences between the groups. Waist circumference (WC) was reduced and resting metabolic rate had increased in the MF3 group at the end compared to baseline. Moreover, there was a significant difference in the triglyceride levels between groups after intervention, with an important reduction in the MF3 group, although changes in body composition, blood glucose, plasma ghrelin levels and EE variables did not differ between the groups at the end. It is concluded that, the hypocaloric diet with different MF each day did not change weight loss, body composition or insulin responsiveness, but there was an improvement of triglyceridemia in the MF3 group. The present study suggests that eating snacks between meals is not an important factor for weight loss and improvement of metabolic health in women with obesity.