-Background -Changes in digestion and nutrients losses are relevant aspects in weight reduction and maintenance of the nutritional status of patients undergoing gastroplasty, but few studies are available in the literature. Aim -To study the systemic changes arising from the reduction in weight over time after surgery. 28,93 and 35,89). The percentage of weight reduction at this stage was 36,31% (p>0,001), one patient had weight gain, in three (6,8%) patients the albumin level was reduced and nine had anemia. The faecal fat was positive in 16 patients (36,4%), reducing substance in stool was positive in one patient and the presence of faecal occult blood was positive in 13 patients (29,5%). The internal diameter of the silicon ring was between 0,45 and 1,4 cm (mean 0,75, SD = 0,22). Conclusion -After surgery there is a significant weight loss, but the BMI is still above 35 kg/m² in 26 patients (59%), followed for a long time. There is a substantial improvement in cholesterol and glucose blood levels. The diameter of ring in the small stomach showed no significant association with weight reduction, while patients with greater than 1 cm ring did not show anemia or low levels of albumin, clinically better than those with rings smaller than 1 cm.RESUMO -Racional -As alterações na digestão e perdas de nutrientes são aspectos relevantes na redução do peso e na manutenção do estado nutricional do paciente submetido à gastroplastia, mas poucos estudos estão disponíveis na literatura. Objetivo -Estudar as alterações sistêmicas decorrentes da redução de peso ao longo do tempo, após o tratamento cirúrgico.