RESUMO
PURPOSE: The purpose of this study is to evaluate the effect of a high protein and low glycemic load diet in preventing weight gain after kidney transplantation. METHODS: We designed a prospective, single-center, open-label, randomized controlled study to compare the efficacy of a high protein (1.3-1.4 g/kg/day) and low glycemic load diet versus a conventional diet (0.8-1.0 g/kg/day of protein and no recommendations on glycemic load) in preventing weight gain (ClinicalTrials.gov identifier: NCT02883777). A total of 120 patients were evaluated. Patients were followed for 12 months, and the primary outcome was weight maintenance or weight gain lower than 5%. RESULTS: There were no differences in total energy intake, carbohydrates, and total fats between groups. Intervention group (IG) increased protein intake to 1.38 ± 0.56 g/kg/day and decreased the glycemic load to 87.27 ± 4.54 g/day, while control group (CG) had a dietary protein intake of 1.19 ± 0.43 g/kg/day and a glycemic load of 115.60 ± 7.01 g/day. Total fiber intake was greater and trans-fat was lower in IG. Dietetic cholesterol increased in IG over time and was significantly different between groups. Overall, patients had an increase in body weight over time, with a mean increment of 4.1 ± 5.5 kg (5.75%). The percentage of patients who achieved the primary outcome was 50% of sample size, without differences between groups. The glomerular filtration rate improved over time in both groups. Considering 24-h proteinuria and albuminuria, a similar rise was observed in both groups. CONCLUSION: The present dietary intervention was safe, but had no effect on weight gain in kidney transplant subjects. Our findings suggest that other strategies, including alternative dietary and/or pharmacological and psychological interventions might be tested in randomized control trials in order to improve patients' body weight outcomes after transplant.
RESUMO
BACKGROUND: Excessive weight gain is commonly observed within the first year after kidney transplantation and is associated with negative outcomes, such as graft loss and cardiovascular events. The purpose of this study is to evaluate the effect of a high protein and low glycemic-index diet on preventing weight gain after kidney transplantation. METHODS: We designed a prospective, single-center, open-label, randomized controlled study to compare the efficacy of a high protein (1.3-1.4 g/kg/day) and low-glycemic index diet versus a conventional diet (0.8-1.0 g/kg/day of protein) on preventing weight gain after kidney transplantation. A total of 120 eligible patients 2 months after transplantation will be recruited. Patients with an estimated glomerular filtration rate through the modification of diet of renal disease (MDRD) formula < 30 mL/min/1.73 m2 or urinary albumin excretion > 300 mg/24 h will be excluded. Patients' diets will be allocated through simple sequential randomization. Patients will be followed-up for 12 months with nine clinic appointments with a dietitian and the evaluations will include nutritional assessment (anthropometrics, body composition, and resting metabolic rate) and laboratory tests. The primary outcome is weight maintenance or body weight gain under 5% after 12 months. Secondary outcomes include body composition, resting metabolic rate, satiety sensation, kidney function, and other metabolic parameters. DISCUSSION: Diets with higher protein content and lower glycemic index may lead to weight loss because of higher satiety sensation. However, there is a concern about the association of high protein intake and kidney damage. Nevertheless, there is little evidence on the impact of high protein intake on long-term kidney function outcome. Therefore, we designed a study to test if a high protein diet with low-glycemic index will be an effective and safe nutritional intervention to prevent weight gain in kidney transplant patients. TRIAL REGISTRATION: ClinicalTrials.gov identifier, NCT02883777 . Registered on 3 August 2016.