Poor diet quality is associated with biochemical parameters of protein nutritional status after Roux-en-Y gastric bypass.

Objective: To assess diet quality and its association with body and biochemical parameters in patients who underwent Roux-en-Y gastric bypass (RYGB).

Methods: Prospective observational study with individuals of both sexes subjected to RYGB. Body composition, biochemical parameters, and diet quality were assessed before and six months after RYGB. Diet quality was assessed by the Healthy Eating Index (HEI). Data were analyzed by the paired t-test or Wilcoxon signed-rank test, with a significance level of 5%. Spearman's correlation and simple linear regression were performed between variables.

Results: The final sample included 34 patients. Their diet was classified as poor before and 6 mo after RYGB. BMI, fat mass, fat-free mass, waist perimeter, serum total protein, transthyretin, alpha-1-acid glycoprotein, and C-reactive protein decreased significantly (P < 0.05). Variations in the HEI score and caloric intake were associated with serum albumin and transthyretin (P < 0.05).

Conclusion: Poor diet quality was present before and six months after RYGB, and the study data suggest that poor diet quality is associated to a risk of loss of lean body mass and visceral protein six months after RYGB.