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Updated: Dec 25, 2025

Roux-en-Y Gastric Bypass Operation in Rats
Published on: June 11, 2012
Impact of dietary patterns according to NOVA food groups: 2 y after Roux-en-Y gastric bypass surgery
Gisele Farias1, Robertah Maryanna Oliveira Silva2, Priscilla Peixoto Policarpo da Silva3
1Gastrointestinal Surgery Service of Hospital de Clínicas, Federal University of Paraná, Curitiba, Brazil; Departament of Nutrition, Faculdade Paranaense, Curitiba, Brazil.
Introduction:
Appropriate eating habits are crucial for sustained weight loss after bariatric surgery. A qualitative analysis of food consumption in the late postoperative period of bariatric surgery is thus advisable, even more so considering the increasing consumption of obesity-impacting ultra-processed foods.
Objective:
This study aimed to analyze the contribution of unprocessed, processed, and ultra-processed foods 2 y after Roux-en-Y gastric bypass (RYGB).
Methods:
This was a prospective study performed with 32 patients undergoing RYGB. Anthropometric and food intake data were analyzed. A food intake evaluation was conducted with a focus on quantitative and qualitative analyses. The latter was performed by categorizing food according to the NOVA classification.
Results:
There was a reduction in body mass, representing an excess weight loss of 83.80 ± 24.50% at 24 months postoperatively; and a reduction in calorie intake, macronutrients, fiber, and sodium after surgery. Regarding the qualitative analysis, 6 months after RYGB the calorie intake from processed and ultra-processed food decreased from 1398.47 ± 623.82 kcal to 471.80 ± 48.94 kcal (P < 0.05). However, between 6 and 24 months postoperatively there was an increase in 60.04% of the calorie consumption of these type of food (P < 0.01). The most important finding was that the consumption of processed and ultra-processed food exceeded 50% of the total calorie intake of the diet in all periods analyzed.
Conclusions:
RYGB promotes quick results in weight loss and a reduction of food intake, but the quality of food may affect long-term prognosis and deserves attention in the population studied. These results highlight the importance of dietary counseling aimed at guiding better food choices, in the interest of promoting sustained weight loss after bariatric surgery.
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