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Updated: Aug 13, 2025

Roux-en-Y Gastric Bypass Operation in Rats
Published on: June 11, 2012
Usual dietary intake, physical activity, weight loss, and body composition after five years of Roux-en-Y gastric
Lara Pereira Saraiva Leão Borges1, Kenia Mara Baiocchi de Carvalho2, Teresa Helena Macedo da Costa2
1Graduate Program in Human Nutrition, Department of Nutrition, Faculty of Health Science, Campus Darcy Ribeiro, University of Brasilia, Brasília Federal District, 70910-900, Brazil. larasaraiva.nutri@gmail.com.
Objective:
To estimate usual dietary intake (UDI), physical activity (PA), and their association with weight loss and body composition in patients who underwent Roux-en-Y gastric bypass (RYGB) after five years in the Federal District, Brazil.
Methods:
We assessed anthropometry and body composition using bioimpedance, and dietary intake and PA with three nonconsecutive 24-h recalls. PC-Side was used to estimate UDI. Dietary patterns (DPs) were identified through principal component analysis, and association between UDI and PA with percentage of total weight loss (%TWL) and fat-free mass (FFM) through multinomial logistic regression.
Results:
Sample (n = 124) presented mean (SD) age of 48.9 (9.4) years, median (IQR) of 9 years (7-10) post RYGB, current BMI = 32.3 kg/m² (28.8-35.7), %TWL = 24.7% (10.9), and FFM = 45.1 kg (41.1-51.9). Mean usual energy intake of 1556 kcal/d, with adequate protein intake, poor fiber intake, and excessive carbohydrate, total fat, and added sugar intake, compared to dietary guidelines. Calcium, vitamins C, D, and E presented the greatest inadequacy (15%, 24%, 32%, and 49% of individuals, respectively, reported usual intake below EAR); 83 participants were considered active/very active, according PA. DP with high energy, protein, total fat, saturated fat, and sodium intake, was negatively associated with %TWL (OR = 0.545, p = 0.037). Protein intake was positively associated with FFM (OR = 1.091, p = 0.004). PA was not associated with %TWL or FFM.
Conclusion:
Participants demonstrated intake of carbohydrate, fat, fiber, added sugar not in accordance with guidelines. A DP rich in energy, protein, total fat, saturated fat, and sodium appears to decrease TWL. However, protein intake appears to increase FFM.
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