[Comparative analysis of the glycemic response and glycemic index of instant mashed potatoes in subjects undergoing laparoscopic sleeve gastrectomy and control subjects].

BACKGROUND The laparoscopic sleeve gastrectomy (LSG) is a successful surgical procedure for morbid obesity. However, post surgery weight regain is usual, thus applying the glycemic index could promote good weight control. OBJECTIVE To compare the glycemic index (GI) and glycemic response (GR) obtained of instant mashed potatoes in individuals subjected to LSG versus control subjects. METHODS GI and GR were assessed in 10 LSG subjects and compared with 10 controls. GI methodology proposed by FAO/WHO was used; instant mashed potatoes as test food and white bread as standard food (50g available CHO). Capillary blood sample 0 (fasting), 30, 60, 90 and 120 minutes. The GI was determined by trapezoidal method. ANOVA was used to compare a factor between RG and IG groups; t-student to compare RG between foods. Statistical significance p<0.05. RESULTS The GR of instant mashed potatoes at 30 min was higher in the group operated (LSG 159,8 ± 25,9 versus control subjects 135,3 ± 17,3 mg/dl; p=0,023). In LSG group, the GR of instant mashed potatoes was higher than white bread at 30 min (159,8 ± 25,9 versus 136,3 ± 24,4 mg/dl respectively; p<0,01). The GI obtained from instant mashed potatoes was similar en both groups (LSG 119 versus control subjects 120; p=0,974). CONCLUSIONS Instant mashed potatoes despite having similar GI in both groups, generates higher glycemic responses in LSG group, and its consumption possibly favoring weight regain.