Gastric bypass (GBP) may have a weight-loss independent effect on cardiometabolic risk factors (CMRF). We compared the effects of GBP and an isocaloric very-low-energy diet (VLED) on body composition and CMRF.


Non-randomized, single-center study, 3-week run-in-phase with a low-energy-diet (<1200 kcal/d) followed by GBP or 6-week VLED (<800 kcal/d). Statistics: Independent and dependent samples t-test, Mann-Whitney U test and ANCOVA; between-group differences adjusted for % weight-loss and baseline values.


Seventy-eight subjects (52 women), mean (SD) age 48 (10) years, weight 128 (24) kg, BMI 43 (6) kg/m2, underwent GBP (n=40) or VLED (n=38). Mean 9-week weight-losses were 16.7 (3.6) and 13.9 (4.6) kg, respectively, P=0.005. Fat-mass was reduced by 12 (3.4) and 10.8 (3.5) kg, P=0.15, and fat-free mass by 4.7 (3.2) and 3.1 (2.2) kg (P=0.018). Baseline-values of CMRF did not differ significantly between groups, while total-cholesterol and LDL-cholesterol declined significantly more in the GBP-group (Table).


Our results support the hypothesis that GBP reduces LDL-cholesterol independent of short-term weight-loss.