*3.3.1 Class I obesity (< 30 BMI)*

For patients with BMI < 30 kg/m<sup>2</sup> , a meta-analysis (12 studies, including 697 Asians) found that at 12 months postoperatively, BMI and waist circumference were reduced by 2.88 kg/m<sup>2</sup> and 12.92 cm, respectively [61]. There was a significant improvement in glycemic control, lipid profiles, and β-cell function in the short and medium terms (6–24 months) [61]. A study of 25 Asians with T2DM and BMI of 23.23 to 29.97 kg/m<sup>2</sup> showed that the complete remission rates at 3, 6, and 12 months postoperatively for T2DM were 40%, 60%, 68% respectively, hypertension (22.2%, 50%, 75% respectively), hypertriglyceridemia (66.7%, 66.7%, 100% respectively), and hypercholesterolemia (41.7%, 60%, 100% respectively) [63].

#### *3.3.2 Class II obesity (<35 BMI)*

In a randomized controlled trial where 34% of the patients had BMI < 35 kg/m<sup>2</sup> , WL and diabetes remission were greater post LSG than after conventional treatment, and were comparable to RYGB [64]. Midterm follow-up (3 years) of 252 patients with BMI < 35 showed %EWL of 75.8% [65]. Insulin resistance remitted in 89.4%, dyslipidemia in 52%, NAFLD in 84.6%, hypertension in 75% and GERD in 65% [65]. T2DM showed 60% complete remission and 40% improvement [65].

The morbidity rate was 2.4%, two patients required reoperations, and no leaks or mortality were reported [65]. This suggests that LSG in patients with BMI < 35 kg/m2 is safe and effective, and BMI should not be the only indicator to consider BS. Further studies with longer follow-ups are required.
