According to a research article published in the New England Journal of Medicine, a leading international clinical journal, in November 2015, patients with severe obesity in adolescence who are able to undergo surgical weight-loss surgery at an early age not only lose a significant amount of their body weight (about a quarter of their body weight or more), but also have their other risk factors (hyperglycemia, hypertension, dyslipidemia, etc.) significantly corrected for the better, or even cured! The quality of life is significantly improved. As a result, the quality of life is significantly improved. I. What is surgical weight loss surgery? There are two types of surgical weight loss surgeries in common use: gastrointestinal bypass surgery, which is commonly performed in the form of a Roux-en-Y, i.e., a small portion of the stomach (less than a quarter) is left to anastomose directly to the small intestine in a Y-shape. Sleeve-like gastrectomy, in which most of the stomach is removed, leaving only a small part of the stomach in the shape of a sleeve. Second, the study introduction: the study by the United States five medical centers enrolled 242 severely obese adolescent patients, its average body mass index BMI up to 53kg/m2, the average age of 17 ± 1.6 years. The patients were divided into two groups, one with a Roux-en-Y gastric bypass, with 161 patients, and the other with a sleeve gastrectomy, with 67 patients. Patients in both groups were followed up for 3 years after surgery. The results showed an average weight loss of 27%, 28% in the gastric bypass group and 26% in the sleeve gastrectomy group. 95% of patients with type 2 diabetes mellitus at baseline were cured. 86% of patients with renal abnormalities recovered. 76% of patients with pre-diabetes mellitus returned to normal. 74% of patients with high blood pressure were controlled. 66% of patients with dyslipidemia returned to normal. However, the surgery, after all, affected the intestinal absorption of trace elements and vitamins, so 57% of the patients had hypoferritinemia, indicating that the patients had iron deficiency and were prone to iron deficiency anemia. In addition, 13% of the patients needed another intra-abdominal surgery. This indicates that after surgery patients should be followed up by an endocrinologist with appropriate micronutrient and vitamin supplements. Monitoring of iron metabolism in the body and regular checking of anemia indicators.