BACKGROUND: Percentage alterable weight loss (AWL) is the only known weight loss metric independent of the initial body mass index (BMI), a unique feature ideal for use in weight loss research. AWL was not yet validated. The aim of the study is to validate the AWL metric and to confirm advantages over the excess weight loss (EWL) metric. METHODS: AWL is tested with 2-year weight loss results of all primary laparoscopic Roux-en-Y gastric bypass patients operated in our hospital. Nadir results of patients with higher and lower initial BMI are compared (Mann-Whitney; p < 0.05) using outcome metrics BMI, percentage weight loss (WL), EWL, and AWL, for the whole group, for each gender, and for <40 and ≥40 years separately. RESULTS: Five-hundred patients (401 female) out of 508 (98.4 %) had 2-year follow-up. Of all four metrics, only AWL rendered results not significantly influenced by initial BMI. The AWL outcome is initial BMI independent for both genders and age-groups. Results also confirm that women and younger patients had significantly higher AWL outcome. CONCLUSION: The recently developed AWL metric, defined as 100% × (initialBMI - BMI) / (initialBMI - 13), is now validated. In contrast to the well-known outcome metrics BMI, EWL, and WL, the AWL metric is independent of the initial BMI. It should replace the misleading EWL metric for comparing weight loss results in bariatric research and for expressing the effectiveness of bariatric procedures. This effectiveness does not act on the total body mass, or on the excess part, but on the alterable part, defined as BMI minus 13 kg/m(2) for all adult patients, female, male, young, and old.
BACKGROUND: Percentage alterable weight loss (AWL) is the only known weight loss metric independent of the initial body mass index (BMI), a unique feature ideal for use in weight loss research. AWL was not yet validated. The aim of the study is to validate the AWL metric and to confirm advantages over the excess weight loss (EWL) metric. METHODS: AWL is tested with 2-year weight loss results of all primary laparoscopic Roux-en-Y gastric bypass patients operated in our hospital. Nadir results of patients with higher and lower initial BMI are compared (Mann-Whitney; p < 0.05) using outcome metrics BMI, percentage weight loss (WL), EWL, and AWL, for the whole group, for each gender, and for <40 and ≥40 years separately. RESULTS: Five-hundred patients (401 female) out of 508 (98.4 %) had 2-year follow-up. Of all four metrics, only AWL rendered results not significantly influenced by initial BMI. The AWL outcome is initial BMI independent for both genders and age-groups. Results also confirm that women and younger patients had significantly higher AWL outcome. CONCLUSION: The recently developed AWL metric, defined as 100% × (initialBMI - BMI) / (initialBMI - 13), is now validated. In contrast to the well-known outcome metrics BMI, EWL, and WL, the AWL metric is independent of the initial BMI. It should replace the misleading EWL metric for comparing weight loss results in bariatric research and for expressing the effectiveness of bariatric procedures. This effectiveness does not act on the total body mass, or on the excess part, but on the alterable part, defined as BMI minus 13 kg/m(2) for all adult patients, female, male, young, and old.
Authors: Arnold W van de Laar; Marije H Dollé; L Maurits de Brauw; Sjoerd C Bruin; Yair I Acherman Journal: Obes Surg Date: 2015-04 Impact factor: 4.129
Authors: Marc Beisani; Fàtima Sabench Pereferrer; Ramón Vilallonga; Óscar González López; Alicia Molina López; Daniel Del Castillo Dejardin; Amador García Ruiz de Gordejuela; José Manuel Fort López-Barajas; Manel Armengol Carrasco Journal: Obes Surg Date: 2021-01-04 Impact factor: 4.129
Authors: Anne-Sophie van Rijswijk; Nienke van Olst; Winnie Schats; Donald L van der Peet; Arnold W van de Laar Journal: Obes Surg Date: 2021-05-17 Impact factor: 4.129