1. Factors that Reduce the Risk of Rebound Weight Gain ( 減低體重反彈的要素 ) Centre for Nutritional Studies School of Public Health The Chinese University of Hong Kong

2. Background 背景 Classification (BMI) Year 2004Year 2005Year 2006Year 2007Year 2008 Underweight 過輕 (BMI < 18.5) 10.2%9.6%9.2%10.3%9.5% Normal 標準 (BMI 18.5 - <23.0) 50.9%47.2%45.6%45.5%46.9% Overweight 過重 (BMI 23.0 - <25.0) 16.8%18.8%17.6%16.9%17.1% Obese 肥胖 (BMI=or>25.0) 21.6%20.7%23.4%21.6%22.2% Unknown/ Missing/Outliers 不明 0.6%3.7%4.2%5.7%4.3% Department of Health

3. Year 2004 Year 2005 Year 2006 Year 2007 Year 2008 17.2%15.4%15.5%16.6%17.4% Percentage of population who tried to lose weight during the past 12 months 過去 12 個月，嘗試進行減肥的人士有 : Department of Health Male 男性 ~ 14.x – 15. x % Female 女性 ~ 17.x – 20.x %

4. Design of survey 調查方法 : Random calls for phone interviews from a list of finished weight loss cases (for at least 4% weight loss) at the Centre in the past 6 years (n=5049) 利用電話訪問過去 6 年在本中心完成體重管理課程之病人 Period of Survey 訪問時期 : 2008-2009 Target calls 訪問目標人數 : 1000 Successful reached calls 成功訪問人數 : 602

5. Demography of the subjects 被訪者背景 N( 人數 ) = 602 Female:male ( 女性 : 男性 ) = 454:148 Mean age ( 平均年齡 ) = 42.7 ± 11.6 Mean BMI ( 平均身高體重指標 ) = 28.4 ± 4.4 kg/m 2 Mean lost weight ( 平均減去磅數 ) = 16.2% ± 4.0 of initial weight (4.3-34.9%) Mean weight loss duration ( 平均減肥時間 ) = 3.6 months (1.5 – 15 months) Mean rate loss ( 平均減肥速度 ) = 4.1 ± 2.2 lbs/mth (3.7-10 lbs/mth)

6. Year after weight loss 維持期 ( 年 ) No of subjects ( 人數 ) 140 2136 3277 4118 ≥531 年人數 Distribution of subjects in 1-6 year of maintenance ( 1-6 年維持期的人數分佈 ) :

7. Years after weight loss( 減肥後至今的年數 ) % of rebound weight gain ( 體重 回升 百份 比 ) 1 year 2 year 3 year 4 year 5 year Total <0 22.5% (9) 11.8% (16) 11.9% (33) 10.2% (12) 9.7% (3) 12.1% (73) 0-25% 60.0% (24) 64.0% (87) 46.9% (130) 38.1% (45) 29.0% (9) 49.0% (295) 26-50% 15.0% (6) 14.0% (19) 15.2% (42) 20.3% (24) 25.8% (8) 16.4% (99) 51-75% 2.5% (1) 6.6% (9) 16.2% (45) 19.5% (23) 22.6% (7) 14.1% (85) 76-100%0 3.7% (5) 7.2% (20) 10.2% (12) 9.7% (3) 6.6% (40) >100%00 2.5% (7) 1.7% (2) 3.2% (1) 1.7% (10) 百份比 Percentage of weight regained after weight loss 體重回升百份比 Mean maintenance period ( 平均維持期 ) = 2.7± 0.9years Mean weight regained of lost weight ( 平均回升體重 ) = 16.8 ± 5.9 %

8. % of rebound weight gain ( 體重回升百份比 ) 回升體重 體重 x 100%) = weight regained during the weight maintenance period ÷ total weight loss during the weight reduction period x 100% ( 回升體重 ÷ 減去體重 x 100%) e.g. Mr A lost 20 kg and then regained 5kg after 3 years, his % of rebound weight gain = 5kg ÷ 20kg x100% = 25%

9. Weight change of subjects treated by Orlistat ( 服用賽尼可後的體重改變 ) -6 -4 -2 0 Mean percentage change of body weight (%) 6 months Orlistat treatment 6 months maintenance % of rebound weight gain ~ 77% after 6 months of drug cessation

10. Double-blind, randomized clinical trial of orlistat versus placebo with a rerandomization of participants after the 1st year. Reprinted from The Lancet, vol. 352, Sjostrom et al., "Randomized Placebo-Controlled Trial of Orlistat for Weight Loss and Prevention of Weight Regain in Obese Patients: European Multicenter Orlistat Study Group," pp 167–172, copyright 1998 % of rebound weight gain ~ 43% after 1 year of drug cessation

11. Six-month randomized, placebo-controlled dose-ranging trial with sibutramine at six doses and placebo. Reproduced from Bray et al. (1999) % of rebound weight gain ~ 21- 44% after 6 weeks of drug cessation

12. Adapted from James et al. (2000). % of rebound weight gain ~74% after 1.5 years of drug cessation

13. Effect on body weight of rimonabant in a 2-year, randomized, placebo- controlled clinical trial. Adapted from The Journal of the American Medical Association, volume 295, pp 761–775. Copyright © 2006 % of rebound weight gain ~ 71% after 1 year of drug cessation

14. Long-term weight regain after gastric bypass: a 5-year prospective study. ( 胃繞道手術後之長期體重回復 : 長達 5 年的研究 ) Obesity Surgery. 18(6):648-51, 2008 Jun. BACKGROUND: A certain weight gain occurs after obesity surgery compared to the lower weight usually observed between 18 and 24 months postsurgery. The objective of this study was to evaluate weight regain in patients submitted to gastric bypass over a 5-year follow-up period. MATERIALS AND METHODS: A longitudinal prospective study was conducted on 782 obese patients of both genders. Only patients with at least 2 years of surgery were included. The percentage of excess body mass index (BMI) loss at 24, 36, 48, and 60 months postsurgery was compared to the measurements obtained at 18 months after surgery. Surgical therapeutic failure was also evaluated. RESULTS: Percent excess BMI loss was significant up to 18 months postsurgery (p < 0.001), with a mean difference in BMI of 1.06 kg/m2 compared to 12 months postsurgery. Percent BMI loss was no longer significant after 24 months, and weight regain became significant within 48 months after surgery (p < 0.01). Among the patients who presented weight regain, a mean 8% increase was observed within 60 months compared to the lowest weight obtained at 18 months after surgery. The percentage of surgical failure was higher in the superobese group at all times studied, reaching 18.8% at 48 months after surgery. CONCLUSION: Weight regain was observed within 24 months after surgery in approximately 50% of patients.( 約 五成經過胃繞道手術後之人士在 24 個月內錄得體重回復 ) Both weight regain and surgical failure were higher in the superobese group. Studies in regard to metabolic and hormonal mechanisms underlying weight regain might elucidate the causes of this finding.

15. Intragastric balloon for treating obese people ( 以內置胃水球治療過肥人士 ) CUHK 2008 For patients treated with intragastric balloon, the balloon was removed at 6 months. Of these 122 patients, 28% (34 patients) finally went on for definitive surgical treatment. Among the 88 patients who were treated with BIB alone, we observed a mean weight loss of about 10kg at 6 months and the diabetes control had improved in about 40% of patients. However, upon further follow up at 18 months, only about 30% of patients maintained their weight loss for more than 10% of their initial weight. Weight rebound occurred to the remaining 70%. ( 在 跟進一年半後，當中只有約三成病人能夠 持續地減少一成的原本體重，其餘七成病 人體重則出現反彈。 )

16. Obesity surgery results depending on technique performed: long-term outcome. ( 肥胖手術結果 取決於執行之技術 : 一個長期結果 ) Obesity Surgery. 19(4):432-8, 2009 Apr. BACKGROUND: Many techniques have excellent results at 2 years of follow-up but some matters regarding their long-term efficacy have arisen. This is why bariatric surgery results must be analyzed in long-term follow-up. The aim of this study was to extend the analysis over 5 years, evaluating weight loss, morbidity, and mortality of the surgical procedures performed. METHODS: This was a retrospective cohort study of the different procedures for morbid obesity practiced in our Department of Surgery for morbid obesity. The results have been analyzed in terms of weight loss, morbidity improvement, and postoperative morbidity (Bariatric Analysis And Reporting Outcome System). RESULTS: One hundred twenty-five patients were operated on open vertical banded gastroplasty (VBG), 150 patients of open biliopancreatic diversion (BPD) of Scopinaro, 100 patients of open modified BPD (common limb 75 cm; alimentary limb 225 cm), and 115 patients of laparoscopic Roux-en-Y gastric bypass (LRYGBP). Mean follow-up was: VBG 12 years, BPD 7 years, and LRYGBP 4 years. An excellent initial weight loss was observed at the end of the second year of follow-up in all techniques, but from this time an important regain of weight was observed in VBG group and a discrete weight regain in LRYGBP group. Only BPD groups kept excellent weight results so far in time. Mortality was: VBG 1.6%, BPD 1.2%, and LRYGBP 0%. Early postoperative complications were: VBG 25%, BPD 20.4%, and LRYGBP 20%. Late postoperative morbidity was: protein malnutrition 11% in Scopinaro BPD, 3% in Modified BPD group, and no cases reported either in VBG group or LRYGBP group; iron deficiency 20% VBG, 62% Scopinaro BPD, 40% modified BPD, and 30.5% LRYGBP. A 14.5% of VBG group required revision surgery to gastric bypass or to BPD due to 100% weight regain(14.5% 已接受胃垂直束帶造形術組別因完全的體重反彈 需接受修正手術至胃繞道手術或膽胰分流術 ) or vomiting. A 3.2% of Scopinaro BPD with severe protein malnutrition required revision surgery to lengthen common limb to 100 cm. A 0.8% of LRYGBP required revision surgery to distal LRYGBP (common limb 75 cm) due to 100% weight regain. CONCLUSIONS: The most complex bariatric procedures increase the effectiveness but unfortunately they also increase morbidity and mortality. LRYGBP is safe and effective for the treatment of morbid obesity. Modified BPD (75-225 cm) can be considered for the treatment of superobesity (body mass index > 50 kg/m(2)), and restrictive procedures such as VBG should only be performed in well-selected patients due to high rates of failure in long-term follow-up.

17. % of “Weight maintainers” (weight regain <25%) ( 能維持體重 人士百分比 -- 體重回升 <25% ) % of “Weight regainers” (weight regain >50%) ( 能維持體重 人士百分比 -- 體重回升 >50% ) Significance ( 重要性 ) ( 重要性 ) Regular self-weighing ( 定期自我量 重 ) 82.343.0P<0.001 Follow food quota ( 限制食物配額 ) 75.328.9P<0.001 Keep food diary ( 食物日誌 ) 63.022.2P<0.001 Late dinner ( 遲吃晚餐 ) 37.046.7P<0.05 Change job nature (environment) ( 工作性則 / 環境轉變 ) 4.924.4P<0.001 Pressure ( 壓力 ) 73.173.3NS No professional support ( 專業人士 支持 ) 20.983.0P<0.001 Factors contributes to rebound weight gain ( 導致體重反彈的因素 )

18. % of “Weight maintainers” (weight regain <25%) ( 能維持體重 人士百分比 -- 體重回升 <25%) % of “Weight regainers” (weight regain >50%) ( 能維持體 重人士百分比 -- 體重 回升 > 50%) Significance ( 重要性 ) ( 重要性 ) Weight loss >8lbs/mth ( 減重 多於 8lbs/ 月 ) 2.220.7P<0.001 No Ex during weight loss period ( 於減重期間運動次數 ) 19.048.1P<0.02 Stop or drastic reduce exercise after weight loss ( 於 減重後停止或極端的減少運 動 ) 26.971.9P<0.001 Others (menopause, diseases, pregnancy, etc.) ( 其他 : 如更年 期, 疾病, 懷孕 ) 3.35.2NS Factors contributes to rebound weight gain (con’t) ( 不同的因素導致體重反彈 ) ( 續 )

19. Prevent weight regain (3%) ( 避免體重回升 ) American College of Sports Medicine American College of Sports Medicine –>250 min/wk physical activity (>250 分鐘 / 星期 的運動 ) –~60 min walk/day at moderate intensity ( 每天約 60 分鐘步行 中 等速度 ) The Journal of the American Medical Association The Journal of the American Medical Association –V little wt regain ( 好少體重回升 ) >200 min/wk moderate-intensity PA (200 分鐘 / 星期 中等速度 ) >200 min/wk moderate-intensity PA (200 分鐘 / 星期 中等速度 ) –10% wt loss at 24 mon ( 於 24 月有一成減重 ) 275 min/wk (1500 kcal/wk) PA (275 分鐘 / 星期 1500kcal/ 星期 ) 275 min/wk (1500 kcal/wk) PA (275 分鐘 / 星期 1500kcal/ 星期 ) More is better ( 更多的為更好 ) More is better ( 更多的為更好 )

20. Diet & ex ( 運動與飲食 ) International Journal of Obesity International Journal of Obesity –20% greater weight loss in diet + ex prog ( 在 節食和持續運動後有多於 20% 體重減少 ) –20% greater sustained weight loss after 1 yr ( 一年後有多於 20% 持續的 體重減少 ) Increase wt loss with diet restriction ( 飲食 限制下有體重增加 ) Increase wt loss with diet restriction ( 飲食 限制下有體重增加 ) –But not with severe diet restriction ( 沒有嚴重 的 飲食限制 )

21. Moderate intensity PA ( 中等強度的運動 ) Brisk walking ( 輕快的步行 ) Brisk walking ( 輕快的步行 ) Biking ( 踏單車 ) Biking ( 踏單車 ) Swimming ( 游泳 ) Swimming ( 游泳 ) Double tennis ( 雙打網球 ) Double tennis ( 雙打網球 ) 3-5.9 METS (3-5.9 代謝當量時間單位 ) 3-5.9 METS (3-5.9 代謝當量時間單位 )

22. Year after weight loss ( 減重後的年數 ) % of rebound weight gain ( 體重回升百分 比 ) 1 year 2 year 3 year Total <0 11.8% (4) 16.7% (5) 14.3% (3) 14.3% (12) 0-25% 88.2% (30) 88.2% (30) 83.3% (25) 85.7% (18) 85.7% (72) 26-50%0000 51-75%0000 76-100%0000 >100%0000 升 Percentage of weight regained after weight loss for those regular visits ( 減重後維持定期隨訪人士的 體重回升百分比率 )

23. Conclusion ( 結論 ) 1.The challenge for obesity treatment is not only losing weight but keeping it off. ( 減肥治療的挑戰 不止是 減輕體重, 還有維持體重。 ) 2.The permanent weight loss maintenance may require lifelong healthy lifestyle. ( 長久減重的維持在於一 輩子的健康生活習慣。 ) 3.Regular weighing and professional monitoring can help people to stay healthy weight. ( 定期的量重和 專業人員的幫助有助我們維持健康的體重 )

24. Case 1 ( 個案一 ) 1 st Initial 1 st Final 2 nd Initial (15 months after the 1 st weight loss) 2 nd Final 18 months after weight loss Body weight (kg) ( 體重 ) 63.256.259.753.553.4 BMI (kg/m 2 ) ( 體質指數 ) 25.622.724.221.621.6 Body Fat (%) ( 身體脂肪百 分比 ) 36.429.633.228.127.3 Exercise habits ( 運動 習慣 ) NoneNoneNone 1-4/week @30- 60min 1-2/week @30- 60min *regular visit after 2 nd weight loss

25. Case 2 ( 個案二 ) InitialFinal 15 months after weight loss Body weight (kg) ( 體重 ) 73.959.058.6 BMI (kg/m 2 ) ( 體質指數 ) 27.421.921.7 Body Fat (%) ( 身體脂肪百分比 ) ( 身體脂肪百分比 )39.127.527.9 Exercise habits ( 運動習慣 ) 1-2 hour /day 40min – 1.5 hour/day 1-1.5 hour x 4- 5/week *regular visit after weight loss

26. InitialFinal 5 years after the weight loss* 3 months ago ** Present Body weight (kg) ( 體重 ) 70.551.350.555.352.8 BMI (kg/m 2 ) ( 體質指數 ) 33.524.424.026.325.1 Body Fat (%) ( 身體脂肪百分 比 ) 46.927.628.832.030.2 Exercise habits ( 運動 習慣 ) None 0.5-1 hr/week None ** Menopause, disease and changed working time *regular visit after weight loss Case 3 ( 個案三 )