Introduc)on • Weight loss and preven1ng weight gain are major concerns for many people across the world; • A be;er understanding of how most weight loss eﬀorts are made, by whom, through what means, and how successful they are, provides cri1cal knowledge to inform public health prac1ces. Study protocol: PROSPERO 2014:CRD42014010572 Prevalence and correlates of non‐surgical weight control a7empts in adults: a systema)c review and meta‐analysis Inês Santos 1* , Eliana V. Carraça 1 , Marta Marques 1 , Falko Snieho7a 2 , Pedro J. Teixeira 1 1 CIPER, Faculty of Human Kine)cs, University of Lisbon 2 CTRPH, Ins)tute of Health and Society, Medical Faculty, Newcastle University This study was funded by NaDonal Funding through the Portuguese Science and Technology FoundaDon (SFRH/BD/80739/2011 to Inês Santos). 14 th Annual Meeting of the ISBNPA, June 3-6 2015 Edinburgh, Scotland Eligibility criteria Search strategy • Comprehensive search in three electronic databases: PubMed, PsycInfo and Web of Science; • Combina1ons of the following terms: weight control, weight loss, diet, a;empts, prevalence, correlates, strategies, prac1ces, determinants, and reasons; • No restric1ons regarding language of publica1on. Purpose Summarize the available epidemiological data on the prevalence of weight loss and maintenance a7empts among adults and iden)fy correlates, speciﬁc strategies used and reasons behind those a7empts. Conclusions • Epidemiological/observa1onal studies; • Subjects aged 18 years and older; • Report current weight control a;empts (i.e., trying to lose or maintain weight within the 12 months preceding the survey). • Exclusion criteria: ethnic minori1es, pregnant women, athletes, and popula1ons with physical or mental disorders. Forest plot: Prevalence of weight loss aSempts  Studies design: cross‐sec1onal (n=48) and prospec1ve cohort (n=5);  Type of surveys: in‐person (n=26), mail (n=11), online (n=2) and telephone (n=14);  Surveys dates: 1975‐2012;  Popula1on: na1onally representa1ve (n=33), regionally representa1ve (n=9) and speciﬁc/ non‐representa1ve (n=14);  General popula1on (n=44) and overweight/obese samples (n=9) *isantos@fmh.ulisboa.pt METHODS Data extraction, methodological quality and analysis • The Joanna Briggs Ins/tute data extrac/on form for prevalence and incidence studies; • The Joanna Briggs Ins/tute cri/cal appraisal checklist for studies repor/ng prevalence data; • Conducted by the ﬁrst two authors • Combined prevalence es1mates of weight control a;empts calculated with Comprehensive Meta‐Analysis so]ware (CMA2). Crawford et al, 1998 Australia reg. 1342 0,204 0,183 0,226 Timperio et al, 2000 Australia reg. 900 0,229 0,203 0,258 Jeffery et al, 2013 Australia reg. 1634 0,391 0,368 0,415 Charles et al, 2006 Australia spec. 1973 0,370 0,349 0,392 Yoong et al, 2012 Australia spec. 1335 0,500 0,473 0,527 Paxton et al, 1994 Australia spec. 994 0,469 0,438 0,500 Machado et al, 2012 Brazil reg. 2732 0,266 0,250 0,283 Green et al, 1997 Canada nat. 17564 0,326 0,319 0,333 Korkeila et al, 1999 Finland nat. 7729 0,186 0,177 0,195 Monneuse et al, 1997 France spec. 656 0,238 0,207 0,272 Jackson et al, 2013 Great Britain nat. 810 0,450 0,416 0,484 Wakui et al, 2002 Japan spec. 146 0,322 0,251 0,402 Mardiah et al, 2012 Malaysia spec. 233 0,738 0,678 0,790 Kong et al, 2002 Malaysia spec. 1032 0,245 0,220 0,272 Mendez-Hernandez et al, 2010 Mexico spec. 2651 0,388 0,370 0,407 Leong et al, 2013 New Zealand nat. 1601 0,394 0,370 0,418 Hjartaker et al, 2001 Norway nat. 10025 0,516 0,506 0,526 Santos et al, 2015 Portugal nat. 1098 0,243 0,219 0,269 Stephenson et al, 1987 USA nat. 170971 0,350 0,348 0,352 Serdula et al, 1995(1) USA nat. 117827 0,386 0,383 0,389 Williamson et al, 1992 USA nat. 64637 0,335 0,331 0,339 Serdula et al, 1995(2) USA nat. 114025 0,337 0,334 0,340 Horm et al, 1993 USA nat. 31347 0,317 0,312 0,322 Levy et al, 1993 USA nat. 7805 0,193 0,184 0,202 Serdula et al, 1999 USA nat. 107804 0,364 0,361 0,367 Kruger et al, 2004 USA nat. 30433 0,309 0,304 0,314 Bish et al, 2005 USA nat. 164187 0,395 0,393 0,397 Wee et al, 2001 USA nat. 17317 0,300 0,293 0,307 Weiss et al, 2006 USA nat. 4354 0,409 0,394 0,424 Wharton et al, 2008 USA nat. 38204 0,498 0,493 0,503 Kimmons et al, 2006 USA nat. 3771 0,580 0,564 0,596 Yaemsiri et al, 2011 USA nat. 16720 0,370 0,363 0,377 Moten et al, 2014 USA nat. 7059 0,534 0,522 0,546 Lebrun et al, 2013 USA nat. 3949 0,601 0,586 0,616 Nguyen et al, 2015 USA nat. 3407 0,520 0,503 0,537 Reba-Harrelson et al, 2009 USA nat. 4023 0,672 0,657 0,686 Anderson et al, 2002 USA nat. 1760 0,648 0,625 0,670 Bish et al, 2007(a) USA nat. 5608 0,512 0,499 0,525 Nicklas et al, 2012 USA nat. 4021 0,630 0,615 0,645 Bish et al, 2007(b) USA nat. 111456 0,557 0,554 0,560 Duncan et al, 2011 USA nat. 4784 0,474 0,460 0,488 Post et al, 2011 USA nat. 5474 0,502 0,489 0,515 Barrett et al, 1995 USA reg. 2072 0,344 0,324 0,365 Riley et al, 1998 USA reg. 1143 0,099 0,083 0,118 Kabeer et al, 2001 USA reg. 3010 0,370 0,353 0,387 Thomas et al, 2002 USA reg. 1232 0,361 0,335 0,388 Jeffery et al, 1991 USA spec. 4647 0,197 0,186 0,209 Zapka et al, 2009 USA spec. 813 0,627 0,593 0,660 Rose et al, 2013 USA spec. 1510 0,510 0,485 0,535 Nothwehr et al, 2005 USA spec. 123 0,488 0,401 0,576 Kennen et al, 2005 USA spec. 210 0,498 0,431 0,565 Lee et al, 2007 USA spec. 414 0,730 0,685 0,771 0,404 0,380 0,428 0,00 0,50 1,00 Prevalence (95% CI) Studies Popula)on Sample size Prevalence 95% CI Characteristics of included studies (n=53) RESULTS 51 studies, I 2 = 99.8% Overall: 40.4%, p<0.001  13 studies reported weight maintenance a7empts ranging from 10.4% to 48.4% (overall: 26.9%, p<0.001; I 2 = 99.8%)  Main correlates: gender (mostly women) and BMI (higher);  Other correlates: age, ethnicity, marital status, educa1onal level, SES, smoking status, self‐percep1on of weight and health professional advice to lose weight;  Most frequently used strategies/prac)ces: ea)ng fewer calories, increase physical ac)vity, watch type of food eaten, reduce por)ons and reduce amount of fat;  Other strategies/prac1ces: avoid sugar, count calories, monitoring weight, a;ending a weight loss group/program, taking weight loss pills/supplements and laxa1ves/ diure1cs;  Most frequently reported reasons: improve wellbeing, appearance, improve self‐ esteem and improve general health;  Other reasons: health professional advice, improve ﬁtness condi1on, please spouse/ partner or family, improve social life and special event or season.  About 40% of individuals across studies (from 1975 to 2012) reported trying to lose weight. Key factors associated with weight control a;empts were iden1ﬁed.  Systema1cally summarizing relevant informa1on on weight loss a;empts can contribute to improve obesity preven1on and treatment, avoid psychological suﬀering associated with fruitless a;empts, and allocate public health resources more eﬃciently.