Successful-weight-loss-maintenance-A-systematic-review-of-weight-control-registries

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OB E S I T Y /WE I G H T L O S S MA I N T E N ANC E
Successful weight loss maintenance: A systematic review of
weight control registries
Catarina Paix~ao1 | Carlos M. Dias2,3 | Rui Jorge4,5 | Eliana V. Carraça1 |
Mary Yannakoulia6 | Martina de Zwaan7 | Sirpa Soini8 | James O. Hill9 |
Pedro J. Teixeira1 | Inês Santos1,10
1Centro Interdisciplinar para o Estudo da
Performance Humana, Faculdade de
Motricidade Humana, Universidade de Lisboa,
Cruz Quebrada Dafundo, Portugal
2Centro de Investigaç~ao em Saúde Pública
(CISP), NOVA-Escola Nacional de Saúde
Pública, Lisbon, Portugal
3Departamento de Epidemiologia, Instituto
Nacional de Saúde Doutor Ricardo Jorge,
Lisbon, Portugal
4Centro de Investigaç~ao Interdisciplinar Egas
Moniz (CiiEM), Instituto Universitário Egas
Moniz, Almada, Portugal
5Unidade de Investigaç~ao do Instituto
Politécnico de Santarém, Escola Superior
Agrária, Instituto Politécnico de Santarém,
Santarém, Portugal
6Department of Nutrition and Dietetics,
Harokopio University, Athens, Greece
7Department of Psychosomatic Medicine and
Psychotherapy, Hannover Medical School,
Hannover, Germany
8Department of General Practice and Primary
Health Care, University of Helsinki, Helsinki,
Finland
9Department of Nutrition Sciences, University
of Alabama at Birmingham, Birmingham, Alabama
10Laboratório de Nutriç~ao, Faculdade de
Medicina, Universidade de Lisboa, Lisbon,
Portugal
Correspondence
Inês Santos, Centro Interdisciplinar para o
Estudo da Performance Humana, Faculdade de
Motricidade Humana, Universidade de Lisboa,
Estrada da Costa, Cruz Quebrada 1495-688,
Portugal.
Email: isantos@fmh.ulisboa.pt
Funding information
Foundation for Science and Technology
Portugal, Grant/Award Number:
PTDC/DES/72317/2006, 2008-2011
Summary
Weight loss maintenance is a major challenge for obesity treatment. Weight control
registries can be useful in identifying psychological and behavioural factors that could
contribute to better long-term success. The objective of this study is to describe the
existing weight control registries and their participants and identify correlates of
weight loss maintenance. A comprehensive search of peer-reviewed articles publi-
shed until November 2018 was conducted in PubMed, Web of Science, and Scopus.
Studies that reported results from weight control registries were considered. Fifty-
two articles, corresponding to five registries (the United States, Portugal, Germany,
Finland, and Greece), were included. Registries differed in inclusion criteria and
procedures. Of 51 identified weight loss and maintenance strategies, grouped in
14 domains of the Oxford Food and Activity Behaviors taxonomy, the following were
the most frequently reported: having healthy foods available at home, regular break-
fast intake, increasing vegetable consumption, decreasing sugary and fatty foods, lim-
iting certain foods, and reducing fat in meals. Increased physical activity was the
most consistent positive correlate of weight loss maintenance. To our knowledge,
this is the first systematic review of information about successful weight loss mainte-
nance obtained from weight control registries. Key common influential characteristics
of success were identified, which can inform future prospective studies and weight
management initiatives.
K E YWORD S
behaviours, correlates, weight loss maintenance
Abbreviations: WL, weight loss; WLM, weight loss maintenance.
Received: 20 December 2019 Revised: 9 January 2020 Accepted: 10 January 2020
DOI: 10.1111/obr.13003
Obesity Reviews. 2020;1–15. wileyonlinelibrary.com/journal/obr © 2020 World Obesity Federation 1
https://orcid.org/0000-0002-0531-2412
https://orcid.org/0000-0002-0206-5874
https://orcid.org/0000-0002-5261-2688
https://orcid.org/0000-0002-5789-811X
https://orcid.org/0000-0003-2171-7337
https://orcid.org/0000-0002-7918-6957
https://orcid.org/0000-0001-6190-1177
https://orcid.org/0000-0003-4690-2264
https://orcid.org/0000-0001-7202-0527
https://orcid.org/0000-0002-1638-8551
mailto:isantos@fmh.ulisboa.pt
https://doi.org/10.1111/obr.13003
http://wileyonlinelibrary.com/journal/obr
1 | INTRODUCTION
Preventing weight regain after weight loss (WL) remains the biggest
challenge in obesity treatment. Behavioural interventions that address
diet and physical activity are moderately effective in the short term,
but most individuals experience significant weight regain (returning to
baseline values) in the long term.1 However, successful weight loss
maintenance (WLM) is critical to uphold health benefits.2 Therefore, a
deeper understanding of the factors that can facilitate long-term
WLM is needed in order to provide (the high number of) individuals
actively trying to lose weight3 with proven solutions/strategies for
lifelong weight management.
The US National Weight Control Registry pioneered the study of
successful WLM, identifying several psychological and behavioural
characteristics of individuals who achieved long-term success.4,5 Sub-
sequently, weight control registries were developed in several other
countries, with the same goal of studying successful maintenance of
WL (eg, previous studies6-9).
The process of WLM involves complex interactions among
behavioural, physiological, environmental, and cognitive/psychosocial
factors.10 It is well known that WLM relies on permanent adjustments
between energy intake-reducing behaviours and energy expenditure-
increasing behaviours.11 How that is achieved is poorly understood.
Some psychological determinants such as self-efficacy (ie, for moni-
toring one's weight and eating behaviour),11-13 autonomous motiva-
tion, and a positive body image14 appear to impact behaviour change,
but our understanding of the psychological, social, physical, and envi-
ronmental determinants of WLM is incomplete.11,15 Weight control
registries, where successful individuals are studied, are tools that may
be helpful in better understanding the factors that impact long-term
WLM, and they have not been systematically evaluated so far.
This systematic review aimed to (a) identify and describe existing
weight control registries (eg, regarding inclusion/exclusion criteria,
recruitment procedures, and assessments and instruments used);
(b) describe the sociodemographic, cognitive, and behavioural charac-
teristics of their participants (ie, individuals who successfully achieved
long-term WLM); and (c) synthesize the sociodemographic, behav-
ioural, and psychological correlates of WLM magnitude.
2 | METHODS
This systematic review is reported in accordance with MOOSE Guide-
lines (Meta-analysis of Observational Studies in Epidemiology).16 Key
methodological features of this review were specified in advance and
documented in a protocol (PROSPERO International Prospective Reg-
ister of Systematic Reviews: registration number CRD42019129637).
2.1 | Eligibility criteria
Studies were selected for this review if they included data obtained
from existing weight control registries. Review, perspective, and
commentary articles were not included, nor articles written in lan-
guages other than English and Portuguese.
2.2 | Search strategy and study selection
A comprehensive search of peer-reviewed articles (published up to
November 2018 or ahead of print) was conducted in three electronic
databases: PubMed, Web of Science, and Scopus. Searches included
combinations of the following terms: “weight loss maintenance”,
“weight control registry”, “national weight control registry”, Portu-
guese, Greek, Finnish, and German. The full search strategy is
available from the authors upon request. Additionally, manual cross-
referencing of retrieved articles and hand searches of key scientific
journals and the registries websites were performed.
Two authors (C.P. and I.S.) screened titles and abstracts of poten-
tially eligible studies. Duplicate entries were removed. Relevant arti-
cles were then retrieved for a full-text review. The sametwo
researchers independently reviewed the full text of potential studies.
Discrepancies were resolved by consensus. Endnote X7 for Mac OS X
was used for reference managing.
2.3 | Quality assessment
The methodological quality of included studies was assessed using
an adapted version of the Quality Assessment Tool For Quantita-
tive Studies developed by the Effective Public Health Practice Pro-
ject17 and recommended for use by the Cochrane Public Health
Review Group.18 This tool was previously used in other systematic
reviews including observational studies (eg, previous studies14,19). It
addresses seven key domains: (a) study design, (b) selection bias,
(c) withdrawals and dropouts, (d) confounders, (e) data collection,
(f) data analysis, and (g) reporting. Each domain was classified as
strong, moderate, or weak, and a global rating was determined.
Two of four researchers (C.P., I.S., R.J., and E.V.C.) independently
rated each of the seven domains and overall quality of each study.
Disagreements were resolved by consensus. Interrater agreement
across categories was adequate (Cohen κ = .61).20
2.4 | Data extraction
A data extraction form was developed to compile information
about (a) the weight control registries that included designation,
country of origin, year of implementation, sample size, recruitment
procedure, period of recruitment, inclusion and exclusion criteria,
assessments, and instruments used; (b) the participants—specifically,
their sociodemographic characteristics (eg, sex, age, ethnicity, edu-
cational level, employment, and marital status), weight history (life-
time maximum weight and body mass index [BMI; kg m−2],
baseline weight and BMI, WL [kg] and period of WLM at registry
entry, and weight stability at follow-up), and the cognitive and
2 PAIX~aO ET AL.
TABLE 1 Weight control registries' and participants' characteristics
National Weight
Control Registry
(NWCR)4,5,21-51
Portuguese Weight
Control Registry
(PWCR)6,52-54
German Weight
Control Registry
(GWCR)8,55-58
Finnish Weight
Control Registry
(FWCR)7,59-61 MedWeight62-67
Country
Designation United States Portugal Germany Finland Greece
Weight control registries' characteristics
Number of
published
articles
33 4 5 4 6
Year of
implementation
1993 2008 2009 2012 2012
Participants' sociodemographic characteristicsa
Maximum sample
size reported
532041,b 38853,c 4948 1587 52862,d
Sex (% female) 75.0 63.4 60.7 63.3 61.0
Age (y) 47.0 ± 12.2 39.0 ± 11.1 47.6 ± 12.7 44.5 ± 11.0 Maintainers: 29
(24-38)
Regainers: 37 (29-45)
Ethnicity (%
white)
95.0 - - - -
Education (%
higher)
85.0 (college) 69.1 (university
degree)
46.8 (academic
degree) (n = 492)
22.8 (>14 y of school) 16.0 ± 3.0 y of school
(n = 411)65
Employment (%
employed)
74.0 (n = 1422)23 78.7 (n = 198)6 76.9 (n = 489) 76.6 Maintainers: 52
(n = 289)
Regainers: 62
(n = 122)65
Marital status
(%
married/union)
67.9 (n = 3683)4 54.6 81.6 (n = 490) 72.8 Maintainers: 20
(n = 289)
Regainers: 43
(n = 122)65
Participants' weight historya
Lifetime
maximum
weight (kg)
103.8 ± 25.9
(n = 3683)4
92.5 ± 20.4 (n = 225) - - 90.0 (80.0-105.0)
(n = 239)67
Lifetime
maximum BMI
(kg m−2)
36.3 ± 8.1 (n = 3683)4 33.1 ± 6.4 (n = 225) 33.2 ± 6.5 35.9 (range 29.2-64.8) Maintainers: 33.1
± 6.9
Regainers: 32.4 ± 5.2
(n = 411)65
Weight at
baseline (kg)
71.5 ± 15.9
(n = 3683)4
74.1 ± 13.4 (n = 225) - - 78.1 ± 16.5
(n = 239)67
BMI at baseline
(kg m−2)
25.1 ± 4.5 26.6 ± 4.2 (n = 225) 25.7 ± 4.2 26.1 (range 17.3-41.2) Maintainers: 25.0
(22.8-28.1)
Regainers: 30.1
(27.6-34.3)
Weight loss at
baseline (kg)
32.3 ± 16.7
(n = 3683)4
18.3 ± 12.5 (n = 225) - 32.4 (range 9-81) Maintainers: 25.6
± 15.8
Regainers: 14.5 ± 4.5
(n = 226)63
(Continues)
PAIX~aO ET AL. 3
behavioural weight control strategies used; and (c) the
sociodemographic, behavioural, and psychological correlates of
the magnitude of WLM. Two of four researchers (C.P., I.S., R.J.,
and E.V.C.) independently extracted the data.
2.5 | Data synthesis
Registries' characteristics and participants' sociodemographic
characteristics, as well as the cognitive and behavioural strategies
they used for weight management, were qualitatively synthetized
and presented in tabular form (Tables 1 and 2, respectively). When
the same characteristic or strategy was reported in several
articles from the same registry, the one with a larger sample was used.
The prevalence of each strategy was estimated by combining data
derived from the largest sample size reported in each registry. Weight
management strategies were independently classified within
the domains of the Oxford Food and Activity Behaviors (OxFAB)
taxonomy68 by two of four researchers (C.P., I.S., R.J., and E.V.C.).
Discrepancies were resolved by consensus. This taxonomy was
TABLE 1 (Continued)
National Weight
Control Registry
(NWCR)4,5,21-51
Portuguese Weight
Control Registry
(PWCR)6,52-54
German Weight
Control Registry
(GWCR)8,55-58
Finnish Weight
Control Registry
(FWCR)7,59-61 MedWeight62-67
Country
Designation United States Portugal Germany Finland Greece
Duration of
weight loss
maintenance at
baseline
68.3 ± 88.1 mo
(n = 3683)4
28.3 ± 29.6 mo
(n = 225)
5.61 ± 5.78 y
(n = 381)56
53.2% (2 to 3 y);
20.3% (4 to 5 y);
15.8% (6 to 8 y);
10.7% (≥9 y).
4.6 ± 4.3 y (only the
group of
maintainers)
(n = 169)63
Weight loss
maintenance at
follow-up
5-y follow-up
(WLM ≥ 10%): 88%
1-y follow-up
(WLM ≥ 3%): 60.5%
(n = 105)e
1-y follow-up
(WLM ≥ 5%): 60.9%
(n = 440)e
- 1-y follow-up
(WLM ≥ 10%): 67%
(n = 800)e10-y follow-up
(WLM ≥ 10%): 87%
(n = 2886)e
Weight control registries' procedures
Period of
recruitment
Ongoing Ongoing October 2009-April
2011
January 2012-August
2013
Ongoing
Inclusion criteria (a) ≥18 y; (b) must
have maintained a
weight loss of
≥13.6 kg (30 lb) for
≥1 y.f
(a) Portuguese
nationality; (b)
18-65 y; (c)
maintained ≥5 kg
intentional weight
loss (on the last
15 y of their adult
lives) for ≥1 y
(independently of
their initial body
weight).f
(a) ≥18 y; (b) lifetime
maximum weight
corresponding to
BMI ≥ 30 kg m−2
(excluding
pregnancy); (c)
intentionally lost
≥10% of their
maximum weight at
any time of their
lives and maintained
it for ≥1 y.f
(a) 18-60 y; (b)
BMI ≥ 30 kg m−2
before initiating
weight loss; (c)
weight loss ≥10%
lasting ≥2 y.f
(a) 18-65 y; (b)
maximum
BMI ≥ 25 kg m−2; (c)
intentionally lost
≥10% of their
starting weight
(maintainers ≥ 10%
for ≥1 y; regainers =
currently at a
weight ≥ 95% of
their maximum
body weight).f
Exclusion criteria - (a) BMI <18.5 kg m−2
(after weight loss)
- (a) Bariatric surgery;
(b) drug treatment
for obesity
(a) Body weight
between 90%-95%
of their maximum
weight; (b)
pregnancy
Assessments
(frequency)
Annually (for 5 y).
Participants may
optionally reconsent
to providing another
5 y of self-reported
weight change only.
Baseline + 1-y
follow-up
Baseline + 1 y + 2-y
follow-up
Baseline Baseline + 1 y + 5-ye
follow-up
aParticipants' characterization is reported using data from the reference with the larger sample size (unless it is indicated).
bMaximum sample size known is over 10 000 participants.
cMaximum sample size known is 402 participants.
dMaximum sample size known is 756 participants.
eThis information was provided by the principal investigator of the weight control registry.
fWeight and weight loss are self-reported by the participants.
4 PAIX~aO ET AL.
chosen because it is a comprehensive tool to systematically describe
the cognitive and behavioural strategies used by individuals
attempting to manage their weight.68 Only the domains including at
least one strategy were shown. One additional domain was included—
dietary choices—as some of the reported strategies did not fit within
any existing domain. Some strategies seemed to fit in more than one
domain; nevertheless, by agreement, we have selected the mostappropriate one.
TABLE 2 Cognitive and behavioural weight management strategies used by participants of weight control registries
Domains
Strategies
Weight Loss Strategies Weight Loss Maintenance Strategies
Number of
Studies n
Prevalence
(%) References
Number of
Studies n
Prevalence
(%) References
Dietary choices
Increase vegetable consumption 2 546 86.6 53,61 1 388 88.8 53
Regular breakfast intakea,24 1 388 89.8 53 1 388 96.6 53
Regular soup intake 1 388 50.5 53 1 388 50.3 53
Increase protein-rich foods
consumption (eg, eggs, fish, and
meat)a,53
1 388 36.0 53 1 388 43.5 53
Increase fibre-rich foods consumption 1 388 77.0 53 1 388 83.6 53
Energy compensationb
Physical activity/exercisec 3 3683 88.6 4,5,38 1 388 67.5 53
Using stairs rather than elevators 1 388 45.7 53 0 - - -
Walk instead of driving/taking public
transportationa,53
1 388 38.0 53 0 - - -
Parking away from destination 1 388 20.4 53 0 - - -
Goal setting
Establishing specific goals (eg,
regarding weight loss and physical
activity)a,53
1 388 60.6 53 1 388 49.1 53
Imitation (modelling)
Followed a diet programme (obtained
from a fad book, magazine or
another person)d
2 2964 23.6 40,63 0 - - -
Information seeking
Conscious food selection (eg, read
labels)
1 388 79.8 53 1 388 72.7 53
Seek weight loss information online 1 158 4.4 59 0 - - -
Diet/exercise books/magazines 0 - - - 1 2228 72.4 5
Motivation
Kept picture of self in a prominent
place
0 - - - 1 931 23.6 31
Lost weight by selfd 3 356 68.8 52,59,63 0 - - -
Planning content
Healthy foods available at home (eg,
fruits and vegetables)a,53,e
1 388 92.7 53 2 1319 89.7 31,53
Few high-fat foods available at home 0 - - - 1 931 83.2 31
Regulation—restrictions
Follow a special/fad dietd 3 1664 16.2 21,38,63 1 893 17.0 26
Reduce portion sizesa,53 2 546 72.5 53,61 1 388 64.6 53
Decrease alcohol intake 1 158 34.8 61 0 - - -
Decrease intake of soft drinks 1 158 53.8 61 0 - - -
(Continues)
PAIX~aO ET AL. 5
TABLE 2 (Continued)
Domains
Strategies
Weight Loss Strategies Weight Loss Maintenance Strategies
Number of
Studies n
Prevalence
(%) References
Number of
Studies n
Prevalence
(%) References
Limit intake of certain types of foods 1 891 84.6 21 1 893 93.1 26
Limit intake to only 1 or 2 types of
foods
1 891 6.1 21 0 - - -
Limit percentage of daily energy from
fat
1 773 33.1 38 1 893 37.8 26
Reduce/eliminate carbohydrate-rich
foods (eg, rice, pasta, and bread)a,53
1 388 47.9 56 1 388 35.4 53
Reduce sugary foodsa,53,e,f 2 388 86.5 53,61 1 388 84.1 53
Reduce fatty foodsg 2 388 86.7 53,61 1 388 86.0 53
Reduce fat in
meals/confection/seasoning
1 388 84.1 53 1 388 83.8 53
Replace caloric sauces for less-caloric
alternatives (eg, squeezed lemon
juice)
1 388 66.1 53 1 388 69.8 53
Decrease meals at restaurants 1 388 45.4 53 2 1319 30.6 31,53
Avoided friends with excess weight 0 - - - 1 931 4.0 31
Regulation—rule setting
Regular meal frequency 2 546 72.5 53,61 1 388 80.8 53
Spent more time with normal-weight
friends
0 - - - 1 931 7.4 31
Spent more time with friends who
exercise
0 - - - 1 931 24.8 31
Restraint
Decrease the quantity of all types of
food eaten
1 891 57.8 21 1 893 50.5 26
Self-monitoring
Count calories 2 1279 27.7 21,53 2 1281 28.6 26,53
Count fat (g) 1 891 26.7 21 1 893 31.1 26
Self-weighinga,27,48,53,h 2 546 79.5 53,61 3 1287 73.0 31,52,61
Record dietary intake/physical
activitya,53,e
1 388 27.2 53 2 1319 35.9 31,53
Support: motivational
Support from family 0 - - - 1 158 63.9 59
Support from friends 0 - - - 1 158 49.4 59
Support: professional
Attend a weight control programme 3 3162 37.6 40,52,63 1 2228 32.9 5
Self-help/weight control group 3 3320 8.0 40,52,59 1 158 19.6 59
Advice from a health care
professionald,i,j
4 826 46.0 30,40,59,63 1 158 31.0 59
Help from a personal trainer/other
professionalsd
3 3122 11.4 40,59,63 0 - - -
Hypnosis 1 2228 1.2 5 0 - - -
Weight management aids
Meal substitutes (eg, shakes and bars)d 3 1281 13.8 26,53,63 2 1281 7.2 26,53
Weight loss medicationd 2 2964 7.3 40,63 1 2228 1.0 5
(Continues)
6 PAIX~aO ET AL.
The sociodemographic, behavioural, and psychological corre-
lates of the magnitude of WLM (ie, weight change expressed in
kilograms or percentage) were also summarized in tabular form,
according to (a) the number of studies that assessed each correlate
and (b) the association effect found, namely, “no association”, “pos-
itive association”, or “negative association” (Table 3). All associa-
tions identified through Pearson and Spearman correlations were
considered. In some specific cases, linear and multiple regressions,
odds ratio/relative risk, and χ2 (with post-hoc tests) were also con-
sidered. Since different studies from the same registry reported dif-
ferent statistical analyses (with different sample sizes and in
different assessment moments) using the same correlate, all the
tested associations were included. Because of the limited number
of studies reporting each strategy and correlate, we did not con-
duct meta-analyses.
3 | RESULTS
The literature search yielded a total of 2992 records. Fifteen arti-
cles, identified through manual searches and cross-referencing,
were added, leading to a total of 3007 potential articles (Figure 1).
After removal of duplicates (n = 1324), 1683 articles were assessed
for eligibility. Of these, 1524 were excluded based on title/abstract
screening, leaving 159 eligible for full-text screening. Fifty-two arti-
cles (published between 1997 and 2018) met eligibility criteria and
were included in the present review.
3.1 | Methodological appraisal
The overall methodological quality of the 52 included studies was
rated as moderate and weak in 48 and 4 studies, respectively. All
study designs were rated as moderate since they were all observa-
tional studies. Similarly, all were rated as weak for selection bias,
since registry participants are volunteers and therefore not likely to
be representative of the target population. Thirteen studies scored
moderate in terms of withdrawals and dropouts. The other 39 were
not rated as they had a cross-sectional design. Concerning adjust-
ment for confounders, two studies were rated as weak and 50 were
rated as strong. Two studies scored weak on data collection, as
they did not provide information on measures of validity or reliabil-
ity; four were classified as moderate and 46 as strong. Most stud-
ies (k = 51) were classified as strong regarding the use of
appropriate statistical analyses. One study was rated as weak
because it did not report the statistical analyses used. Fifty studies
were rated as strong and two as moderate for reporting. Table S1
provides a detailed classification of each domain and the overall
methodological quality of each study.
3.2 | Weight control registries' and participants'
characteristics
Characteristics of the five weight control registries found and the
sociodemographic characteristics of their participants are summa-
rized in Table 1 and in Table S2. The first registry was
TABLE 2 (Continued)
Domains
Strategies
Weight Loss Strategies Weight Loss Maintenance Strategies
Number of
Studies n
Prevalence
(%) References
Number of
Studies n
Prevalence
(%) References
Surgeryd 2 2228 3.7 5,63 0 - - -
Weight loss supplementsk,53 1 388 15.1 53 1 388 11.5 53
Note. The prevalence of each strategy is reported using combined data derived from the largest sample size reported in each registry.
aThis strategy was found to be positively associated with weight control (loss, maintenance, or both) in terms of magnitude (reference of the article/s).
bPhysical activity was considered in the Energy Compensation domain because this strategy is commonly used to compensate energy intake as a way to
control weight.
cStudies of Ogden et al5 and Klem et al38 were not accounted for sample size or prevalence rates because of assessment differences (separate nonmutually
exclusive values for exercising at home,with friends, or with a structured group).
dStudy of Karfopoulou et al63 was not accounted for sample size or prevalence rates because the exact frequencies were not reported.
eAssociation observed only in women.
fStudy of Soini et al61 was not accounted for sample size or prevalence rates because of assessment differences (separate nonmutually exclusive values for
candies, sweet pastries, and fast carbohydrates).
gStudy of Soini et al61 was not accounted for sample size or prevalence rates because of assessment differences (separate nonmutually exclusive values for
fast food, high-fat cold cuts/sausages, and high-fat cheeses).
hStudy of Soini et al61 reports self-weighing as monitoring weight at least once a week.
iAssisted weight loss was interpreted as receiving advice from a health care professional.
jStudy of LaRose et al40 was not accounted for sample size or prevalence rates because of assessment differences (separate nonmutually exclusive values
for advice from different health care professionals).
kThis strategy was found to be negatively associated with weight control (loss, maintenance, or both) in terms of magnitude (reference of the article/s).
PAIX~aO ET AL. 7
TABLE 3 Association of sociodemographic, behavioural, and psychological characteristics with the magnitude of weight loss maintenance
Magnitude of Weight Loss Maintenance
Correlates Number of Studies No Association
Significant Association
Positive Negative
Sociodemographic
Socioeconomic status 1 61,a,b
Level of education 1 48,c
Ethnic/racial background 1 48,a,c
Age 1 24,d
Weight history
Body weight 1 24,d
Lifetime maximum body weight 1 48,c
Magnitude of initial weight loss 3 48,c 24,d 30,d
Duration of initial weight loss maintenance 3 24,d
48,a 30,d
Trying to lose weight at study entry (rather than maintain) 1 30,d
Medical trigger (to weight loss) 1 29,d,e
Behavioural
Physical activity 5 23,d 24,d 48,c,f 53,a,g 35,h,i
Energy intake 3 23,d 24,d 35,h,i
Protein intake 1 53,a,j
Fat intake 3 23,d 24,d 48,c
Carbohydrate intake 1 24,d
Sweets consumption 1 23,d
Television viewing 1 23,d
Fast food consumption 1 24,d
Coffee or caffeinated beverages 1 58,a,b
Psychological
Weight-related teasingk 1 56,b,e
Eating restraint 2 56,b,e 48,c,g
Disinhibition 3 33,d 48,c,g 30,d
Internal disinhibition 2 41,l 42,d
External disinhibition 2 41,l 42,d
Emotional eating 1 56,b,e
External eating 1 56,b,e
Dieting consistency 1 28,d,e
Neuroticism 1 60,a,j
Conscientiousness 1 60a,j
Binge eating 1 47,a,b
Note. Having a healthy eating pattern,64,a,m,n sleep quality,62,a,m and internal orientation (locus of control)67,a were positively associated with weight loss
maintenance status. Total support65,a was negatively associated with weight loss maintenance status. Total sabotage65,a was not associated with weight
loss maintenance status.
aWeight loss maintenance (WLM) at baseline.
bWLM expressed as a difference in BMI.
cWLM over 10-y follow-up.
dWLM at 1-y follow-up.
eWLM at 2-y follow-up.
fLeisure-time physical activity.
gModerate-plus-vigorous physical activity.
hWLM at 3-y follow-up.
8 PAIX~aO ET AL.
implemented in the United States in 1993, while the others
were implemented between 2008 and 2012 in four European
countries. Recruitment procedures, use of incentives, and eligibility
slightly differed between registries. Across the five registries, age
(18 years and older) was a common requisite for entering. The
required WL for entry, however, differed between registries.
Germany, Finland, and Greece requested an initial WL of at least
10%, whereas Portugal and the United States established a WL of
at least 5 and 13.6 kg (30 lb), respectively. Some registries
(Germany, Finland, and Greece) also required having excess weight
prior to WL as an entry criterion. Four registries required
maintaining the weight lost for at least 1 year, but the Finnish reg-
istry required at least 2 years of WLM. The MedWeight study
(Greece) distinguishes maintainers from regainers at study entry, ie,
people who have lost weight but regained some part of it (weight
at study entry ≥95% of their maximum body weight). The fre-
quency and methods of assessment also differed between regis-
tries. The Finnish registry has a single assessment moment, while
the others have at least two assessment moments. The US registry
assesses participants annually for 10 years. All registries collect
information on sociodemographics, lifestyle habits, personal and
familiar medical history, and psychometrics. They all include some
kind of dietary intake and structured physical activity measurement.
Anthropometric data are generally self-reported, except in the
Portuguese registry where individuals are objectively measured
(weight, height, and waist circumference) and in the US registry
where subsets of participants were studied in-person for specific
studies.
The US registry is the largest, reporting over 10 000 participants.
The four European registries have several hundred participants each.
From weight history assessments, the registry participants had maxi-
mum BMIs between 32.4 and 36.3 kg m−2 and BMIs between 25.1
and 30 kg m−2 at registry entry. Participants in all registries had vari-
able average WLs (14.5-32.4 kg) and variable time periods over which
the WL was maintained (28-68 months). WLM at follow-up (consider-
ing maintenance of at least 3% to 10% WL, depending on the criteria
used by each registry) was observed in 60.5% to 88% of the
participants.
iBaseline levels were not predictive of weight regain. Decreased physical activity levels or increased energy intake over time was associated with 3-y
weight regain.
jAssociation observed only in women.
kRetrospective weight-related teasing during childhood and adolescence.
lWLM over 5-y follow-up.
mAssociation observed only in men.
nHealthy eating pattern = higher consumption of unprocessed cereal, fruit, vegetables, eggs, olive oil, beverages (such as coffee and tea), low-fat dairy, and
low-fat cheese; and lower consumption of processed cereal, sweets, spreads/sauces, high-fat cheese, and junk food.
F IGURE 1 Flow diagram of studies
PAIX~aO ET AL. 9
3.3 | Cognitive and behavioural weight
management strategies
Thirteen studies across four countries reported strategies used by
participants for WL and WLM (Table 2). From these studies,
51 strategies, grouped in 14 domains of the OxFAB taxonomy,
were identified.
The most frequently reported strategies (≥80%) for WL were
classified in the following domains: planning content (having healthy
foods available at home), dietary choices (regular breakfast intake
and increasing vegetable consumption), energy compensation (engag-
ing in physical activity/exercise), and regulation—restrictions (reducing
the consumption of sugary and fatty foods, limiting intake of certain
types of foods, and reducing fat in meals) domains. The least fre-
quently reported strategies (≤20%) were in the following domains:
support—professional (hypnosis, self-help/help from a weight control
group, and help from a personal trainer or other professional),
weight management aids (surgery, taking WL medication, using meal
substitutes, and consuming WL supplements), information seeking
(seeking WL information online), and regulation—restrictions (limiting
intake to only one or two types of food and following a special or
fad diet).
For WLM, the majority of participants (>80%) relied on regular
breakfast intake, increasing the consumption of vegetables and fibre-
rich foods (dietary choices domain); limiting intake of certain types of
foods, reducing the consumption of fatty and sugary foods, and
reducing fat in meals (regulation—restrictions domain); having healthy
foods and few high-fat foods available at home (planning content
domain); and having a regular meal frequency (regulation—rule setting
domain). Less than 20% of participants reported taking WL medica-
tion, using meal substitutes, and consuming WLsupplements (weight
management aids domain); avoiding friends with excess weight and
following a special or fad diet (regulation—restrictions domain); spend-
ing more time with normal-weight friends (regulation—rule setting
domain); and having help from a weight control group (support—
professional domain).
3.4 | Correlates of the magnitude of WLM
Table 3 shows a data analytic synthesis of the 30 sociodemographic,
behavioural, and psychological correlates of the magnitude of WLM
tested in 16 of 52 studies. Physical activity was the most frequently
studied correlate (k = 5) with all of the studies reporting a positive
association with the magnitude of WLM. Energy intake and fat intake
were tested as correlates of the magnitude of WLM in three studies
each and were found to be negatively associated in all of the studies.
The amount of sustained WL prior to study entry was also tested as
a correlate of the magnitude of WLM at follow-up (k = 3): Only one
study showed a positive association. The duration of WLM before
entering the registry was tested in three studies, with all showing
positive associations with the magnitude of WLM. General eating
disinhibition (k = 3) and internal and external disinhibition (k = 2)
were also tested as correlates of the magnitude of WLM, with gen-
eral and internal eating disinhibition being identified as consistent
negative correlates. Several variables were identified as positive cor-
relates of the magnitude of WLM, although in less than three studies:
body weight, lifetime maximum body weight, medical trigger, protein
and carbohydrate intake, dieting consistency, neuroticism, and con-
scientiousness (Table 3); and regular breakfast intake, increasing
protein-rich foods' consumption, walking instead of driving/taking
public transportation, establishing specific goals, reducing portions
size, reducing/eliminating carbohydrate-rich foods, and self-weighing
(Table 2). The following strategies were associated with the magni-
tude of WLM only in women: having healthy foods available at
home, reducing sugary foods, and recording dietary intake/physical
activity (Table 2).
4 | DISCUSSION
This systematic review identified sociodemographic, cognitive, and
behavioural characteristics of successful WL maintainers from five
country-specific weight control registries, as well as correlates of
the magnitude of WLM. To the best of our knowledge, this is the
first review providing a comprehensive comparison of the existing
weight control registries and their participants, allowing the identi-
fication of common key influential characteristics. Information from
weight control registries is useful in guiding further prospective
research and may be useful in helping direct future public health
and weight management interventions and policies.
Fifty-two studies from five weight control registries (the United
States, Portugal, Germany, Finland, and Greece) were included.
Although having a common goal of studying successful maintenance
of WL in their populations, each registry has unique recruitment
strategies, enrolment criteria, and assessments. Across participants
from four weight control registries, 51 different personal strategies
were reported for WL and WLM. The most frequently reported
were having healthy foods available at home, having regular break-
fast intake, increasing vegetables' consumption, reducing the con-
sumption of sugary and fatty foods, and reducing fat in meals
(within the planning content, dietary choices, and regulation—
restrictions domains of the OxFAB taxonomy). Finally, 30 different
sociodemographic, behavioural, and psychological correlates of
the magnitude of WLM were identified; the most frequently
studied was physical activity, which showed a consistent positive
association.
These weight control registries, while not providing a quantitative
measure of success, have demonstrated that some people are
succeeding in long-term WL. This information can provide motivation
and hope to those struggling to achieve long-term weight reductions.
All registries have set a realistic, clinically significant minimum amount
of WL for eligibility2 (for example, in Portugal, a 5-kg WL represents
more than 5% WL for most individuals with excess weight),69,70
suggesting that participants improved their lifestyle and health. How-
ever, participants have used a variety of different (and, to some
10 PAIX~aO ET AL.
extent, individualized) behavioural strategies to achieve WL and
WLM. These results suggest that there is no “one size fits all”
approach for WL and WLM. Instead, participants seem to rely on dif-
ferent sets or combinations of cognitive and behavioural strategies,
with some uncommon behaviours being very important for some
participants.
In line with the most recent obesity treatment guidelines,2,71,72
the most frequently reported strategies encompassed reductions in
energy intake and increases in energy expenditure (through physical
activity/exercise). In fact, physical activity, total energy intake, and
also fat intake were the most consistent behavioural correlates of the
magnitude of WLM, which is corroborated by a recent systematic
review on determinants of WLM.11 These results suggest, in line with
previous guidelines (eg, Donnelly et al73), that there is likely a dose-
response effect, with greater WLs being achieved and maintained
with greater doses of physical activity and lower energy and fat intake
(despite the cross-sectional data analysis).
Other popular strategies among WL maintainers related to
planning behaviour (having healthy foods available at home) and
improving the quality of the diet by making healthier choices (eg,
increasing vegetable consumption), which are also aligned with
evidence-based guidelines for weight management (eg, Jensen
et al2). While the literature is mixed with regard to the importance
of eating breakfast for obesity,74-77 it was positively associated with
the magnitude of WLM. The role of protein in obesity treatment is
also controversial.11,78,79 However, in this review, the consumption
of protein-rich foods and protein intake was also found to be posi-
tively associated with the magnitude of WLM. Consistent with prior
research,11,80,81 results from weight control registries find reducing
portion sizes, as a means of cutting calories, self-monitoring/self-
weighing (which inform on the individual's progress towards his/her
goal, increases awareness and perceived control over one's life), and
specific goal setting for eating and physical activity to be positively
related with the magnitude of WLM. These strategies are rec-
ommended by weight management guidelines72 and seem to act
synergistically, given that when individuals monitor their progression
towards their goal, they can adjust their behavioural efforts
(if/when needed) and more easily attain their goals. Eating and
physical activity goals should be, however, realistic and
individualized,2 to prevent individuals from abandoning the weight
management process.
Importantly, few participants reported using weight manage-
ment aids (meal substitutes, WL pills, and supplements), and, in fact,
taking WL supplements was shown to be negatively associated with
weight control in one of the included studies. Other studies found
limited or no evidence on the effectiveness of meal substitutes or
WL supplements on WLM and even reported some potential health
risks.13,82,83
It is noteworthy that the most frequent strategies for WL were
often also used for WLM. It remains unclear whether maintaining
WL involves primarily a continuation of the behaviours initially
adopted,84 as the present results suggest, or whether it requires a
behavioural set different from that needed to achieve initial WL.85
It is certainly possible that many of these successful maintainers still
wished to lose additional weight and therefore revisited most of the
strategies they adoptedin the first place. Nevertheless, most of
these strategies are aligned with important theoretical assumptions
of behaviour change maintenance involving more internal forms of
motivation, active self-regulation, habitual cue driven responses, and
boundary conditions including resources and environmental
factors.86
Other notable correlates of the magnitude of WLM were identi-
fied in these registries. Consistent with other research,87 the duration
of WLM at study entry was consistently and positively associated
with the magnitude of WLM. This could suggest that maintenance
becomes easier over time, perhaps because the newly adopted weight
control behaviours become habits (automatic), demanding less con-
scious effort.86 Medical-triggered WL also seems to be particularly
well maintained, perhaps because individuals perceive that their prior
weight was the cause of the medical crisis.88 Additionally, eating in
response to emotional cues seems to be consistently negatively asso-
ciated with the magnitude of WLM, corroborating other studies.11,89
This behavioural trait is probably related with overeating and binge
eating episodes,90 which was also found to be negatively correlated
with WLM in this review. Some psychological traits, such as conscien-
tiousness, were found to be positively associated with WLM only in
women. Conscientiousness (characterized by self-control) has been
found in previous studies to facilitate the adoption/maintenance of
healthier behaviours over time and to lead to greater WL.91 The cul-
tural and sex specificities underlying the relationship between weight
and personality92,93 may explain results in this and in other
studies.93,94
4.1 | Strengths and limitations
The main strength of this systematic review is the characterization of
all existing weight control registries worldwide (with published
results) and, therefore, of nationally recruited samples of successful
WL maintainers from different regions. Although sample sizes are
considerably large, their nature (volunteers) precludes the generaliza-
tion of these results to the population under scrutiny—nationwide
successful WL maintainers. Recruiting individuals through web-based
platforms allows the recruitment of more heterogeneous samples (eg,
individuals from different counties/regions). However, it also limits
participation to individuals with certain levels of digital literacy,
potentially narrowing the sample characteristics. Additionally, this
type of study is subject to selection bias towards more motivated
individuals.
Although important characteristics, strategies, and correlates
were identified (through valid and reliable instruments), discrepancies
across registries, particularly regarding enrolment criteria and assess-
ments, represent an important limitation when establishing cross-
comparisons. Research in different countries and other cultural
settings, with standardized methodologies and tools, would add to the
generalizability by increasing accuracy and comparability.
PAIX~aO ET AL. 11
The self-reported nature of most data (including for registry eligi-
bility) can lead to response bias associated with recall difficulties,
social desirability, and underestimations or overestimations.95,96 Nev-
ertheless, since there is no intervention with the participants, and
most registries do not offer financial incentives or other major bene-
fits from entering, we assume there is little reason for participants to
misreport information, at least their weight history. Additionally, some
studies show that self-reported data, such as weight and height,
strongly correlate with objectively measured data.97
Finally, the observational nature of the registries and the cross-
sectional design of most studies, even though with a retrospective or
prospective nature, prevents drawing firm conclusions about
the causal direction of the associations between correlates and the
magnitude of WLM. The possibility of reverse causality cannot be
excluded, and therefore, results should only be interpreted as sugges-
tive and supportive.
4.2 | New project: The International Weight
Control Registry
It is clear that many factors can affect WL and WLM. It is also clear
that differences among country-specific registries sometimes make it
difficult to draw general conclusions. Recognizing these limitations,
researchers at several universities in the United States, Europe, and
Australia have recently combined forces to create the International
Weight Control Registry (IWCR). By bringing together researchers
from different parts of the world and with expertise in different areas,
it may be possible to extend the scope of understanding of factors
involved in WL and WLM. The IWCR consists of a database, accessi-
ble online, where qualified individuals can complete a comprehensive
series of questionnaires about their weight management and be
followed up over time. These questionnaires currently cover a broad
range of variables from basic demographics, weight history, eating and
physical activity behaviours, executive function, stress reactivity, and
identity to environmental/contextual circumstance and more. Addi-
tional measures can be added over time. The IWCR aims to assess
between-country differences and similarities in how people succeed
in long-term WL. It also aims to identify how cultural, social, political,
and environmental factors in different populations within different
countries may impact weight maintenance success. This registry seeks
to understand both what people did to become successful and how
they were able to make and sustain these behavioural changes in the
environment in which they live in. More information about this regis-
try will be available soon to the scientific community, and academic
centres throughout the world will have opportunities to become col-
laborating centres in this project.
4.3 | Conclusions and implications
This systematic review describes five country-specific weight con-
trol registries across the world and identifies key sociodemographic,
cognitive, and behavioural characteristics of successful WL main-
tainers. Additionally, it reports on important correlates of the mag-
nitude of WLM, providing insight into the public's response to the
(excess) weight problem and suggesting evidence-based clues for
future public health and obesity prevention and treatment
initiatives.
In order to capture a better picture of real-world WL maintainers,
more countries, with different sociocultural, physical, and policy
milieus, should consider joining the IWCR or developing their own
weight control registries, preferentially with standardized tools and
methodologies to increase accuracy and comparability between them.
Additional determinants influencing WLM through their effect on
behaviour (eg, social, physical, and macroenvironmental) should be
explored in these registries. This will help bridge the monitoring of
successful WLM in the adult population, thus informing and advancing
future clinical and research practice.
ACKNOWLEDGEMENTS
This study was funded by the Foundation for Science and Technology
Portugal (PTDC/DES/72317/2006, 2008-2011).
ORCID
Catarina Paix~ao https://orcid.org/0000-0002-0531-2412
Carlos M. Dias https://orcid.org/0000-0002-0206-5874
Rui Jorge https://orcid.org/0000-0002-5261-2688
Eliana V. Carraça https://orcid.org/0000-0002-5789-811X
Mary Yannakoulia https://orcid.org/0000-0003-2171-7337
Martina de Zwaan https://orcid.org/0000-0002-7918-6957
Sirpa Soini https://orcid.org/0000-0001-6190-1177
James O. Hill https://orcid.org/0000-0003-4690-2264
Pedro J. Teixeira https://orcid.org/0000-0001-7202-0527
Inês Santos https://orcid.org/0000-0002-1638-8551
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SUPPORTING INFORMATION
Additional supporting information may be found online in the
Supporting Information section at the end of this article.
How to cite this article: Paix~ao C, Dias CM, Jorge R, et al.
Successful weight loss maintenance: A systematic review of
weight control registries. Obesity Reviews. 2020;1–15. https://
doi.org/10.1111/obr.13003
PAIX~aO ET AL. 15
https://doi.org/10.1111/obr.13003
https://doi.org/10.1111/obr.13003
	Successful weight loss maintenance: A systematic review of weight control registries
	1 INTRODUCTION
	2 METHODS
	2.1 Eligibility criteria
	2.2 Search strategy and study selection
	2.3 Quality assessment
	2.4 Data extraction
	2.5 Data synthesis
	3 RESULTS
	3.1 Methodological appraisal
	3.2 Weight control registries' and participants' characteristics
	3.3 Cognitive and behavioural weight management strategies
	3.4 Correlates of the magnitude of WLM
	4 DISCUSSION
	4.1 Strengths and limitations
	4.2 New project: The International Weight Control Registry
	4.3 Conclusions and implications
	ACKNOWLEDGEMENTS
	REFERENCES
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 /FRA <FEFF005500740069006c006900730065007a00200063006500730020006f007000740069006f006e00730020006100660069006e00200064006500200063007200e900650072002000640065007300200064006f00630075006d0065006e00740073002000410064006f006200650020005000440046002000710075006900200064006f006900760065006e0074002000ea0074007200650020007600e9007200690066006900e900730020006f0075002000ea00740072006500200063006f006e0066006f0072006d00650073002000e00020006c00610020006e006f0072006d00650020005000440046002f0058002d00310061003a0032003000300031002c00200075006e00650020006e006f0072006d0065002000490053004f00200064002700e9006300680061006e0067006500200064006500200063006f006e00740065006e00750020006700720061007000680069007100750065002e00200050006f0075007200200070006c007500730020006400650020006400e9007400610069006c007300200073007500720020006c006100200063007200e9006100740069006f006e00200064006500200064006f00630075006d0065006e00740073002000500044004600200063006f006e0066006f0072006d00650073002000e00020006c00610020006e006f0072006d00650020005000440046002f0058002d00310061002c00200076006f006900720020006c00650020004700750069006400650020006400650020006c0027007500740069006c0069007300610074006500750072002000640027004100630072006f006200610074002e0020004c0065007300200064006f00630075006d0065006e00740073002000500044004600200063007200e900e90073002000700065007500760065006e0074002000ea0074007200650020006f007500760065007200740073002000640061006e00730020004100630072006f006200610074002c002000610069006e00730069002000710075002700410064006f00620065002000520065006100640065007200200034002e0030002000650074002000760065007200730069006f006e007300200075006c007400e90072006900650075007200650073002e>/ITA (Utilizzare queste impostazioni per creare documenti Adobe PDF che devono essere conformi o verificati in base a PDF/X-1a:2001, uno standard ISO per lo scambio di contenuto grafico. Per ulteriori informazioni sulla creazione di documenti PDF compatibili con PDF/X-1a, consultare la Guida dell'utente di Acrobat. I documenti PDF creati possono essere aperti con Acrobat e Adobe Reader 4.0 e versioni successive.)
 /JPN <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>
 /KOR <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>
 /NLD (Gebruik deze instellingen om Adobe PDF-documenten te maken die moeten worden gecontroleerd of moeten voldoen aan PDF/X-1a:2001, een ISO-standaard voor het uitwisselen van grafische gegevens. Raadpleeg de gebruikershandleiding van Acrobat voor meer informatie over het maken van PDF-documenten die compatibel zijn met PDF/X-1a. De gemaakte PDF-documenten kunnen worden geopend met Acrobat en Adobe Reader 4.0 en hoger.)
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 /PTB <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>
 /SUO <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>
 /SVE <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>/ENG (Modified PDFX1a settings for Blackwell publications)
 /ENU (Use these settings to create Adobe PDF documents that are to be checked or must conform to PDF/X-1a:2001, an ISO standard for graphic content exchange. For more information on creating PDF/X-1a compliant PDF documents, please refer to the Acrobat User Guide. Created PDF documents can be opened with Acrobat and Adobe Reader 4.0 and later.)
 >>
 /Namespace [
 (Adobe)
 (Common)
 (1.0)
 ]
 /OtherNamespaces [
 <<
 /AsReaderSpreads false
 /CropImagesToFrames true
 /ErrorControl /WarnAndContinue
 /FlattenerIgnoreSpreadOverrides false
 /IncludeGuidesGrids false
 /IncludeNonPrinting false
 /IncludeSlug false
 /Namespace [
 (Adobe)
 (InDesign)
 (4.0)
 ]
 /OmitPlacedBitmaps false
 /OmitPlacedEPS false
 /OmitPlacedPDF false
 /SimulateOverprint /Legacy
 >>
 <<
 /AddBleedMarks false
 /AddColorBars false
 /AddCropMarks false
 /AddPageInfo false
 /AddRegMarks false
 /ConvertColors /ConvertToCMYK
 /DestinationProfileName ()
 /DestinationProfileSelector /DocumentCMYK
 /Downsample16BitImages true
 /FlattenerPreset <<
 /PresetSelector /HighResolution
 >>
 /FormElements false
 /GenerateStructure false
 /IncludeBookmarks false
 /IncludeHyperlinks false
 /IncludeInteractive false
 /IncludeLayers false
 /IncludeProfiles false
 /MultimediaHandling /UseObjectSettings
 /Namespace [
 (Adobe)
 (CreativeSuite)
 (2.0)
 ]
 /PDFXOutputIntentProfileSelector /DocumentCMYK
 /PreserveEditing true
 /UntaggedCMYKHandling /LeaveUntagged
 /UntaggedRGBHandling /UseDocumentProfile
 /UseDocumentBleed false
 >>
 ]
>> setdistillerparams
<<
 /HWResolution [2400 2400]
 /PageSize [612.000 792.000]
>> setpagedevice