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 |
| 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% 10-y follow-up (WLM ≥ 10%): 87% (n = 2886)e |
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)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 |
a
Participants’ characterization is reported using data from the reference with the larger sample size (unless it is indicated).
b
Maximum sample size known is over 10 000 participants.
c
Maximum sample size known is 402 participants.
d
Maximum sample size known is 756 participants.
e
This information was provided by the principal investigator of the weight control registry.
f
Weight and weight loss are self-reported by the participants.