Abstract Aim: Grounded on Self-Determination Theory, this study aimed to translate, adapt and validate the Perceived Environmental Supportiveness Scale (PESS) in a sample of Portuguese physical education students. Methods: The global sample was comprised of 964 students (518 females), divided in two groups: the calibration (n = 469) and the validation one (n = 483), all of them enrolled in two Physical Education (PE) classes/week. Results: The analysis provided support for a one factor and 12 items model, which are in line with the values adopted in the methodology (χ² = 196.123, df = 54, p = <.001, SRMR = .035, NNFI = .943, CFI = .954, RMSEA = .074, 90% CI .063-.085). Results express that the models are invariant in all analysis (i.e., calibration vs. validation, male vs. female, and 3rd vs. secondary cycle; three and single factor models). Conclusion: The present study suggests that the PESS with one factor and 12 items has good psychometric properties and can be used to assess perceived need supportive motivational environments provided by PE teachers. Additionally, invariance analysis showed support for the use of the scale in both genders and in the 3rd and secondary cycles.

O Registo Nacional de Controlo do Peso (RNCP) estuda as características dos adultos portugueses com sucesso na manutenção do peso perdido. O presente trabalho compara os comportamentos e estratégias usadas no RNCP com os reportados por participantes do National Weight Control Registry (NWCR), nos EUA. Os 198 indivíduos da amostra (idade: 39,7±11,1 anos; IMC: 26,0±3,9kg/m²), 59% mulheres, completaram um questionário inicial, que incluiu variáveis demográficas, estratégias de perda e de manutenção do peso, atividade física e alimentação. Os indivíduos apresentaram uma perda do peso média de 17,4kg e tempo médio de manutenção de 29 meses. Os participantes no RNCP são, em média, mais novos e mais pesados do que os participantes no NWCR. Em ambos os registos, a alteração conjunta dos hábitos de atividade física e de alimentação foi a estratégia de perda do peso mais usada (82 vs. 89%, no NWCR). No RNCP, 43% das pessoas passou a subir escadas, 91% passou a tomar o pequeno-almoço, 79% a selecionar os alimentos de forma diferente, 74% a reduzir porções e 86% a reduzir a gordura nos alimentos. O dispêndio energético médio com atividade física no RNCP é de 3 422 kcal/semana, correspondendo a cerca de 250min de atividade física moderada ou vigorosa (2 621kcal/semana no NWCR), sendo a ingestão calórica de cerca de 2 200kcal/d (comparada com 1 379 no NWCR). Outras estratégias de manutenção do peso foram: selecionar conscientemente os alimentos (69 vs. 92% no NWCR), limitar alimentos ricos em gordura (87 vs. 38%), limitar as porções (63 vs. 49%), tomar o pequeno-almoço (98 vs. 78%) e automonitorizar o peso (65 vs. 75%). Esta análise revela que as estratégias de perda e manutenção do peso adotadas pelos participantes portugueses apontam globalmente no mesmo sentido que as reportadas pela amostra americana. As diferenças detetadas são discutidas neste artigo.

The aim of this work is to compare participant characteristics and weight loss and weight loss maintenance strategies adopted by an initial cohort of the Portuguese Weight Control Registry (PWCR) with published results from the National Weight Control Registry's (NWCR). Sample includes 198 adults (age: 39.7±11.1 yr; BMI: 26.0±3.9kg/m²), 59% women, who voluntarily registered to the PWCR and completed one initial questionnaire including demographics, methods and strategies used to lose weight and/or to maintain weight, and a laboratory assessment. Individuals meeting inclusion criteria reported a weight loss of 17.4kg, maintained for an average of 29 months. The PWCR sample is younger, heavier, and more gender-balanced than the NWCR sample. Modifying both dietary intake and physical activity (PA) levels was the most common weight loss strategy in Portuguese individuals (82%), while 89% reported it in NWCR. To lose weight, 43% of all PWCR participants started to use stairs, 91% started to eat breakfast every day, 79% chose "better foods", 74% reported "limiting food quantities", and 86% frequently limit fat intake. To keep weight loss, PWCR individuals engaged weekly in 250minutes of moderate and vigorous physical activity and a weekly physical activity energy expenditure of 3422kcal (NWCR: 2621kcal). Other strategies were used: 69% chose "better foods" (NWCR: 92%), 87% frequently limiting fat intake (NWCR: 38%), 63% reported "limiting food quantities" (NWCR: 49%), 98% ate breakfast every day (NWCR: 78%), and 65% weighed themselves at least once a week (NWCR: 75%). Data from the first PWCR cohort show similarities with the larger US sample of successful maintainers but also some differences. This work discusses these differences.

Este estudo descreve o processo de adaptação da versão portuguesa, de 21 itens, da Basic Need Satisfaction in General Scale da teoria de auto-determinação. O instrumento é composto por três subescalas que correspondem às três necessidades básicas (a) competência, (b) autonomia e (c) relações de pertença. Foi administrado em dois estudos independentes, 420 e 408 participantes respectivamente, com amostras de conveniência da comunidade. A primeira fase incluiu tradução, retroversão e retradução; inspecção da equivalência lexical e de conteúdo; e reflexão falada. No processo de adaptação é aferido se a validade de conteúdo está de acordo com a teoria original. O estudo métrico revela valores baixos na consistência interna em algumas das subescalas. Numa análise exploratória inicial, em ambos os estudos, emergem três factores no scree plot, a maioria dos itens apresenta carga factorial apropriada no primeiro factor. Os resultados sugerem que a escala poderá ser utilizada na população portuguesa assumindo os princípios teóricos definidos pelos autores originais e reconhecidos na investigação.

This paper describes the adaptation process of the Portuguese version, comprised of 21 items, of the Basic Need Satisfaction in General Scale of self-determination theory. This instrument consists of three subscales that correspond to the three basic needs of (a) competence, (b) autonomy and (c) relatedness. It was administered in two independent studies, with 420 and 408 participants respectively, with convenience samples extracted from the community. The first phase included translation, back translation and retroversion; inspection for lexical equivalence, content validity and cognitive debriefing. In the adaptation process we evaluated whether the content validity was consistent with the original theory. Psychometric properties reveal low internal consistency in some of the subscales. In an initial exploratory analysis, in both studies, three factors emerged in the scree plot and most of the items displayed appropriate factorial load in the first factor. The results suggest that the scale may be used in the Portuguese population assuming the theoretical principles defined by the original authors and recognized in research.