Resumen de Efeito da privação e restrição alimentar no valor reforçador do alimento: um estudo exploratório

Vivian Costa Resende Cunha, Sônia Maria Mello Neves

• English

  Food deprivation (calorie reduction) and food restriction (limited access to specific foods) have been essential in nutritional treatments for obesity and overweight. In a previous study, Raynor & Epstein (2003) found that food deprivation influence the reinforcing value of food but not food restriction. Although Reis and Havercamp (1996) have suggested that individual differences in reinforcer value should not be tested under deprivation, since this variable increases overall reinforcing value of food, the effects of inadequate eating behaviors on food value have not yet been studied in a context of deprivation and/or food restriction. Thus, this study had the objective of evaluating whether food deprivation (Dep) and/or restriction (Res), combined or not with disordered eating (DE), would influence the reinforcing value of food and the relationship between the hunger report before, during and after the experimental phase and the food choice in the different conditions of deprivation and restriction, with and without changes in psychometric tests. Eight eutrophic women, aged 18 to 27 years, were submitted to the following experimental sessions: Dep/Res, Dep/NRes, NDep/Res, and NDep/NRes, after 8 hours of fasting. Four participants had alterations in eating behaviors and four did not. Alterations in eating behaviors was evaluated using the Periodic Eating Compulsion Scale (PECS) (Freitas, Lopes, Coutinho & Appolinario, 2001), the Eating Attitudes Test (EAT-26) (Biguietti, 2003), and the Restriction Scale (Scagliusi et al., 2005). In condition NDep, participants were offered a drink (350 kcal) and instructed to consume at least half (175 kcal) for a period of 15 minutes, while in condition Dep they were instructed only to remain seated for the same period of time. In condition Res, a meal was placed in front of the participants for 15 minutes, which they could look at and respond to questions, but could not eat. In condition NRes, there was no meal and participants had to remain seated for 15 minutes. After each condition (Dep or NDep and Res or NRes), participants had to classify their hunger in the 100 mm analogue visual scale. Then, a computer game was presented, for which they could get points to trade for food or leisure. The leisure alternative, reinforcers for delivered in a Variable Ratio 2 (VR2) schedule and, in the food alternative, a chain schedule was programmed (VR2, VR4, VR6, VR8, VR10). Results suggest that Priv seems to have influenced more the reinforcing value of food compared to Rest and the effects of DE on food or leisure choice were not clearly identified, pointing to the need for further research

• português

  Este estudo avaliou se privação (Priv) e/ou restrição (Rest) alimentar, combinadas ou não com a presença de comer transtornado (CT), influenciam no valor reforçador do alimento. Oito mulheres, quatro classificadas com CT e quatro sem, foram submetidas às sessões experimentais:

  Priv e Rest, Priv e NRest, NPriv e Rest, NPriv e NRest após jejum mínimo de oito horas.

  Posteriormente, um jogo foi apresentado no qual as participantes poderiam ganhar pontos para trocar por alimento ou lazer. Na alternativa correspondente a lazer, o esquema programado de liberação de pontos foi a Razão Variável 2 (VR2) e na alternativa correspondente ao alimento, um esquema encadeado (VR2, VR4, VR6, VR8, VR10). Antes do início do jogo foi servida, na condição de NPriv, uma bebida. Na Priv, as participantes não consumiram a bebida por quinze minutos. Na condição de Rest, um prato com alimentos foi apresentado durante quinze minutos, sem que pudessem comer e na NRest, não foi apresentado. Resultados sugerem que a Priv parece ter influenciado mais no valor reforçador do alimento comparada à Rest e os efeitos do CT na escolha por alimento ou lazer não foram claramente identificados, apontando a necessidade de novas pesquisas.