Influencing Unsuccessful Restrained Eaters' Unhealthy Food Choice:An Inhibition Control Training

Restrained eaters(REs)are highly focused on their weight and can be divided into successful and unsuccessful subgroups(Herman &Polivy,1980).They are often dissatisfied with their weight,and then take a diet to achieve the goal of weight loss.When they face the food,their inhibitory control ability is weak;in the food environment,they are more likely to have strong eating impulses and secrete more saliva compared to normal people(Veenstra&Jong,2010).This carving for food can lead to over eating(Hofmann,Adriaanse,Vohs,& Baumeister,2014;Polivy,& Herman,2003)even when remind them not to eat anything(Stroebe,van Koningsbruggen,Papies,& Aarts,2013)?he goal-conflict model proposes that restrained eaters have conflicting goals,enjoyment of food versus dietary restraint.When strength of the enjoyment goal surpasses that of the dietary restraint goal,people are viewed as unsuccessful restrained eaters(van Strien&Ouwens,2007).Unsuccessful Restrained eaters are a high risk group for eating disorders and they have inhibitory control deficits compared to other people and are more likely to have eating behavior triggered when exposure to food environments and highly palatable food(Veenstra & Jong,2010;Polivy,& Herman,2003;Stirling& Yeomans,2004;Papies&Hamstra,2010;Stice,Presnell,Shaw,&Rohde,2005).Consequently,it is important to control their impulsive eating behaviors toward unhealthy foods.Currently,there are some experiments that target on normal people's impulsive eating behaviors and using the GO/NO-GO and stop signal task to improve participant's unhealthy eating behaviors,getting promising results(Houben,2011;Veling,Aarts,&Papies,2011,Jones,McGrath,Houben,Nederkoorn,Robinson,& Field,2014).But it doesn't have such interventions that focus on unsuccessful restrained eaters.Consequently,it is important to concentration onunsuccessful restrained eaters impulsive eating behaviors toward unhealthy foods.What's more,the underlying mechanism of these two interventions are not so clear.Previous study found that the attitude towards food mediate the effect of GO/NO-GO intervention(Veling,Aarts,&Stroebe,2013),but what about the stop signal task is dimness.So,in this research,unsuccessful Restrained eaters were identified and engaged in a stop signal task to reduce their approach tendencies toward unhealthy food and change their explicit and implicit attitudes toward unhealthy food.Then the mediation effects of implicit and explicit attitudes were tested.In the study1,we used the questionnaires to test the current situation of restrained eating in female university students.And found that almost 1/3 female students are restrained eaters;among these Restrained eaters,most of them are unsuccessful Restrained eaters;unsuccessful Restrained eaters have more unhealthy eating behaviors compared to normal and successful Restrained eaters.In the study 2,from an initial sample of 319 Chinese undergraduate women,we recruited 66 unsuccessful restrained eaters based on scoring cut-offs from the Three Factor Eating Questionnaire and Dutch Eating Behavior Questionnaire.Unhealthy food frequency questionnaire,Food ratings(liking and attractiveness rate toward health and unhealthy food)and Single Category Implicit Association Test were used as baseline tests for all the participants.Based on random assignment,33 women in the experimental condition engaged in inhibitory control training towards unhealthy food pictures)while 31 women in the control condition were provided with inhibitory control training towards non-food pictures).Each woman received seven 10-minute training sessions over one week.Finally,the participants completed a post-training assessment comprised of re-administered baseline measures and a food choice task.At baseline,self-reported weekly unhealthy food intake,food rating and implicit attitude towards unhealthy food did not differ between these two groups.Repeated MANOVA analyses,with group(intervention vs.control)and time(per-training vs.post-training)as independent variables,were conducted to assess changes in self-reported weekly unhealthy food intake.The significant Group ×Time interaction,(F(1,62)= 10.81,p < 0.01),indicated experimental group participants chose healthier food than control group in the food choice task.Experimental participants also had a reduction in reported liking and attractiveness of unhealthy foods between baseline and post-test compared with the control group.There were no changes in implicit attitudes towards unhealthy food in these two groups.As both groupsshowed an implicit preference for unhealthy foods both at baseline and post-intervention.In the study 3,before and after the intervention,participants' implicit attitude towards unhealthy food was measured,and then analyzedif subjects' implicit and explicit attitudes to unhealthy foodhave a mediation effect.Results show that both intervention and control groups have fairly strong implicitpreferences to unhealthy delicious foods at per-training and post-training;And both the implicit and explicit attitudesdidn'thavemediation effects.This is the first intervention experiment aimed to change unsuccessful restrained eaters' unhealthy food choice.These findings showed that there are many young woman in China are unsuccessful restrained eaters(29.15%)and inhibition control training can function even better in this group.But we do not found this intervention experiment change participants' implicit preference to unhealthy food and the mediation function of participants' implicit and explicit attitudes on this intervention.These findings indicate that it is effectiveness and possible to popularize this intervention to the whole society.