Does misperception of fruit and vegetable intake adequacy affect progression through the stages of behavior change after nutritional intervention?

Abstract

Pseudomaintenance (PM) is a Transtheoretical Model (TTM) stage of change that refers to individuals who believe they eat enough fruit and vegetables (FV) despite their low FV intake. It is not known how they change behavior after usual TTM-based interventions. Thus, this randomized controlled community trial describes the effect of PM on progression through the stages of change for FV intake among adult and elderly health promotion service users after TTM-based intervention. The stage of change for FV intake was assessed; FV intake was estimated from brief validated questions at baseline (n = 3414) and follow-up (n = 1782). Individuals whose perception of adequacy matched the estimated intake were labeled as “concordant perception,” while those with low intake who believed that their intake was adequate were classified as being in PM. The intervention group received the intervention while the control group received usual care. The prevalence of “no stage progression” at follow-up was close to 50% for those in PM at baseline. After adjustment for demographics, randomization, self-efficacy, decisional balance, and baseline intake, users in PM at baseline had higher odds [OR = 1.53 (1.21–1.94)] of progressing to higher stages for fruit and no difference in progression for vegetables. We propose strategies to approach FV intake in future studies and reinforce the need for additional trials aimed at describing changes in FV intake among individuals in PM, in order to continue answering the scientific questions that we began to investigate.

Introduction

Fruit and vegetable (FV) consumption promotes health (WHO & FAO, 2005) and lowers the risk of morbidity and premature mortality (Boeing et al., 2012); however, intake remains low worldwide. In Brazil, only 23.7% of adults report eating at least five servings a day (Brasil, 2019). In 2017, FV intake was found to be insufficient in almost all regions of the world, and diets low in fruit (less than 250g/day) and low in vegetables (less than 360g/day) were among the five leading dietary risk factors for morbidity and mortality (Afshin et al., 2019).

Different interventions for improving dietary habits have been proposed. The Transtheoretical Model (TTM) stands out as a promising tool for health promotion and nutrition education, including increases in FV intake (Menezes, Bedeschi, Santos, & Lopes, 2016). The TTM's main pillar is called stages of change, which represent an individual's readiness to modify a certain behavior (for example, to quit smoking or to increase fruit and vegetable intake) (J O Prochaska, Norcross, & DiClemente, 2013). The other pillars are called self-efficacy, decisional balance, and processes of change, which mediate the evolution through the stages of change (J. O. Prochaska & Velicer, 1997).

The five traditional stages of change are called pre-contemplation, contemplation, preparation, action, and maintenance. Individuals in pre-contemplation are not ready to change the target behavior. Those in contemplation are thinking about changing but feel ambivalent about the pros and cons of changing. Individuals in preparation have decided to start changing their behavior in the next 30 days. Those in action have sustained change for up to six months, while those in maintenance have been able to sustain the change for over six months (Prochaska, Diclemente, & Norcross, 1992).

Stages of change can be measured for a variety of health-related behaviors, such as dietary behavior (J O Prochaska et al., 2013). The identification of an individual's stage of change results from assessments based on individual perception of intake adequacy or estimated food intake (J O Prochaska et al., 2013; Toral & Slater, 2009). However, some individuals' perception of adequacy and objectively estimated intake might not match. Thus, two additional stages of change have been proposed: pseudomaintenance (PM), proposed by Steptoe et al. in 1996 (Steptoe, Wijetunge, Doherty, & Wardle, 1996) and non-reflective action (NRA), proposed by Ma et al. in 2003 (Ma, Betts, Horacek, Georgiou, & White, 2003). PM refers to individuals who have a low intake of these foods but believe they eat enough FV (Steptoe et al., 1996), while NRA refers to individuals who meet FV intake requirements but do not recognize their intake as sufficient (Ma et al., 2003).

To move from a stage of change to a more advanced stage, individuals change their self-efficacy and decisional balance (J. O. Prochaska & Velicer, 1997). Self-efficacy represents the extent to which individuals believe they are able to perform the behavior change, while decisional balance means the relative importance given to the pros and cons of changing (J. O. Prochaska & Velicer, 1997).

The existence of misperceived food intake has been reported in different contexts (Bedeschi, Lopes, & Santos, 2016; Carvalho, Menezes, & Lopes, 2018; Dijkstra, Neter, Brouwer, Huisman, & Visser, 2014; Figueira, Lopes, & Modena, 2015; Lechner, Brug, & De Vries, 1997; Lechner, Brug, De Vries, Van Assema, & Mudde, 1998; Ling & Horwath, 2000; Ma et al., 2003; Povey, Conner, Sparks, James, & Shepherd, 1998; Sproesser, Klusmann, Schupp, & Renner, 2015; Steptoe et al., 1996; Toral & Slater, 2009; Toral, Slater, Cintra, & Fisberg, 2006). However, few longitudinal or intervention studies have been done to identify whether and how misperception of FV intake affects the evolution of FV intake (Menezes, Mingoti, Mendonça, & Lopes, 2017; WHO, 2004). Most studies have a cross-sectional (Bedeschi et al., 2016; Carvalho et al., 2018; Dijkstra et al., 2014; Lechner et al., 1997, 1998; Ling & Horwath, 2000; Ma et al., 2003; Steptoe et al., 1996; Toral et al., 2006; Toral & Slater, 2009) or qualitative (Figueira et al., 2015; Povey et al., 1998) design. PM is the most prevalent type of discordant perception (Carvalho et al., 2018; Toral & Slater, 2009) and the one that poses the greatest risk for individuals, as they are exposed to low intake while believing that they eat enough FV; this can hinder their motivation to increase their intake. Furthermore, it is not known whether they can improve their perception of FV intake adequacy when they are exposed to interventions based on the five traditional stages.

Thus, this study aims to describe the effect of baseline pseudomaintenance on the evolution of the stages of change for FV intake in a sample of adult and elderly health promotion service users after a usual TTM-based nutritional intervention.