Appetite 83 (2014) 304–308
Contents lists available at ScienceDirect
Appetite j o u r n a l h o m e p a g e : w w w. e l s e v i e r. c o m / l o c a t e / a p p e t
Research report
A longitudinal study on the relationship between eating style and gestational weight gain ☆ Carla L. van der Wijden a,b,*,1, Stefanie Steinbach a,1, Hidde P. van der Ploeg a, Willem van Mechelen a, Mireille N.M. van Poppel a a b
Department of Public and Occupational Health, EMGO Institute for Health and Care Research, VU University Medical Center, Amsterdam, The Netherlands Department of Gynaecology, Medisch Centrum Jan van Goyen, Amsterdam, The Netherlands
A R T I C L E
I N F O
Article history: Received 28 April 2014 Received in revised form 2 September 2014 Accepted 5 September 2014 Available online 10 September 2014 Keywords: Eating style Gestational weight gain Self-efficacy and social norm
A B S T R A C T
Background: Gaining too much weight in pregnancy poses health risks for mother and child. Eating style has been shown to be related to weight gain in general but the relation to maternal weight gain in pregnancy is unclear. Objectives: To assess the influence of eating style and psycho social factors on maternal weight gain. Methods: Healthy pregnant women (n = 161), filled in a questionnaire at 15 and 35 weeks of pregnancy. Eating style, social norm, self-efficacy and attitude with regard to weight gain and health during pregnancy were measured. Self-reported pre-pregnancy body mass index (BMI) was used to determine weight category and weight was objectively measured at 15 and 35 weeks of gestation. Linear regression was used to study the relationship between eating style, psychosocial factors and gestational weight gain, controlling for BMI and age. Hierarchical regression analyses were carried out where the effects of the other eating styles were partialled out. Results: During pregnancy, 66% of the women remained stable as far as individual eating style concerned. At 15 weeks of gestation, 11 (7%) women were classified as emotional eaters, 89 (55%) as external eaters and 61 (38%) as restrained eaters. At first sight being an emotional eater was associated with higher weight gain in pregnancy. In hierarchical regression analyses however none of the eating styles was associated with higher gestational weight gain. Of the psychosocial factors, a better healthy pregnancy attitude at 35 weeks of gestation was associated with less weight gain. Discussion: In the long list of potential drivers of gestational weight gain, eating style does not seem to be of any significance. Healthy pregnancy attitude in late pregnancy was found to be related with less weight gain. © 2014 Elsevier Ltd. All rights reserved.
Introduction In the Western world, a beautiful woman is supposed to be a slender one. In reality most women are not slender and many women struggle with their body image and weight (Swami et al., 2010).
☆ Acknowledgements: We thank Prof Henriëtte A. Delemarre-van der Waal†, Department of Pediatrics, LUMC University Hospital Leiden for her critical remarks. Funding: This study was financially supported by a grant from the Netherlands Organization for Health Research and Development (ZonMw grant 4010.0017). Conflict of interest: None of the authors declare any conflict of interest. Contribution to authorship: SS, CvdW, MvP had a role in the designing and planning of the study. SS, HvdP and MvP performed the analyses and SS and CvdW drafted the article. HvdP, WvM and MvP critically appraised and revised the study results and manuscript. All authors approved this version of the manuscript. * Corresponding author. E-mail address: [email protected] (C.L. van der Wijden). 1 These authors contributed equally.
http://dx.doi.org/10.1016/j.appet.2014.09.001 0195-6663/© 2014 Elsevier Ltd. All rights reserved.
A woman’s eating style and associated habits might hamper her strive for a slender body. Eating style during pregnancy might even be more important, because maternal weight gain within a certain range creates the best chances for a healthy pregnancy and a healthy baby (Rasmussen, Catalano, & Yaktine, 2009). Gaining too much weight during pregnancy increases the risk for serious complications for the mother and the child during pregnancy and delivery. When the mother gains too much during pregnancy this might also lead to postpartum weight retention and this poses a risk to become overweight. Too much weight gain in the mother might lead to large for gestational age babies and a higher chance of childhood obesity. Gaining too little body weight might result in small for gestational age babies with a higher risk of obesity and hypertension (Calkins & Devaskar, 2011). Eating style is considered a stable trait (Kräuchi, Reich, & Wirz-Justice, 1997). In general, three types of eating styles can be identified: emotional eaters, external eaters, and restrained eaters
C.L. Wijden et al./Appetite 83 (2014) 304–308
and in most people, one of the three styles is more dominant (Van Strien, Schippers, & Cox, 1995). In emotional eaters food intake is triggered by emotion, with mainly negative emotion being associated with higher food intake (Kemp & Kopp, 2011; Timmerman & Acton, 2001). Emotional eating is said to be a learned behaviour and is negatively correlated with the level of basic need satisfaction (D’Arrigo, 2007). External eaters are stimulus bound in that their eating is triggered by cues in their environment (Van Strien, Schippers, & Cox, 1995). Their food intake is driven by food-related stimuli, such as parties or watching movies. Finally, restrained eaters restrict their dietary intake, or use other strategies for weight control to adhere to an ideal body image (Herman & Polivy, 1980; Elfhag & Morey, 2008; Anschutz, Van Strien, Van de Ven, & Engels, 2009). Although eating style outside of pregnancy is related to weight and weight gain, the role of eating style for weight gain in pregnancy is virtually unstudied. Therefore, the aim of the current paper is to assess this role in pregnancy among a population of healthy pregnant women. Methods For the purpose of this study, data were used from a randomized controlled trial on the New Life(style) intervention programme, which were collected between February 2005 and May 2006 (Althuizen, van Poppel, Seidell, van der Wijden, & van Mechelen, 2006) (ISRCTN85313483). The New Life(style) intervention consisted of five individual counselling sessions by one of the two trained counsellors with the specific aim to prevent excessive weight gain (Althuizen, van Poppel, Seidell, van der Wijden, & van Mechelen, 2006). Women were made aware that they could influence their weight gain through their eating behaviour as well as their level of physical activity, and were advised to gain weight according to the 1990 Institute of Medicine recommendations (Institute of Medicine (Subcommittees on Nutritional Status and Weight Gain During Pregnancy and Dietary Intake and Nutrient Supplements During Pregnancy, Committee on Nutritional Status During Pregnancy and Lactation, Food and Nutrition Board), 1990). Results of the intervention have been reported elsewhere, and in short, no effects of the intervention were found on any of the weight parameters in the total study group (Althuizen, van der Wijden, van Mechelen, Seidell, & van Poppel, 2013). The study was approved by the Medical Ethical Committee of the VU University Medical Centre, Amsterdam and all participants provided written informed consent.
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Body mass index Each woman’s pre-pregnancy body mass index (BMI) was calculated based on self-reported pre-pregnancy weight and objectively measured height. Based on their pre-pregnancy BMI, women were divided into three categories (underweight (BMI < 18.5), normal weight (BMI 18.5–25), and overweight or obese (BMI ≥ 25). Weight gain was defined as the objectively measured weight at 35 weeks of pregnancy minus the objectively measured weight at 15 weeks of pregnancy. Eating style Eating style and habits were assessed at 15 and 35 weeks of gestation by the Dutch version of the “Dutch Eating Behaviour Questionnaire (DEBQ)” (Van Strien et al., 1986). The DEBQ is a validated questionnaire and has a high test–retest reliability (Cronbach’s alpha 0.90 for emotional eating, 0.94 for restrained eating and 0.96 for external eating) (Bozan, Bas, & Asci, 2011). Based on the DEBQ, participants were classified as emotional, external or restrained eaters. Emotional eating was measured with 13 items; four items measuring diffuse emotions, and nine assessing specific emotions. External and restrained eating were measured by 10 items each. Women were classified to a specific eating style based on their DEBQ-score at 15 weeks of pregnancy, and again at 35 weeks to determine if they had changed. If their highest score was tied between two eating styles (n = 14) at either 15 or 35 weeks of pregnancy, the woman’s eating style at the other time point was taken into consideration when grouping her into an eating style. For one woman the score was tied between two eating styles at both time points.
Pregnant women from eight midwifery practices in The Netherlands were invited by the midwives to participate. Women were eligible if less than 14 weeks pregnant (first ongoing pregnancy) and fluent in Dutch. A total of 258 women were included. Exclusion criteria for the current analyses were if pre-pregnancy BMI or objectively measured pregnancy weight gain could not be established (n = 49), or if women had ≥2 items per scale missing in the DEBQ or ≥3 items per scale missing in the other questionnaires (n = 48).
Psychological factors Self-efficacy and attitude were assessed by scales constructed by Kendall, Olson, and Frongillo (2001), who drew items from existing validated scales. These scales were translated into Dutch (Kendall, Olson and Frongillo, 2001). The self-efficacy construct was measured with eight items on confidence about returning to pre-pregnancy weight and body shape, on the control of food intake, on confidence about getting regular exercise after pregnancy, and on food intake (Kendall, Olson and Frongillo, 2001). Attitude was split in “weight gain attitude” and “healthy pregnancy attitude”. The attitude women hold towards weight gain during pregnancy was assessed with a 13 item questionnaire (Kendall, Olson and Frongillo, 2001). Weight gain attitude was only measured at 15 weeks of gestation, and not at 35 weeks. “Healthy pregnancy attitude” describes the attitude of pregnant women towards regular exercise, a healthy diet, and healthy weight gain in favour of a healthy pregnancy. This was measured with nine items (e.g. how important do you find being physically active/eating healthy/gaining weight within recommendations). All questions were answered on a five point scale (e.g. very unimportant/unimportant/ neutral/important/very important) (Althuizen, van Poppel, Seidell, van der Wijden, & van Mechelen, 2006). Social norm, as described by assessing one’s belief that significant others e.g. spouse, family or friends want one to engage in a certain behaviour, was assessed with a nine item questionnaire (Althuizen, van Poppel, Seidell, van der Wijden, & van Mechelen, 2006; Symons Downs & Hausenblas, 2004).
Measurements
Statistical analyses
Participants received questionnaires for self completion by regular mail 1 week before their scheduled appointment at 15 and 35 weeks of pregnancy and were asked to hand in the filled in questionnaires during the subsequent appointment. On both occasions body height and body weight were measured objectively.
In a first analysis, women were classified according to their most dominant eating style and differences in weight gain. Subsequently, hierarchical linear regression analyses were performed, in which the scores on all three eating styles were included sequentially, thereby taking the interrelatedness of the eating styles into
Participants
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C.L. Wijden et al./Appetite 83 (2014) 304–308
Table 1 Description of participants. Eating style at 15 weeks
Age, years Prepregnancy BMI category, n (%) Underweight Healthy weight Overweight or obese Weight gain attitude at 15 weeks (range 1–5)a Healthy pregnancy attitude at 15 weeks (range 1–5)a Healthy pregnancy attitude at 35 weeks (range 1–5)a Self-efficacy at 15 weeks (range 1–5)a Self-efficacy at 35 weeks (range 1–5)a Subjective norm at 15 weeks (range 1–5)a Subjective norm at 35 weeks (range 1–5)a
Total (n = 161)
Emotional eaters (n = 11)
External eaters (n = 89)
Restrained eaters (n = 61)
Mean
Mean
Mean
Mean
29.4 14 102 38 3.4 3.9 3.6*** 4.1 4.2 3.2 3.1***
SD
SD
SD
3.9
28.6
4.5
28.6
4.1
9% 64% 27% 0.5 0.4 0.5 0.5 0.5 0.5 0.5
0 6 5 3.2 3.9 3.7 4.0 4.1 3.4 3.3
0% 55% 45% 0.5 0.4 0.4 0.3 0.5 0.5 0.6
13 54 21 3.4 3.8 3.5 4.1 4.1 3.2 3.0
15% 61% 24% 0.6 0.4 0.5 0.5 0.5 0.4 0.5
SD
30.7
3.3
1 42 17 3.4 4.0** 3.7** 4.2 4.3** 3.2 3.1
2% 70% 28% 0.4 0.4 0.4 0.5 0.5 0.5 0.5
a A higher score indicated a more positive attitude and subjective norm or a higher self-efficacy. ** Significant difference (p < 0.05) compared to external eaters. *** Significant difference (p < 0.05) compared to 15 weeks of gestation.
account. In the first step, BMI, age and the time between the two measurements of weight were entered (confounders), and in the second step, either external eating or emotional eating was added. In the third step, the other two eating styles were entered into the model. The improvement of the model (ΔR2) was assessed at each step. This way the entire range of information on the women’s eating style was used (Van Strien, Herman, & Verheijden, 2009). In a subsequent model, the role of a woman’s attitude, selfefficacy and social norm at 15 or 35 weeks on weight gain in pregnancy was assessed. All analyses were carried out in SPSS 20. Results A total of 161 women meeting the inclusion criteria were included in the analysis. The characteristics of these women are described in Table 1.
efficacy remained stable (Table 1). Women with a restrained eating style had a more positive healthy pregnancy attitude at both time points and higher self-efficacy at 35 weeks compared to external eaters (Table 1). Psychological factors of women with an emotional eating style were not different from those of women with an external eating style. Healthy pregnancy attitude was significantly correlated with an external (negatively) and restrained eating style (positively) (Table 2). Weight gain On average, women gained 11.3 kg (SD 3.7). Women with an emotional eating style at 15 weeks gained most (13.8 kg ± 4.1), followed by external eaters (11.4 kg ± 4.0). Restrained eaters gained least (10.8 kg ± 2.8). Weight gain in women with an emotional eating style was significantly higher compared to women with a restrained eating style (p < 0.05).
Eating style Associations with weight gain External eating style was the most prevalent style (53%), followed by restrained eating style (37%) at 15 weeks of gestation (Table 1). In Table 2, the correlations between the eating styles are presented and strong correlations between external eating and restrained eating were found, as well as significant correlations between emotional eating and external eating and between emotional eating and restrained eating. Psychological factors From early to late pregnancy, scores for social norm and selfefficacy decreased significantly in the total group, while self-
Because the three eating styles are highly interrelated, regression analyses were performed with the scores on all three eating styles included, adjusted for maternal age and BMI and the time between the two weight measurements. External eating (step 2) led to an increase in explained variance of weight gain, beyond that accounted for by BMI, age and the time between the two measurements. Adding emotional eating and restrained eating to the model (step 3) did not lead to significantly more explained variance (Table 3). When simultaneously entered into the model, no associations between the scores on eating styles at 15 or 35 weeks of gestation and weight gain were found (Table 3). Additional
Table 2 Correlations between eating styles and psychosocial factors at 15 weeks of pregnancy.
Emotional eating External eating Restrained eating Self-efficacy Social norm Weight gain attitude Health pregnancy attitude
Emotional eating
External eating
Restrained eating
Self-efficacy
Social norm
Weight gain attitude
Health pregnancy attitude
1 −0.30** −0.21** −0.04 0.09 −0.12 0.07
– 1 −0.87** −0.11 −0.04 0.07 −0.28**
– – 1 0.14 −0.002 −0.01 0.25**
– – – 1 0.18* 0.22** 0.33**
– – – – 1 −0.12 0.35**
– – – – – 1 −0.10
– – – – – – 1
Note: Bold formatting means significant correlations. * Pearson correlation coefficient significant at p < 0.05. ** Pearson correlation coefficient significant at p < 0.01.
C.L. Wijden et al./Appetite 83 (2014) 304–308
Table 3 Results of hierarchical linear regression analyses for the relationship between eating style and weight gain in pregnancy. Step
15 weeks of gestation 1 Time between measurements BMI Maternal age 2 External eating 3 Emotional eating Restrained eating 35 weeks of gestation 1 Time between measurements BMI Maternal age 2 External eating 3 Emotional eating Restrained eating
Weight gain between 15 and 35 weeks of gestation (kg) Beta
95% CI
0.41 0.13 −0.07
0.09; 0.73 −0.08; 0.34 −0.23; 0.09
1.41
−0.12; 2.94
−0.02 0.02
−1.03; 0.99 −0.93; 0.98
0.40 0.08 −0.06
0.08; 0.72 −0.13; 0.29 −0.22; 0.10
0.96
−0.53; 2.45
0.71 −0.07
−0.31; 1.74 −1.03; 0.89
ΔR2 0.07*
0.03* 0.00
0.07*
0.03* 0.01
Analyses were adjusted for the time between measurements, maternal age and BMI. * p < 0.05.
analyses showed that external eating was significantly associated with weight gain, when entered into the model without emotional and restrained eating (at 15 weeks; beta 1.39; 95% CI 0.08 to 2.71; p = 0.04 and at 35 weeks: beta 1.39; 95% CI 0.04 to 2.74; p = 0.04). Emotional eating at 35 weeks was significantly associated with weight gain (beta 0.97; 95% CI 0.06 to 1.89; p = 0.04) and led to more explained variance in weight gain, without external or restrained eating in the model. Emotional eating at 15 weeks and restrained eating at either time point were not significantly associated with weight gain, nor did this eating style lead to more explained variance, when entered into the model without the other two eating styles. This suggests that the overlapping variance in emotional and external eating at 35 weeks of gestation is significantly associated with weight gain. In a subsequent model, the psychological factors were added to the models. Only healthy pregnancy attitude at 35 weeks was associated with weight gain (β = −1. 83; 95% CI: −3.48, −0.18) indicating that a more positive attitude was related to less weight gain (Table 4). Discussion The main goal of this study was to identify the association between eating style and gestational weight gain. Therein, the influences of attitude, self-efficacy, and subjective norm were examined. At first sight we found that being an emotional eater was associated with more weight gain between 15 and 35 weeks of gestation, compared to being an external eater. This is in line with data outside pregnancy: people scoring high on emotional eating seem at risk for developing overweight, “because overconsumption seems to be more strongly related to weight gain in people with high degrees of emotional eating” (Van Strien, Herman, & Verheijden, 2009). However in the hierarchical regression models, we found that both emotional eating and external eating at 35 weeks significantly explained variance in weight gain. Then again with all three eating styles together in one model, no effect association between any eating styles with gestational weight gain was found.
307
In two previous studies an association between restrained eating and weight gain in pregnancy was found (Van Strien, Herman, & Verheijden, 2009; Mumford, Siega-Riz, Herring, & Evenson, 2008) but in another study no effect of restrained eating on weight gain was found (Clark & Ogden, 1999). In these studies the interrelatedness of the three eating styles was not taken into account, therefore comparisons are difficult to make. In our study, psychological factors, such as attitude, selfefficacy and social norm were not found to be important factors for weight gain after taking eating style into account. This is perhaps not surprising, since we did not relate these factors to specific behavioural outcomes, but to weight gain (Kendall et al., 2001; Olson & Strawderman, 2003; Clark, Skouteris, Wertheim, Paxton, & Milgrom, 2009). Only a healthy pregnancy attitude in late pregnancy was related to less weight gain. A healthy pregnancy attitude describes the attitude of pregnant women towards regular exercise, a healthy diet, and healthy weight gain in favour of a healthy pregnancy, and a higher score might go along with a higher motivation to manage weight gain according to recommendations (Althuizen, van Poppel, Seidell, van der Wijden, & van Mechelen, 2006). Limitations of this study were the small numbers, especially of overweight or obese women. In a population with more overweight and obese women, perhaps a larger proportion of emotional eaters can be expected and a different pattern of interrelationships. Confirming our findings in a sample of more overweight pregnant women would be useful. In this study, factors such as nausea, vomiting or heartburn, were not taken into account. Considering that these factors could also influence eating behaviour and weight gain, it is important to notice that in this study they were not controlled for, even though 95% of pregnant women do experience some nausea or vomiting and/or heartburn (Naumann, Zelig, Napolitano & Ko, 2012). On the basis of these data it can be concluded that, in the long list of potential drivers of gestational weight gain e.g. physical activity and dietary intake (Thangaratinam, Rogozinska, Jolly, Glinkowski, et al. 2012), eating style might be of limited significance in influencing gestational weight gain. The influence of healthy pregnancy attitude needs to be explored further.
Table 4 The relationship between eating style, psychosocial variables and weight gain in pregnancy. Weight gain between 15 and 35 weeks of gestation (kg)
15 weeks of gestation Eating style at 15 weeks External eating Emotional eating Restrained eating Weight gain attitude 15 weeks (range 1–5) Healthy pregnancy attitude 15 weeks (range 1–5) Self-efficacy 15 weeks (range 1–5) Subjective norm 15 weeks (range 1–5) 35 weeks of gestation Eating style at 35 weeks External eating Emotional eating Restrained eating Weight gain attitude 15 weeks (range 1–5) Healthy pregnancy attitude 35 weeks (range 1–5) Self-efficacy 35 weeks (range 1–5) Subjective norm 35 weeks (range 1–5)
Betaa
95% CI
1.53 0.22 0.09 0.36 −0.80
−0.01; 3.07 −0.83; 1.25 −0.91; 1.08 −0.90; 1.62 −2.37; 0.77
1.25 −0.51
−0.08; 2.59 −1.90; 0.88
0.47 0.82 0.26 0.30 −1.83
−1.08; 2.02 −0.23; 1.88 −0.75; 1.27 −1.00; 1.60 −3.48; −0.18
0.19 0.55
−1.16; 1.54 −0.81; 1.90
a Analyses were adjusted for the time between measurements, maternal age and BMI.
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Contents lists available at ScienceDirect
Appetite j o u r n a l h o m e p a g e : w w w. e l s e v i e r. c o m / l o c a t e / a p p e t
Research report
A longitudinal study on the relationship between eating style and gestational weight gain ☆ Carla L. van der Wijden a,b,*,1, Stefanie Steinbach a,1, Hidde P. van der Ploeg a, Willem van Mechelen a, Mireille N.M. van Poppel a a b
Department of Public and Occupational Health, EMGO Institute for Health and Care Research, VU University Medical Center, Amsterdam, The Netherlands Department of Gynaecology, Medisch Centrum Jan van Goyen, Amsterdam, The Netherlands
A R T I C L E
I N F O
Article history: Received 28 April 2014 Received in revised form 2 September 2014 Accepted 5 September 2014 Available online 10 September 2014 Keywords: Eating style Gestational weight gain Self-efficacy and social norm
A B S T R A C T
Background: Gaining too much weight in pregnancy poses health risks for mother and child. Eating style has been shown to be related to weight gain in general but the relation to maternal weight gain in pregnancy is unclear. Objectives: To assess the influence of eating style and psycho social factors on maternal weight gain. Methods: Healthy pregnant women (n = 161), filled in a questionnaire at 15 and 35 weeks of pregnancy. Eating style, social norm, self-efficacy and attitude with regard to weight gain and health during pregnancy were measured. Self-reported pre-pregnancy body mass index (BMI) was used to determine weight category and weight was objectively measured at 15 and 35 weeks of gestation. Linear regression was used to study the relationship between eating style, psychosocial factors and gestational weight gain, controlling for BMI and age. Hierarchical regression analyses were carried out where the effects of the other eating styles were partialled out. Results: During pregnancy, 66% of the women remained stable as far as individual eating style concerned. At 15 weeks of gestation, 11 (7%) women were classified as emotional eaters, 89 (55%) as external eaters and 61 (38%) as restrained eaters. At first sight being an emotional eater was associated with higher weight gain in pregnancy. In hierarchical regression analyses however none of the eating styles was associated with higher gestational weight gain. Of the psychosocial factors, a better healthy pregnancy attitude at 35 weeks of gestation was associated with less weight gain. Discussion: In the long list of potential drivers of gestational weight gain, eating style does not seem to be of any significance. Healthy pregnancy attitude in late pregnancy was found to be related with less weight gain. © 2014 Elsevier Ltd. All rights reserved.
Introduction In the Western world, a beautiful woman is supposed to be a slender one. In reality most women are not slender and many women struggle with their body image and weight (Swami et al., 2010).
☆ Acknowledgements: We thank Prof Henriëtte A. Delemarre-van der Waal†, Department of Pediatrics, LUMC University Hospital Leiden for her critical remarks. Funding: This study was financially supported by a grant from the Netherlands Organization for Health Research and Development (ZonMw grant 4010.0017). Conflict of interest: None of the authors declare any conflict of interest. Contribution to authorship: SS, CvdW, MvP had a role in the designing and planning of the study. SS, HvdP and MvP performed the analyses and SS and CvdW drafted the article. HvdP, WvM and MvP critically appraised and revised the study results and manuscript. All authors approved this version of the manuscript. * Corresponding author. E-mail address: [email protected] (C.L. van der Wijden). 1 These authors contributed equally.
http://dx.doi.org/10.1016/j.appet.2014.09.001 0195-6663/© 2014 Elsevier Ltd. All rights reserved.
A woman’s eating style and associated habits might hamper her strive for a slender body. Eating style during pregnancy might even be more important, because maternal weight gain within a certain range creates the best chances for a healthy pregnancy and a healthy baby (Rasmussen, Catalano, & Yaktine, 2009). Gaining too much weight during pregnancy increases the risk for serious complications for the mother and the child during pregnancy and delivery. When the mother gains too much during pregnancy this might also lead to postpartum weight retention and this poses a risk to become overweight. Too much weight gain in the mother might lead to large for gestational age babies and a higher chance of childhood obesity. Gaining too little body weight might result in small for gestational age babies with a higher risk of obesity and hypertension (Calkins & Devaskar, 2011). Eating style is considered a stable trait (Kräuchi, Reich, & Wirz-Justice, 1997). In general, three types of eating styles can be identified: emotional eaters, external eaters, and restrained eaters
C.L. Wijden et al./Appetite 83 (2014) 304–308
and in most people, one of the three styles is more dominant (Van Strien, Schippers, & Cox, 1995). In emotional eaters food intake is triggered by emotion, with mainly negative emotion being associated with higher food intake (Kemp & Kopp, 2011; Timmerman & Acton, 2001). Emotional eating is said to be a learned behaviour and is negatively correlated with the level of basic need satisfaction (D’Arrigo, 2007). External eaters are stimulus bound in that their eating is triggered by cues in their environment (Van Strien, Schippers, & Cox, 1995). Their food intake is driven by food-related stimuli, such as parties or watching movies. Finally, restrained eaters restrict their dietary intake, or use other strategies for weight control to adhere to an ideal body image (Herman & Polivy, 1980; Elfhag & Morey, 2008; Anschutz, Van Strien, Van de Ven, & Engels, 2009). Although eating style outside of pregnancy is related to weight and weight gain, the role of eating style for weight gain in pregnancy is virtually unstudied. Therefore, the aim of the current paper is to assess this role in pregnancy among a population of healthy pregnant women. Methods For the purpose of this study, data were used from a randomized controlled trial on the New Life(style) intervention programme, which were collected between February 2005 and May 2006 (Althuizen, van Poppel, Seidell, van der Wijden, & van Mechelen, 2006) (ISRCTN85313483). The New Life(style) intervention consisted of five individual counselling sessions by one of the two trained counsellors with the specific aim to prevent excessive weight gain (Althuizen, van Poppel, Seidell, van der Wijden, & van Mechelen, 2006). Women were made aware that they could influence their weight gain through their eating behaviour as well as their level of physical activity, and were advised to gain weight according to the 1990 Institute of Medicine recommendations (Institute of Medicine (Subcommittees on Nutritional Status and Weight Gain During Pregnancy and Dietary Intake and Nutrient Supplements During Pregnancy, Committee on Nutritional Status During Pregnancy and Lactation, Food and Nutrition Board), 1990). Results of the intervention have been reported elsewhere, and in short, no effects of the intervention were found on any of the weight parameters in the total study group (Althuizen, van der Wijden, van Mechelen, Seidell, & van Poppel, 2013). The study was approved by the Medical Ethical Committee of the VU University Medical Centre, Amsterdam and all participants provided written informed consent.
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Body mass index Each woman’s pre-pregnancy body mass index (BMI) was calculated based on self-reported pre-pregnancy weight and objectively measured height. Based on their pre-pregnancy BMI, women were divided into three categories (underweight (BMI < 18.5), normal weight (BMI 18.5–25), and overweight or obese (BMI ≥ 25). Weight gain was defined as the objectively measured weight at 35 weeks of pregnancy minus the objectively measured weight at 15 weeks of pregnancy. Eating style Eating style and habits were assessed at 15 and 35 weeks of gestation by the Dutch version of the “Dutch Eating Behaviour Questionnaire (DEBQ)” (Van Strien et al., 1986). The DEBQ is a validated questionnaire and has a high test–retest reliability (Cronbach’s alpha 0.90 for emotional eating, 0.94 for restrained eating and 0.96 for external eating) (Bozan, Bas, & Asci, 2011). Based on the DEBQ, participants were classified as emotional, external or restrained eaters. Emotional eating was measured with 13 items; four items measuring diffuse emotions, and nine assessing specific emotions. External and restrained eating were measured by 10 items each. Women were classified to a specific eating style based on their DEBQ-score at 15 weeks of pregnancy, and again at 35 weeks to determine if they had changed. If their highest score was tied between two eating styles (n = 14) at either 15 or 35 weeks of pregnancy, the woman’s eating style at the other time point was taken into consideration when grouping her into an eating style. For one woman the score was tied between two eating styles at both time points.
Pregnant women from eight midwifery practices in The Netherlands were invited by the midwives to participate. Women were eligible if less than 14 weeks pregnant (first ongoing pregnancy) and fluent in Dutch. A total of 258 women were included. Exclusion criteria for the current analyses were if pre-pregnancy BMI or objectively measured pregnancy weight gain could not be established (n = 49), or if women had ≥2 items per scale missing in the DEBQ or ≥3 items per scale missing in the other questionnaires (n = 48).
Psychological factors Self-efficacy and attitude were assessed by scales constructed by Kendall, Olson, and Frongillo (2001), who drew items from existing validated scales. These scales were translated into Dutch (Kendall, Olson and Frongillo, 2001). The self-efficacy construct was measured with eight items on confidence about returning to pre-pregnancy weight and body shape, on the control of food intake, on confidence about getting regular exercise after pregnancy, and on food intake (Kendall, Olson and Frongillo, 2001). Attitude was split in “weight gain attitude” and “healthy pregnancy attitude”. The attitude women hold towards weight gain during pregnancy was assessed with a 13 item questionnaire (Kendall, Olson and Frongillo, 2001). Weight gain attitude was only measured at 15 weeks of gestation, and not at 35 weeks. “Healthy pregnancy attitude” describes the attitude of pregnant women towards regular exercise, a healthy diet, and healthy weight gain in favour of a healthy pregnancy. This was measured with nine items (e.g. how important do you find being physically active/eating healthy/gaining weight within recommendations). All questions were answered on a five point scale (e.g. very unimportant/unimportant/ neutral/important/very important) (Althuizen, van Poppel, Seidell, van der Wijden, & van Mechelen, 2006). Social norm, as described by assessing one’s belief that significant others e.g. spouse, family or friends want one to engage in a certain behaviour, was assessed with a nine item questionnaire (Althuizen, van Poppel, Seidell, van der Wijden, & van Mechelen, 2006; Symons Downs & Hausenblas, 2004).
Measurements
Statistical analyses
Participants received questionnaires for self completion by regular mail 1 week before their scheduled appointment at 15 and 35 weeks of pregnancy and were asked to hand in the filled in questionnaires during the subsequent appointment. On both occasions body height and body weight were measured objectively.
In a first analysis, women were classified according to their most dominant eating style and differences in weight gain. Subsequently, hierarchical linear regression analyses were performed, in which the scores on all three eating styles were included sequentially, thereby taking the interrelatedness of the eating styles into
Participants
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Table 1 Description of participants. Eating style at 15 weeks
Age, years Prepregnancy BMI category, n (%) Underweight Healthy weight Overweight or obese Weight gain attitude at 15 weeks (range 1–5)a Healthy pregnancy attitude at 15 weeks (range 1–5)a Healthy pregnancy attitude at 35 weeks (range 1–5)a Self-efficacy at 15 weeks (range 1–5)a Self-efficacy at 35 weeks (range 1–5)a Subjective norm at 15 weeks (range 1–5)a Subjective norm at 35 weeks (range 1–5)a
Total (n = 161)
Emotional eaters (n = 11)
External eaters (n = 89)
Restrained eaters (n = 61)
Mean
Mean
Mean
Mean
29.4 14 102 38 3.4 3.9 3.6*** 4.1 4.2 3.2 3.1***
SD
SD
SD
3.9
28.6
4.5
28.6
4.1
9% 64% 27% 0.5 0.4 0.5 0.5 0.5 0.5 0.5
0 6 5 3.2 3.9 3.7 4.0 4.1 3.4 3.3
0% 55% 45% 0.5 0.4 0.4 0.3 0.5 0.5 0.6
13 54 21 3.4 3.8 3.5 4.1 4.1 3.2 3.0
15% 61% 24% 0.6 0.4 0.5 0.5 0.5 0.4 0.5
SD
30.7
3.3
1 42 17 3.4 4.0** 3.7** 4.2 4.3** 3.2 3.1
2% 70% 28% 0.4 0.4 0.4 0.5 0.5 0.5 0.5
a A higher score indicated a more positive attitude and subjective norm or a higher self-efficacy. ** Significant difference (p < 0.05) compared to external eaters. *** Significant difference (p < 0.05) compared to 15 weeks of gestation.
account. In the first step, BMI, age and the time between the two measurements of weight were entered (confounders), and in the second step, either external eating or emotional eating was added. In the third step, the other two eating styles were entered into the model. The improvement of the model (ΔR2) was assessed at each step. This way the entire range of information on the women’s eating style was used (Van Strien, Herman, & Verheijden, 2009). In a subsequent model, the role of a woman’s attitude, selfefficacy and social norm at 15 or 35 weeks on weight gain in pregnancy was assessed. All analyses were carried out in SPSS 20. Results A total of 161 women meeting the inclusion criteria were included in the analysis. The characteristics of these women are described in Table 1.
efficacy remained stable (Table 1). Women with a restrained eating style had a more positive healthy pregnancy attitude at both time points and higher self-efficacy at 35 weeks compared to external eaters (Table 1). Psychological factors of women with an emotional eating style were not different from those of women with an external eating style. Healthy pregnancy attitude was significantly correlated with an external (negatively) and restrained eating style (positively) (Table 2). Weight gain On average, women gained 11.3 kg (SD 3.7). Women with an emotional eating style at 15 weeks gained most (13.8 kg ± 4.1), followed by external eaters (11.4 kg ± 4.0). Restrained eaters gained least (10.8 kg ± 2.8). Weight gain in women with an emotional eating style was significantly higher compared to women with a restrained eating style (p < 0.05).
Eating style Associations with weight gain External eating style was the most prevalent style (53%), followed by restrained eating style (37%) at 15 weeks of gestation (Table 1). In Table 2, the correlations between the eating styles are presented and strong correlations between external eating and restrained eating were found, as well as significant correlations between emotional eating and external eating and between emotional eating and restrained eating. Psychological factors From early to late pregnancy, scores for social norm and selfefficacy decreased significantly in the total group, while self-
Because the three eating styles are highly interrelated, regression analyses were performed with the scores on all three eating styles included, adjusted for maternal age and BMI and the time between the two weight measurements. External eating (step 2) led to an increase in explained variance of weight gain, beyond that accounted for by BMI, age and the time between the two measurements. Adding emotional eating and restrained eating to the model (step 3) did not lead to significantly more explained variance (Table 3). When simultaneously entered into the model, no associations between the scores on eating styles at 15 or 35 weeks of gestation and weight gain were found (Table 3). Additional
Table 2 Correlations between eating styles and psychosocial factors at 15 weeks of pregnancy.
Emotional eating External eating Restrained eating Self-efficacy Social norm Weight gain attitude Health pregnancy attitude
Emotional eating
External eating
Restrained eating
Self-efficacy
Social norm
Weight gain attitude
Health pregnancy attitude
1 −0.30** −0.21** −0.04 0.09 −0.12 0.07
– 1 −0.87** −0.11 −0.04 0.07 −0.28**
– – 1 0.14 −0.002 −0.01 0.25**
– – – 1 0.18* 0.22** 0.33**
– – – – 1 −0.12 0.35**
– – – – – 1 −0.10
– – – – – – 1
Note: Bold formatting means significant correlations. * Pearson correlation coefficient significant at p < 0.05. ** Pearson correlation coefficient significant at p < 0.01.
C.L. Wijden et al./Appetite 83 (2014) 304–308
Table 3 Results of hierarchical linear regression analyses for the relationship between eating style and weight gain in pregnancy. Step
15 weeks of gestation 1 Time between measurements BMI Maternal age 2 External eating 3 Emotional eating Restrained eating 35 weeks of gestation 1 Time between measurements BMI Maternal age 2 External eating 3 Emotional eating Restrained eating
Weight gain between 15 and 35 weeks of gestation (kg) Beta
95% CI
0.41 0.13 −0.07
0.09; 0.73 −0.08; 0.34 −0.23; 0.09
1.41
−0.12; 2.94
−0.02 0.02
−1.03; 0.99 −0.93; 0.98
0.40 0.08 −0.06
0.08; 0.72 −0.13; 0.29 −0.22; 0.10
0.96
−0.53; 2.45
0.71 −0.07
−0.31; 1.74 −1.03; 0.89
ΔR2 0.07*
0.03* 0.00
0.07*
0.03* 0.01
Analyses were adjusted for the time between measurements, maternal age and BMI. * p < 0.05.
analyses showed that external eating was significantly associated with weight gain, when entered into the model without emotional and restrained eating (at 15 weeks; beta 1.39; 95% CI 0.08 to 2.71; p = 0.04 and at 35 weeks: beta 1.39; 95% CI 0.04 to 2.74; p = 0.04). Emotional eating at 35 weeks was significantly associated with weight gain (beta 0.97; 95% CI 0.06 to 1.89; p = 0.04) and led to more explained variance in weight gain, without external or restrained eating in the model. Emotional eating at 15 weeks and restrained eating at either time point were not significantly associated with weight gain, nor did this eating style lead to more explained variance, when entered into the model without the other two eating styles. This suggests that the overlapping variance in emotional and external eating at 35 weeks of gestation is significantly associated with weight gain. In a subsequent model, the psychological factors were added to the models. Only healthy pregnancy attitude at 35 weeks was associated with weight gain (β = −1. 83; 95% CI: −3.48, −0.18) indicating that a more positive attitude was related to less weight gain (Table 4). Discussion The main goal of this study was to identify the association between eating style and gestational weight gain. Therein, the influences of attitude, self-efficacy, and subjective norm were examined. At first sight we found that being an emotional eater was associated with more weight gain between 15 and 35 weeks of gestation, compared to being an external eater. This is in line with data outside pregnancy: people scoring high on emotional eating seem at risk for developing overweight, “because overconsumption seems to be more strongly related to weight gain in people with high degrees of emotional eating” (Van Strien, Herman, & Verheijden, 2009). However in the hierarchical regression models, we found that both emotional eating and external eating at 35 weeks significantly explained variance in weight gain. Then again with all three eating styles together in one model, no effect association between any eating styles with gestational weight gain was found.
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In two previous studies an association between restrained eating and weight gain in pregnancy was found (Van Strien, Herman, & Verheijden, 2009; Mumford, Siega-Riz, Herring, & Evenson, 2008) but in another study no effect of restrained eating on weight gain was found (Clark & Ogden, 1999). In these studies the interrelatedness of the three eating styles was not taken into account, therefore comparisons are difficult to make. In our study, psychological factors, such as attitude, selfefficacy and social norm were not found to be important factors for weight gain after taking eating style into account. This is perhaps not surprising, since we did not relate these factors to specific behavioural outcomes, but to weight gain (Kendall et al., 2001; Olson & Strawderman, 2003; Clark, Skouteris, Wertheim, Paxton, & Milgrom, 2009). Only a healthy pregnancy attitude in late pregnancy was related to less weight gain. A healthy pregnancy attitude describes the attitude of pregnant women towards regular exercise, a healthy diet, and healthy weight gain in favour of a healthy pregnancy, and a higher score might go along with a higher motivation to manage weight gain according to recommendations (Althuizen, van Poppel, Seidell, van der Wijden, & van Mechelen, 2006). Limitations of this study were the small numbers, especially of overweight or obese women. In a population with more overweight and obese women, perhaps a larger proportion of emotional eaters can be expected and a different pattern of interrelationships. Confirming our findings in a sample of more overweight pregnant women would be useful. In this study, factors such as nausea, vomiting or heartburn, were not taken into account. Considering that these factors could also influence eating behaviour and weight gain, it is important to notice that in this study they were not controlled for, even though 95% of pregnant women do experience some nausea or vomiting and/or heartburn (Naumann, Zelig, Napolitano & Ko, 2012). On the basis of these data it can be concluded that, in the long list of potential drivers of gestational weight gain e.g. physical activity and dietary intake (Thangaratinam, Rogozinska, Jolly, Glinkowski, et al. 2012), eating style might be of limited significance in influencing gestational weight gain. The influence of healthy pregnancy attitude needs to be explored further.
Table 4 The relationship between eating style, psychosocial variables and weight gain in pregnancy. Weight gain between 15 and 35 weeks of gestation (kg)
15 weeks of gestation Eating style at 15 weeks External eating Emotional eating Restrained eating Weight gain attitude 15 weeks (range 1–5) Healthy pregnancy attitude 15 weeks (range 1–5) Self-efficacy 15 weeks (range 1–5) Subjective norm 15 weeks (range 1–5) 35 weeks of gestation Eating style at 35 weeks External eating Emotional eating Restrained eating Weight gain attitude 15 weeks (range 1–5) Healthy pregnancy attitude 35 weeks (range 1–5) Self-efficacy 35 weeks (range 1–5) Subjective norm 35 weeks (range 1–5)
Betaa
95% CI
1.53 0.22 0.09 0.36 −0.80
−0.01; 3.07 −0.83; 1.25 −0.91; 1.08 −0.90; 1.62 −2.37; 0.77
1.25 −0.51
−0.08; 2.59 −1.90; 0.88
0.47 0.82 0.26 0.30 −1.83
−1.08; 2.02 −0.23; 1.88 −0.75; 1.27 −1.00; 1.60 −3.48; −0.18
0.19 0.55
−1.16; 1.54 −0.81; 1.90
a Analyses were adjusted for the time between measurements, maternal age and BMI.
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