تغذیه بی فکر: آیا حواس پرتی مادر در تغذیه با شیشه شیر مرتبط با تغذیه بیش از حد است؟

Abstract Mindless eating, or eating while distracted by surrounding stimuli, leads to overeating. The present study explored whether “mindless feeding,” or maternal distraction during bottle-feeding, is associated with greater infant formula/milk intakes and lower maternal sensitivity to infant cues. Mothers and their ≤24-week-old bottle-feeding infants (N = 28) visited our laboratory for a video-recorded feeding observation. Infant intake was assessed by weighing bottles before and after the feedings. Maternal sensitivity to infant cues was objectively assessed by behavioral coding of video-records using the Nursing Child Assessment Feeding Scale. Maternal distraction was defined as looking away from the infant >75% of the feeding; using a mobile device; conversing with another adult; or sleeping. Twenty-nine percent (n = 8) of mothers were distracted. While differences in intakes for infants of distracted vs. not distracted mothers did not reach significance (p = 0.24), the association between distraction and infant intake was modified by two dimensions of temperament: orienting/regulation capacity (p = 0.03) and surgency/extraversion (p = 0.04). For infants with low orienting/regulation capacity, infants of distracted mothers consumed more (177.1 ± 33.8 ml) than those of not distracted mothers (92.4 ± 13.8 ml). Similar findings were noted for infants with low surgency/extraversion (distracted: 140.6 ± 22.5 ml; not distracted: 78.4 ± 14.3 ml). No association between distraction and intake was seen for infants with high orienting/regulation capacity or surgency/extraversion. A significantly greater proportion of distracted mothers showed low sensitivity to infant cues compared to not distracted mothers (p = 0.04). In sum, mindless feeding may interact with infant characteristics to influence feeding outcomes; further experimental and longitudinal studies are needed.

Introduction Rates of childhood overweight and obesity have stabilized and even declined for certain age groups over the past decade (Ogden, Carroll, Kit, & Flegal, 2014). Despite these promising trends, the prevalence of overweight and obesity remains well above national health targets (U.S. Department of Health and Human Services: Office of Disease Prevention and Health Promotion, and U.S. Department of Health and Human Services: Office of Disease Prevention and Health Promotion,) as 32% of youth are either overweight or obese, and 17% are obese (Ogden et al., 2014). Additionally, over 7% of infants are classified as having a high weight-for-recumbent length (Ogden et al., 2014). Overweight and obesity track across the life-course (Baird et al., 2005), and infancy, in particular, has been highlighted as a critical period for determining later chronic disease risk (Institute of Medicine, 2011). These data suggest that evidence-based obesity prevention strategies are still relevant and should be focused on during the first few years of life. One of the earliest postnatal risk factors is rapid weight gain during infancy (Druet et al., 2012), which is a strong predictor of later obesity (Dennison, Edmunds, Stratton, & Pruzek, 2006); higher blood pressure, fasting glucose levels, and fasting triglyceride concentrations and lower high density lipoprotein (HDL) cholesterol levels (Ekelund et al., 2007); higher waist circumference (Sacco, de Castro, Euclydes, Souza, & Rondo, 2013), and non-alcoholic fatty liver disease (Breij, Kerkhof, & Hokken-Koelega, 2014). Given that infants are primarily dependent on their caregivers, and most often their mothers (Demaris et al, 2013 and Nystrom, Ohrling, 2004), to determine when, where, what, and sometimes even how much, will be consumed, consideration of mother–infant interactions and the impact of mothers' feeding practices on infant feeding and weight status outcomes is a logical starting point for understanding predictors of rapid weight gain during infancy. A recent Institute of Medicine (IOM) report outlines several recommendations for reducing risk for rapid weight gain during infancy, one of which encourages measures to help caregivers recognize and feed in response to infant hunger and fullness cues, especially during bottle-feeding (Institute of Medicine, 2011). Indeed, previous studies have suggested that mothers with lower responsiveness to infant cues have infants with greater weight gain across infancy (Blissett, Farrow, 2007, Farrow, Blissett, 2006, Farrow, Blissett, 2008 and Worobey et al, 2009), but few studies have examined predictors of low maternal responsiveness (Brown & Lee, 2011) or have directly assessed the impact of mothers' lack of responsiveness on infant intake and weight gain trajectories (DiSantis, Hodges, Johnson, & Fisher, 2011). Thus, our current understanding of how to promote responsive feeding practices during infant-feeding interactions is limited. Although there may be many reasons for why a mother would feed in a way that is not responsive to an infant's cues (Brown, Lee, 2013, Brown et al, 2011 and Stifter et al, 2011), one reason that, to our knowledge, has not been explored is the possibility that maternal distraction, or the tendency of the mother to pay attention to stimuli other than her infant during feeding interactions, impairs mothers' abilities to recognize and feed in response to infants' hunger and fullness cues. A substantial body of research illustrates that older children and adults who engage in “mindless eating,” or eating while distracted, tend to consume more food than those who concentrate solely on their food (Wansink, 2006). Individuals who are distracted by other tasks, computers, television, work, or driving (Wansink, 2006), tend to rely on external cues to dictate when they should stop eating (e.g., when the episode of a TV show they are watching ends), rather than on their internal cues of hunger and fullness (Wansink, Payne, & Chandon, 2007). They also tend to report feeling less satiated than non-distracted individuals after eating the same amount of food (Brunstrom & Mitchell, 2006), and thus continue to eat in the absence of hunger (McKetta, Rich, 2011 and Wansink et al, 2007). As follows, it is possible that caregivers who engage in “mindless feeding,” or who are distracted while feeding their infants, would be less sensitive to their infants' cues and at higher risk for overfeeding. It is also possible, however, that certain infants would be more impacted by a lack of maternal attention during feeding than others, as previous research has highlighted several factors that increase risk for overfeeding. For example, satiety responsiveness declines with age, which may be due to learned tendencies to overeat (Birch et al, 2003 and Jansen, 1998). Furthermore, infants with certain temperament characteristics, such as higher negativity (Anzman-Frasca et al, 2012 and Slining et al, 2009), surgency/extraversion [a precursor to later impulsivity (Burton et al, 2011 and Rothbart et al, 2001)], or lower orienting/regulation capacity [an early manifestation of poor self-regulation skills (Francis, Susman, 2009, Graziano et al, 2010, Tan, Holub, 2011 and Wells et al, 1997)], are at higher risk for rapid weight gain and later obesity, which may be due, in part, to poor self-regulatory abilities. Thus, it is possible that caregiver attention to infant feeding behaviors may be especially critical to ensure these infants do not over-feed. The objective of the present study was to assess the association between maternal distraction during infant feeding interactions and feeding outcomes. The first aim of this study was to explore: 1) whether mothers who were distracted while feeding their infants would feed their infants more formula or milk than mothers who were not distracted, and 2) whether infant characteristics (e.g., age or temperament) would moderate the association between distraction and infant intake. The second aim of this study was to assess whether mothers who were distracted would show lower levels of sensitivity to their infants' cues compared to mothers who were not distracted.

Results Sample characteristics Sample characteristics are presented in Table 1. Sixty percent of infants were female. Infants had a mean age of 2.8 ± 1.7 months (11.2 ± 6.8 weeks) upon study entry, with a mean weight-for-length percentile of 75.2 ± 24.8 and weight-for-length z-score of 2.1 ± 0.7. The majority of infants consumed partial protein-hydrolysate formula (pPHF; 43%, n = 12). Lesser proportions of infants consumed cow's milk formula (CMF; 25%), soy-protein formula (SPF; 21%), and breast milk (11%). The average age of mothers was 26.9 ± 6.9 years and pre-pregnancy BMI was 31.7 ± 6.2. The majority of mothers (91.7%) received federal assistance (e.g., WIC benefits) and 60.7% had a family income of <$15,000 per year. The percentage of mothers with no college education or vocational degree was 60.7%. Seventy-six percent of mothers were non-Hispanic Black, and 75% were not married. The majority of mothers had three or fewer children (one child: 28%, two children: 28%, three children: 16%). Table 1. Percent (n) or mean ± SD values for sample characteristics (N = 28). Infant characteristics:  Sex, % female 60.0 (15)  Age at study entry, months 2.8 ± 1.7  Birth weight-for-length percentile 39.0 ± 39.4  Weight-for-length percentile at study entry 75.2 ± 24.8  Type of milk/formula consumed during study   Breast milk 11 (3)   pPHF 43 (12)   SPF 21 (6)   CMF 25 (7) Maternal/familial characteristics:  Age, years 26.9 ± 6.9  Pre-pregnancy BMI, kg/m2 31.2 ± 8.3  Received federal assistance (WIC) 91.7 (22)  Family income, % < $15,000/year 60.7 (17)  Level of education, % high school only 60.7 (17)  Racial/ethnic category   Non-Hispanic White 12 (3)   Non-Hispanic Black 76 (19)   Hispanic Black 12 (3)  Marital status, % married 25 (7)  Parity, % primiparous 28 (7) Abbreviations: CMF, cow's milk formula; pPHF, partial protein hydrolysate formula; SPF, soy-protein formula. Table options Association between maternal distraction and infant intake Eight of the 28 mothers tested (28.6%) were classified as distracted. There was no association between distraction and infant formula/milk consumption (distracted: 133.4 ml ± 18.6 ml vs. not distracted: 111.2 ml ± 11.7 ml, F[1, 25] = 1.01, p = 0.24, η2p = 0.04). Infant age and temperament dimensions were explored as possible moderators of the association between maternal distraction and infant intake. Before inclusion of these variables as possible moderators, the association of each variable with infant intake was assessed. There was no association between formula type and the amount consumed (CMF: 139.1 ± 19.4 ml; pPHF: 113.0 ± 15.4 ml; SPF: 126.8 ± 24.7 ml, F[3, 23] = 1.47, p = 0.25, η2p = 0.16). There was, however, a trend toward infants consuming significantly less when breast-milk was in the bottle compared to formula (breast milk: 67.5 ± 28.9 ml vs. formula: 123.6 ± 10.0 ml; F[1, 25] = 3.37, p = 0.08, η2p = 0.12). In addition, there was a significant association between age and amount consumed in that younger infants (1.6–10.9 weeks of age: 93.9 ± 12.6 ml) consumed significantly less than older infants (11–24 weeks of age: 141.3 ± 12.6 ml; F[1, 25] = 7.01, p = 0.01, η2p = 0.22). There was no association between mothers' perceptions of infants' negative affectivity (F[1, 25] = 0.01, p = 0.93, η2p = 0.00) or orienting/regulation capacity (F[1, 25] = 1.77, p = 0.20, η2p = 0.06) and amount consumed. Conversely, infants classified as high on surgency/extraversion consumed significantly more than infants classified as low on surgency/extraversion (138.8 ± 12.9 ml vs. 96.3 ± 12.9 ml, respectively; F[1, 25] = 5.40, p = 0.03, η2p = 0.18). In tests examining whether any of the above characteristics modified the association between maternal distraction and infant intake, the possible interaction between breast milk vs. formula and distraction could not be tested because none of the mothers feeding breast-from a bottle were classified as distracted. When analyses were limited to mothers who fed their infants formula, there was no interaction between formula type and distraction (F[2, 20] = 0.75, p = 0.49, η2p = 0.07). There was a trend toward an interaction between distraction and infant age (F[1, 23] = 3.93, p = 0.06, η2p = 0.15; Fig. 1). Post-hoc comparisons revealed that when infants were younger (1.6–10.9 weeks of age) there was no association between maternal distraction and infant intake (distracted: 94.5 ± 23.0 ml, not distracted: 95.0 ± 14.5 ml, p = 0.99). In contrast, older infants (11–24 weeks of age) of distracted mothers trended toward consuming more than older infants of mothers who were not distracted (distracted: 174.4 ± 23.0 ml, not distracted: 126.7 ± 14.5 ml, p = 0.09). Infant age trended toward moderating the association between maternal ... Fig. 1. Infant age trended toward moderating the association between maternal distraction and infant intake. When infants were older (11–24 weeks of age), there was a trend toward infants of distracted mothers consuming more than infants whose mothers were not distracted (p = 0.09). Maternal distractedness was not associated with amount consumed for younger infants (1.6–10.9 weeks of age; p = 0.99). Figure options The association between maternal distraction and infant intake was also modified by two dimensions of mothers' perceptions of infant temperament: orienting/regulation capacity (F[1, 23] = 5.53, p = 0.03 for the interaction, η2p = 0.19; Fig. 2) and surgency/extraversion (F[1, 23] = 4.59, p = 0.04 for the interaction, η2p = 0.17; Fig. 3). With respect to orienting/regulation capacity, when infants had low levels of orienting/regulation capacity, those whose mothers were distracted consumed significantly more formula than those whose mothers were not distracted (177.1 ml ± 33.8 ml vs. 92.4 ml ± 13.8 ml, p = 0.03). In contrast, when infants had high levels of orienting/regulation capacity, the association between maternal distraction and infant intake was not significant (p = 0.44). In addition, when mothers were not distracted, infants who were low in orienting/regulation capacity consumed significantly less than infants who were high in orienting/regulation capacity (92.4 ml ± 13.8 ml vs. 139.3 ml ± 16.9 ml, p = 0.04). With respect to surgency/extraversion, for infants with low levels of surgency/extraversion, those whose mothers were distracted consumed significantly more than those whose mothers were not distracted (140.6 ml ± 22.5 ml vs. 78.4 ml ± 14.3 ml p = 0.03, respectively). In addition there was no association between maternal distraction and infant intake when infants had high levels of surgency/extraversion (p = 0.54). Mothers' perception of infants' orienting/regulation capacity moderates the ... Fig. 2. Mothers' perception of infants' orienting/regulation capacity moderates the association between maternal distraction and infant intake. For infants low in orienting/regulation capacity (self-regulation skills), those whose mothers were distracted consumed significantly more formula/milk than infants whose mothers were not distracted (p = 0.03). However, when mothers were not distracted, infants who were low in orienting/regulation capacity consumed significantly less than infants who were high in orienting/regulation capacity (p = 0.04). Different letters between and among groups indicate significant differences in amounts consumed (p < 0.05). Figure options Mothers' perception of infants' surgency/extraversion moderates the association ... Fig. 3. Mothers' perception of infants' surgency/extraversion moderates the association between maternal distraction and infant intake. Among infants low in surgency/extraversion, formula/milk intake was significantly higher when mothers were distracted compared to when mothers were not distracted (p = 0.03). When infants were high in surgency/extraversion, there was no significant difference in formula/milk intake between infants of distracted vs. not-distracted mothers (p = 0.54). Different letters between and among groups indicate significant differences in amounts consumed (p < 0.05). Figure options Association between maternal distraction and maternal sensitivity to infant cues A significantly larger proportion of distracted mothers scored low on the Sensitivity to Cues subscale of NCAFS compared to mothers who were not distracted. Specifically, whereas 75% of distracted mothers scored low on the Sensitivity to Cues subscale, only 30% of mothers who were not distracted scored low on this subscale (p = 0.04, Fisher's Exact Test).