Role of the child and parent

Reports suggest that from an early age children have strong preferences for certain foods and can make their own decisions with respect to the type and PS of food offered for consumption. Results from focus group discussions demonstrate that children between the ages of 6 and 11 years, rely on certain physical cues to decide on an appropriate PS. These include ‘tummy growling’ and ‘your brain telling you’, previous experience with the food(s), as well as PS served by parents and parental guidance^{(Reference Eck, Delaney and Leary29)}. These findings indicate that parental PS decisions may be child-driven and reflect the critical role played by parents in connection with child PS.

Parents report a conscious desire to set an example based on their own food PS decisions, however these are found to be largely based on the amounts they serve themselves^{(Reference Johnson, Hughes and Cui26,Reference Eck, Delaney and Leary29)} . Two experimental studies^{(Reference Johnson, Hughes and Cui26,Reference Reale, Simpson and Marr30)} have demonstrated a positive correlation between parental and child PS when parents serve a meal or a snack in the home environment. Thus, if a parent serves themselves a larger/smaller PS than appropriate, they are likely to do the same for their child. Results from qualitative studies in this area are mixed. For example, in support of the experimental research, parents report that they use their own PS as a guide for determining PS for their child^{(Reference Eck, Delaney and Leary29,Reference Philippe, Issanchou and Roger31,Reference Curtis, Atkins and Brown32)} , while others report using their own intuition, previous experience and knowledge/perception of the child's appetite^{(Reference Eck, Delaney and Leary29,Reference Philippe, Issanchou and Roger31,Reference Croker, Sweetman and Cooke33–Reference Blake, Fisher and Ganter37)} . Furthermore, research using the ‘think aloud’ method, in which parents verbalise their thoughts during food preparation, has indicated that maternal PS decisions can be automatic and influenced by the mother's own hunger and liking of the food product^{(Reference Reale, Marr and Cecil36)}. Fig. 1 gives an overview of the different factors influencing parental PS decisions.

Fig. 1. Factors influencing parental portion size decisions. PS, Portion Size.

Ethnicity and parental childhood mealtime experiences

Differences in parental PS decisions and strategies based on ethnicity have been noted. For example, white parents are more likely to consider PS compared to African American and Hispanic parents^{(Reference Blake, Fisher and Ganter37)}. Similarly, English-speaking mothers in the United States of America (US) reportedly allow their children more autonomy than Spanish-speaking parents with respect to PS decisions^{(Reference Eck, Delaney and Leary29)}. However, Chinese mothers living in the UK are shown to share PS strategies with British mothers^{(Reference Tang, Wang and Croden38)}, suggesting an important role for environment despite ethnicity. There is also evidence that parental PS decisions may be influenced by their own mealtime experiences as children^{(Reference Philippe, Issanchou and Roger31)}. Parents are shown to be motivated by their personal experiences as children, with some expressing a desire to avoid replicating personal negative experiences, such as being told to ‘clean their plates’ to avoid food waste^{(Reference Schuster, Szpak and Klein39,Reference Johnson, Goodell and Williams40)} . Notably, parents have been shown to influence indulgent feeding practices, for example, providing larger PS of treats, in an effort to give themselves and their children more positive mealtime experiences^{(Reference Schuster, Szpak and Klein39,Reference Puhl and Schwartz41)} . Also, PS decisions appear to be passed on from one generation to the next in what has been termed as inter-generational transmission^{(Reference Reale, Simpson and Marr30,Reference Philippe, Issanchou and Roger31)} , defined as ‘the process through which purposively or unintentionally, an earlier generation psychologically influences parenting attitudes and behaviour of the next generation’^{(Reference van Ijzendoorn42)}. This process has been observed in health^{(Reference Ahlburg43)}, stress response^{(Reference Bowers and Yehuda44)} and parenting behaviour^{(Reference Madden, Domoney and Aumayer45)}.

Other family members

Parents with children of varying ages have been shown to acknowledge that each child is different and that PS decisions should differ accordingly^{(Reference Croker, Sweetman and Cooke33)}. However, there is evidence to suggest that PS decisions for younger children in a household are likely to be based on the PS offered to the older children^{(Reference Eck, Delaney and Leary29,Reference Philippe, Issanchou and Roger31,Reference Douglas, Clark and Craig46)} . The role of partners and grandparents in the provision of appropriate child PS has not been widely examined. Partner support has been shown to facilitate healthier food choices in general^{(Reference Peters, Parletta and Lynch47)}, whereas contrastingly, US mothers have indicated that their views on food type and PS differ from those of their partners, reporting that their partners are more likely to purchase larger amounts of food for their child and contribute to the availability of high-energy dense (HED) foods in the home^{(Reference Lora, Cheney and Branscum48)}. Fathers are also reported by mothers to be more likely to engage in an indulgent feeding style, for example, pressurising children to eat, using food to regulate child emotion, using food as a reward and presenting larger food PS^{(Reference Lora, Cheney and Branscum48–Reference Philippe, Chabanet and Issanchou50)}. Grandparents play an integral role in caring for their grandchildren, in particular those of preschool-age^{(Reference Philippe, Chabanet and Issanchou50,Reference Rogers, Bell and Mehta51)} . As such grandparents facilitate the development of their grandchildren's attitudes towards food and subsequent food preferences^{(Reference Curtis, Atkins and Brown32,Reference Rogers, Bell and Mehta51–Reference Faith, Van Horn and Appel53)} . However, grandparents reportedly practice more autonomy promoting behaviour, especially with regards to provision of sweet treats, are shown to use food as a reward, and are also reported to serve large PS of HED foods^{(Reference Curtis, Atkins and Brown32,Reference Schuster, Szpak and Klein39,Reference Douglas, Clark and Craig46,Reference Marr, Reale and Breeze52)} . Notably, mothers report believing that their own parents practiced more restrictive parenting styles as parents than as grandparents^{(Reference Douglas, Clark and Craig46)}.

Child weight status

Parental feeding practices may differ based on child weight status. In a study involving siblings aged between 6 and 12 years, parents were more likely to use restrictive feeding practices with their overweight child than with their healthy weight child^{(Reference Berge, Tate and Trofholz54)}. Parents consider that it is their responsibility to ensure their child is of a healthy weight by providing appropriate foods and managing their food PS^{(Reference Douglas, Clark and Craig46)}. However, they report feeling ill-equipped to discuss child body weight status,^{(Reference Peters, Parletta and Lynch47)} at the risk of inducing anxiety, especially with older children^{(Reference Curtis, Atkins and Brown32)}. Results from quantitative studies suggest that parental decisions on both food type and PS are influenced by child weight status^{(Reference Vanhala, Laitinen and Kaikkonen55–Reference Dickin and Seim57)}. Specifically, mothers of children with obesity showed higher rates of encouragement for a large PS of vegetables than for treat foods. Notably however no differences in PS of fruits, berries and vegetables selected by children based on weight status were observed^{(Reference Vanhala, Laitinen and Kaikkonen55)}. Qualitative evidence indicates that even when parents are not specifically concerned with their child's food PS, they would be worried if their child put on weight, especially if they felt their child showed signs of being unable to control food consumption^{(Reference Eck, Delaney and Leary29,Reference Croker, Sweetman and Cooke33)} . Further qualitative evidence found parents to be concerned about their child being teased as a result of being overweight^{(Reference Curtis, Atkins and Brown32)}, albeit focus group discussions among 34 Scottish mothers indicate a difficulty among mothers in recognising whether or not their child is overweight^{(Reference Douglas, Clark and Craig46)}. Taken together, these findings indicate an overall willingness of parents to manage their child's weight and avoid the development of unhealthy eating patterns. The findings also indicate a lack of guidance for parents on how to deal with weight status issues in their children, albeit it is difficult for parents to recognise when their child is overweight^{(Reference Curtis, Atkins and Brown32,Reference Douglas, Clark and Craig46)} .

Food type and other influencers

Parental perception of the healthfulness of a food product influences PS decisions^{(Reference Blake, Fisher and Ganter37)} with results from qualitative studies indicating that parents are more likely to control the PS offered of HED foods compared to more healthful options^{(Reference Eck, Delaney and Leary29,Reference Reale, Simpson and Marr30,Reference Croker, Sweetman and Cooke33,Reference Dickin and Seim57)} . In a study analysing the portions of low-energy dense (LED) and HED foods offered to children aged 2–4 years, 46 % of parents chose PS of HED snacks that were smaller than the suggested serving size, while 28 % chose PS that were greater^{(Reference Reale, Simpson and Marr30)}. This finding is further supported by the diminutive terms cited by 60 parents in a US study such as, ‘something small’, and ‘a little bit’ when asked to describe age-appropriate portions of snack foods^{(Reference Blake, Fisher and Ganter37)}.

Evidence suggests that parents tend to compare the PS they serve their children with the PS served by other parents in their social circle, particularly where parent peers have children in a similar age group^{(Reference Philippe, Issanchou and Roger31,Reference Martin-Biggers, Spaccarotella and Hongu35,Reference Johnson, Goodell and Williams40)} . In addition, parents consider the influence that a child's peers may have on PS and food intake, with some stating that this is only relevant out of the home^{(Reference Eck, Delaney and Leary29)}, while others believe that peer influence from nurseries and out-of-home experiences ultimately impact child food preferences and intake both in and/or out of the home^{(Reference Tang, Wang and Croden38)}. Indeed, many parents describe controlling PS out-of-home as a challenge, as eating out-of-home is generally considered a treat^{(Reference Blake, Fisher and Ganter37,Reference Tang, Wang and Croden38)} . However, there is also evidence suggesting that parents are more likely to offer pre-packaged crisps and biscuits when out-of-home compared to when at home, in addition to being more relaxed about PS when out-of-home^{(Reference Blake, Fisher and Ganter37)}. Weekend v. weekday intake is also thought to influence parental PS decisions, with significantly larger PS of HED food such as chips, fried foods and sweet snacks/desserts observed among children at weekends compared to weekdays^{(Reference Hoffmann, Marx and Burmeister58)}. This finding is supported by qualitative evidence from France indicating that food habits differ between weekends and weekdays, especially with respect to the type of meal served^{(Reference Philippe, Issanchou and Roger31)}. Other parental considerations include the proximity to the last/next eating occasion and the PS of food previously consumed by the child during the day^{(Reference Croker, Sweetman and Cooke33,Reference Blake, Fisher and Ganter37,Reference Johnson, Goodell and Williams40)} . Parents may also base their PS decisions on level of physical activity undertaken by the child, with larger PS offered when children are considered to be more active^{(Reference Philippe, Issanchou and Roger31,Reference Reale, Marr and Cecil36)} .

Packaging

Qualitative studies from the UK and US^{(Reference Walton, Haycraft and Jewell12,Reference Martin-Biggers, Spaccarotella and Hongu35,Reference Blake, Fisher and Ganter37,Reference Schuster, Szpak and Klein39,Reference Puhl and Schwartz41)} provide evidence that pre-portioned snacks are a common strategy for parents to manage their child's PS. UK mothers of children aged 2–4 years, have reported package size as being useful for determining the amount to offer at any one time^{(Reference Reale, Marr and Cecil36)}. Further research suggests that disposable food and drink packages are commonly reused by parents as a reference to help estimate subsequent PS^{(Reference Tang, Wang and Vazirian59)}. Indeed when parents buy larger packages of food products, they typically repackage the food into individually wrapped units^{(Reference Blake, Fisher and Ganter37,Reference Tang, Wang and Croden38)} . Also, parents report using pre-packaged snacks to prevent negotiation and children asking for more^{(Reference Tang, Wang and Croden38)}. These findings highlight the value of unit-based food packaging in relation to providing child appropriate food PS, offering an opportunity to food manufacturers.

Modelling

Modelling of desired healthful PS behaviours has been shown to have a consistent impact on improving dietary behaviours in children^{(Reference Eck, Delaney and Leary29,Reference Martin-Biggers, Spaccarotella and Hongu35,Reference Lindsay, Sussner and Kim60–Reference Holley, Haycraft and Farrow62)} . Parents report an awareness that their children mimic their food behaviour and are influenced by how much they (the parents) serve themselves^{(Reference Eck, Delaney and Leary29)}. Parents believe that eating with their children provides them with an opportunity to teach children about what to eat, and to encourage appropriate table manners^{(Reference Campbell, Crawford and Hesketh61)}. Interestingly there is some evidence to suggest that children are particularly likely to model healthy eating practices^{(Reference Lora, Cheney and Branscum48)}. Further evidence from Finland in this regard, indicates that parental consumption of fruits and vegetables predicts consumption among 8-year-old children^{(Reference Vanhala, Laitinen and Kaikkonen55)}. Notably, among children aged 2–4 years, a combination of modelling, use of rewards and repeated exposure has been shown to improve liking and consumption of a previously disliked vegetable^{(Reference Holley, Haycraft and Farrow62)}.

Portion size estimation aids

Adults on the island of Ireland reportedly prefer ‘visual’ tools to help estimate appropriate PS^{(Reference Faulkner, Livingstone and Pourshahidi63)}. Likewise, parents have reported using charts, child-sized plates, their own hands, plates with dividers or tablespoons^{(Reference Eck, Delaney and Leary29,Reference Philippe, Issanchou and Roger31,Reference Curtis, Atkins and Brown32,Reference Tang, Wang and Croden38)} to determine appropriate PS for their children. Notably the use of large dishware is thought to challenge this ability^{(Reference Curtis, Atkins and Brown32,Reference Croker, Sweetman and Cooke33)} and some parents report using child-sized utensils as a strategy^{(Reference Philippe, Issanchou and Roger31)}. In observational studies investigating parental v. child estimates of PS, results indicate a large variability between parents and children^{(Reference Collins, Bucher and Taylor64,Reference Potter, Ferriday and Griggs65)} . Specifically, parental PS estimations only aligned with child estimates as child BMI increased^{(Reference Potter, Ferriday and Griggs65)}. Intervention studies examining parental use of PSEA in children are limited. Available studies have largely focused on parental self-efficacy in identifying and/or measuring appropriate child PS^{(Reference Fulkerson, Friend and Horning66,Reference Hughes, Power and Beck67)} . Specifically, parents of children aged 8–12 years, were better able to identify child-appropriate PS following a home-based intervention study targeted at childhood obesity^{(Reference Fulkerson, Friend and Horning66)}. Further evidence among parents of children aged 3–5 years indicates an increase in the use of measured portions following an obesity prevention programme on self-regulation and healthy preferences^{(Reference Hughes, Power and Beck67)}. These findings highlight the use of PSEA as a potentially important strategy in the provision of age-appropriate food PS, and the success of their use in the home environment should be further explored.

Autonomy

Evidence suggests that providing children with a degree of autonomy with respect to PS from an early age has several positive outcomes in relation to PS behaviour^{(Reference Eck, Delaney and Leary29)}. Three main scenarios have been highlighted with respect to autonomy: 1. Guided autonomy, where PS decisions are jointly shared between the parent and the child, with some families negotiating with the child on the food portions served^{(Reference Eck, Delaney and Leary29,Reference Croker, Sweetman and Cooke33,Reference Loth, Nogueira De Brito and Neumark-Sztainer34)} ; 2. Full autonomy, where the child is given total control over their own PS^{(Reference Eck, Delaney and Leary29,Reference Philippe, Issanchou and Roger31,Reference Loth, Nogueira De Brito and Neumark-Sztainer34)} ; 3. No autonomy, where the PS decision is largely taken by the parent^{(Reference Croker, Sweetman and Cooke33,Reference Loth, Nogueira De Brito and Neumark-Sztainer34)} . In cases where no autonomy was given, parents considered safety and utensils not being ‘child-friendly’, as the rationale, as well as a desire to avoid messy situations (especially with younger children)^{(Reference Philippe, Issanchou and Roger31)}. Parents were also of the opinion that the child may be unable to serve themselves the appropriate PS if given full autonomy^{(Reference Philippe, Issanchou and Roger31,Reference Loth, Nogueira De Brito and Neumark-Sztainer34)} . Meal type has been reported to play a role in the level of autonomy given to the child, with more autonomy given for a breakfast meal or a snack, compared to lunch or dinner^{(Reference Philippe, Issanchou and Roger31,Reference Loth, Nogueira De Brito and Neumark-Sztainer34)} . However, for the most part, parents do not allow complete autonomy, preferring guided autonomy while taking the child's preferences into account^{(Reference Loth, Nogueira De Brito and Neumark-Sztainer34)}. Notably, results from an experimental study investigating mealtime structure have demonstrated that children, aged 2–4 years, who are involved in food choice and selection of PS, are less likely to refuse food during the meal^{(Reference Powell, Farrow and Meyer68)}. Further evidence demonstrates that when children are included in food choice and meal preparation, they exhibit less food fussiness and greater food enjoyment^{(Reference Powell, Farrow and Meyer68–Reference Russell, Worsley and Campbell70)}. Allowing some level of autonomy with respect to PS in the home environment may therefore be beneficial to the development of positive PS behaviours in children.

Replacement, reduction and satiety cues

Among preschool children in childcare facilities, serving a variety of vegetables and fruit leads to increased consumption^{(Reference Spill, Birch and Roe24,Reference Roe, Meengs and Birch71)} , suggesting the potential for a similar influence in the home setting. Evidence from the UK investigating replacement of HED snacks with LED options and reduction in PS of HED snacks by 50 %, are shown to be successful strategies for PS control in young children (mean age 36⋅6 ± 9⋅5 months)^{(Reference Reale, Kearney and Hetherington27)}. Further results show that replacement influences children's intake more positively compared to reduction, though both strategies were well received and applied by mothers^{(Reference Reale, Kearney and Hetherington27)}. Indeed, increasing the PS of vegetables served during a meal while decreasing the portions of other components has been reported by a group of US parents as a useful strategy to optimise vegetable intake among their children aged 6–11 years^{(Reference Eck, Delaney and Leary29)}. In relation to reduction, parents have reported both cutting up the food to give children the impression that there was a larger portion than what was available in reality^{(Reference Reale, Marr and Cecil36)}, as well as the sharing of snacks as a portion control strategy^{(Reference Reale, Marr and Cecil36,Reference Tang, Wang and Croden38)} .

It has been reported by parents in qualitative studies that offering a small portion of food first, then offering more in response to the child's cues is a portion control strategy^{(Reference Philippe, Issanchou and Roger31,Reference Croker, Sweetman and Cooke33,Reference Loth, Nogueira De Brito and Neumark-Sztainer34)} . Parents report relying on feedback from the child with respect to satiation, as well as having an implicit agreement with the child that they could ask for second helpings, but only if they finished their first helping of the meal^{(Reference Loth, Nogueira De Brito and Neumark-Sztainer34,Reference Reale, Marr and Cecil36)} . In qualitative research conducted among children aged 6–11 years, mixed opinions in relation to how much food to eat were evidenced, with some children stating a reliance on parents, e.g. ‘My dad, if he thinks we're eating a lot, will tell us to wait and see if we feel full and if we're still hungry later’ ^{(Reference Eck, Delaney and Leary29)}, while others reported relying on their intuition, e.g. ‘my tummy tells me to stop eating’ and ‘eating less than their parents portions’ ^{(Reference Eck, Delaney and Leary29)}.