L6: dietry learning and the development of eating behaviours

What are the key developmental stages through which children acquire food preferences?

• Prenatal: Maternal dietary flavours enter amniotic fluid, enabling fetal chemosensory learning.

• Milk feeding: Breast milk transmits maternal dietary flavours, extending familiarisation.

• Weaning: Repeated tasting and texture exposure shape acceptance.

• Toddlerhood: Neophobia, social learning and parental feeding increasingly influence preferences.

According to Schaal et al. (2000), how does prenatal flavour learning occur?

• Volatile compounds from maternal foods cross into amniotic fluid.

• Fetal swallowing and breathing-like movements expose oral and nasal receptors to these compounds.

• Repeated exposure establishes familiarity and potentially positive hedonic associations before birth.

• Maternal nutrient-related reinforcement is proposed but was not directly demonstrated.

What did Mennella et al. (1995) demonstrate about prenatal flavour exposure?

• Pregnant women consumed garlic capsules or placebo before amniocentesis.

• Amniotic fluid from 4 of 5 garlic-exposed women was judged more garlic-like than paired controls.

• Demonstrates maternal dietary compounds can alter the fetal chemosensory environment, but not that infants subsequently prefer garlic.

What are the strengths and limitations of Mennella et al. (1995)?

• Strength: Direct examination of amniotic fluid provides biological evidence for prenatal flavour transmission.

• Weakness: Only 10 pregnant women limits precision and generalisability.

• Weakness: Odour differences do not establish fetal learning or later food preference.

• Implication: Provides mechanistic groundwork rather than direct behavioural evidence.

How did Schaal et al. (2000) investigate prenatal olfactory learning?

• Compared 24 mother–infant pairs, with 12 mothers consuming anise during late pregnancy and 12 not consuming it.

• Newborns encountered anise and control odours within hours of birth, before their first feed, and again on day 4.

• Blinded coders assessed negative facial expressions, mouthing and head orientation.

What were the key findings of Schaal et al. (2000) concerning newborn responses to anise?

• Prenatally exposed infants showed more appetitive mouthing, with 10/11 responding versus 4/12 unexposed infants.

• Negative facial responses occurred in 2/11 exposed versus 10/12 unexposed infants.

• Exposed infants oriented longer toward anise.

• Supports prenatal learning of maternal dietary odours before postnatal feeding.

What did Schaal et al. (2000) find at the four-day follow-up, and why is this important?

• Exposed infants retained greater head-orientation preference for anise.

• Initial group differences in facial aversion and mouthing had diminished.

• Suggests recognition or approach responses can persist while immediate hedonic expressions change rapidly.

• Does not establish long-term dietary preference.

What are the methodological strengths and weaknesses of Schaal et al. (2000)?

• Strength: Testing before first feeding reduces postnatal flavour exposure as an alternative explanation.

• Strength: Blinded, systematic behavioural coding reduces observer bias.

• Weakness: Small sample and follow-up attrition limit reliability and generalisability.

• Weakness: Non-random maternal dietary groups allow confounding.

• Weakness: Four-day follow-up cannot demonstrate lasting dietary effects.

What did Mennella et al. (2001) find about prenatal and breastfeeding exposure to carrot flavour?

• Mothers consumed carrot juice during late pregnancy, breastfeeding or neither period.

• At weaning, infants exposed during pregnancy or breastfeeding showed fewer negative facial expressions to carrot-flavoured cereal than controls.

• Demonstrates that both prenatal and early postnatal flavour experiences can influence later acceptance.

How do Schaal et al. (2000) and Mennella et al. (2001) complement one another?

• Schaal et al.: Evidence of prenatal odour learning within hours of birth, before feeding.

• Mennella et al.: Evidence that prenatal or lactational flavour exposure can influence responses months later at weaning.

• Together: Support continuity between early chemosensory experience and later food acceptance.

• Qualification: Neither establishes lifelong dietary change.

According to Cooke and Fildes (2011), how does breastfeeding influence later food preferences?

• Maternal dietary compounds transmitted through breast milk expose infants to varied flavours.

• Repeated variation may increase familiarity and prepare infants for complementary foods.

• Breastfeeding associations with healthier diets may depend on maternal food consumption.

• Observational evidence remains vulnerable to socioeconomic and parental dietary confounding.

What did Forestell and Mennella (2007) find about breastfeeding and acceptance of complementary foods?

• Breastfed infants aged approximately 5–6 months consumed peaches more readily and showed fewer negative facial expressions than formula-fed infants.

• No corresponding breastfeeding advantage emerged for green beans.

• Suggests flavour-specific maternal dietary exposure rather than a universal breastfeeding benefit.

What are the limitations of attributing healthier childhood diets directly to breastfeeding, according to Cooke and Fildes (2011)?

• Weakness: Breastfeeding is associated with maternal education, diet and socioeconomic circumstances, creating confounding.

• Weakness: Maternal flavour transfer varies between foods and individuals.

• Weakness: Associations with later dietary variety do not establish causality.

• Implication: Maternal diet and feeding context may be as important as feeding mode.

According to Schwartz et al. (2011), what are the WHEN, WHAT and HOW dimensions of complementary feeding?

• WHEN: Timing of weaning and developmental readiness.

• WHAT: Nutritional content, flavours and textures offered.

• HOW: Repeated exposure, variety, self-regulation, autonomy and parental feeding practices.

• Integrates biological maturation with psychological learning and environmental influences.

According to Schwartz et al. (2011), why is the timing of weaning developmentally important?

• Milk eventually becomes insufficient for nutritional requirements, including iron.

• Infants need sufficient digestive and oral-motor maturity to handle complementary foods.

• WHO guidance recommends complementary feeding around six months.

• Timing must balance nutritional needs, developmental readiness and infection risks.

What did Northstone et al. (2001) and Coulthard et al. (2009) find about introducing lumpy foods?

• Introduction of lumpy textures after 10 months was associated with greater feeding difficulties and food selectivity.

• Difficulties were observed at 15 months and persisted into childhood in follow-up evidence.

• Suggests timely texture experience supports oral-motor development and acceptance.

• Associations do not establish that delayed introduction alone causes later problems.

How does texture exposure influence oral-motor development, according to Schwartz et al. (2011)?

• Chewing and lateral tongue movements develop substantially around 6–10 months.

• Experience with developmentally appropriate textures provides opportunities to practise these skills.

• Prolonged reliance on smooth foods may delay adaptation to complex textures.

• Texture acceptance therefore reflects interaction between maturation and experience.

According to Vereijken et al. (2011), what characterises the transition from milk to meals?

• Children move from a restricted, caregiver-controlled milk environment to a varied food environment.

• Development depends on WHEN physical and cognitive readiness occurs, WHAT sensory experiences are provided and HOW learning takes place.

• Healthy food preferences and cognitive schemas develop through repeated experiences and social interactions.

According to Vereijken et al. (2011), how do food schemas and scripts influence eating behaviour?

• Schemas organise knowledge and expectations about foods, including sensory properties and acceptability.

• Scripts represent familiar sequences of eating events and mealtime routines.

• Positive experiences build expectations of safety and enjoyment. • Established negative expectations may require repeated contradictory experiences to change.

What is food neophobia, and how does Rozin's (1976) omnivore's dilemma explain it?

• Neophobia is reluctance to taste unfamiliar foods.

• The omnivore's dilemma describes the conflict between exploring new food sources and avoiding potentially harmful substances.

• Neophobia may have evolved as protection against poisoning.

• In modern food environments, it can restrict dietary variety and vegetable acceptance.

According to Cooke (2007), how does food neophobia change across childhood?

• Infancy: Relatively low neophobia while caregivers control food provision.

• Toddlerhood: Increases around 12–24 months as mobility and independence develop.

• Preschool years: Often remains prominent.

• Later childhood: Generally declines with accumulated food experience.

• Early introduction may therefore be easier before pronounced neophobia develops.

According to Cooke (2007), what are the major psychological determinants of children's food preferences?

• Innate taste predispositions favour sweetness and discourage bitterness.

• Familiarity develops through repeated experience.

• Sweetness and familiarity together account for approximately 50–60% of variation in young children's food preferences in the evidence reviewed.

• Learning can modify initial predispositions.

What is mere exposure, and how does it promote food acceptance according to Cooke (2007)?

• Repeated encounters increase familiarity with a food's sensory properties.

• Familiarity reduces uncertainty and neophobic responses.

• Repeated tasting can gradually increase liking without requiring explicit rewards.

• The mechanism is especially relevant to initially disliked vegetables.

How does learned safety differ from mere exposure and flavour–consequence learning?

• Mere exposure: Familiarity itself increases acceptance.

• Learned safety: Repeated consumption without adverse consequences reduces perceived risk.

• Flavour–consequence learning: A flavour becomes associated with positive post-ingestive nutritional or energy effects.

• These mechanisms may operate together but are theoretically distinct.

According to Vereijken et al. (2011), what is the difference between flavour–flavour learning and flavour–consequence learning?

• Flavour–flavour learning: Pairing a novel or disliked flavour with a familiar, liked flavour increases its acceptability.

• Flavour–consequence learning: A flavour acquires positive value through association with beneficial post-ingestive effects.

• Both involve associative learning, but the source of reinforcement differs.

According to Maier et al. (2007), how many exposures may be needed to increase acceptance of a disliked vegetable?

• At least eight repeated tasting opportunities were needed for an initially rejected vegetable to reach consumption comparable with an initially accepted vegetable.

• Benefits persisted for many children at nine-month follow-up.

• Parents often stop after only 1–5 attempts, potentially abandoning effective exposure prematurely.

What are the key limitations of repeated exposure as a strategy for increasing vegetable acceptance?

• Weakness: It requires children to taste the food, which is difficult when neophobia produces complete refusal.

• Weakness: Benefits may be specific to particular flavours, textures or food categories.

• Weakness: Repeated provision without actual tasting may have limited effects.

• Implication: Modelling or incentives may be needed to initiate exposure.

According to Schwartz et al. (2011), how does dietary variety influence acceptance of new foods?

• Exposure to multiple vegetables can promote acceptance of subsequently unfamiliar vegetables.

• Changing foods between meals may be particularly effective.

• Variety broadens sensory experience and reduces reliance on a narrow range of familiar flavours.

• Generalisation is not necessarily equivalent across different food categories or textures.

What is the distinction between visual exposure and taste exposure in food preference learning?

• Visual exposure familiarises children with a food's appearance and may increase willingness to try it.

• Taste exposure provides direct sensory and post-ingestive experience needed to establish hedonic liking.

• Visual familiarity may therefore facilitate initial tasting without necessarily producing lasting taste preference by itself.

According to Anzman-Frasca et al. (2018), what principles support healthy food preference development?

• Begin exposure early, before neophobia becomes pronounced.

• Offer repeated opportunities to taste healthy foods without coercion.

• Provide variety across flavours and textures. • Use supportive social modelling and responsive feeding.

• Recognise individual differences in temperament, neophobia and reward responsiveness.

What are the strengths and limitations of Cooke (2007) and Anzman-Frasca et al. (2018) as evidence sources?

• Strength: Reviews integrate findings across developmental stages and learning mechanisms.

• Strength: Identify converging principles for practical interventions.

• Weakness: Narrative synthesis is vulnerable to selective emphasis and heterogeneous study quality.

• Weakness: Short-term acceptance is often treated as a proxy for enduring dietary change.

• Implication: Strong theoretical integration does not replace long-term causal evidence.

According to Schwartz et al. (2011), how does children's appetite self-regulation develop?

• Infants show an ability to adjust intake in response to energy density and internal hunger–satiety cues.

• Increasing age and environmental exposure can make eating more responsive to portion sizes and external prompts.

• Controlling feeding may further undermine attention to internal cues.

• Self-regulation is influenced by both biological and social factors.

According to Schwartz et al. (2011), what distinguishes authoritative feeding from coercive feeding?

• Authoritative feeding combines warmth, responsiveness and appropriate structure.

• Coercive feeding relies on pressure, restriction or disregard for hunger and fullness cues.

• Responsive approaches support autonomy and internal regulation.

• Associations between parenting style and dietary outcomes do not automatically demonstrate causality.

According to Wardle and Carnell (2007), what are four important parental feeding practices?

• Restriction: Limiting access to particular foods.

• Pressure: Encouraging or forcing children to eat more.

• Instrumental feeding: Using food as a reward for behaviour.
• Emotional feeding: Offering food to manage distress.

• Each can influence how children interpret hunger, food value and eating cues.

How can restrictive parental feeding influence children's eating behaviour?

• Restriction can increase the salience and desirability of prohibited foods.

• Children may consume restricted foods when available, including without hunger.

• Explicit restriction can encourage eating in response to external rules rather than internal satiety.

• However, parental restriction may also be a response to existing child weight or appetite.

How can parental pressure to eat undermine healthy food acceptance?

• Pressuring children to finish food may override satiety cues.

• Coercive mealtimes can create negative associations with target foods.

• Pressure may increase resistance and picky eating rather than improve acceptance.

• Parents may pressure children who already eat little, complicating causal interpretation.

What did Wardle and Carnell (2007) conclude about causality between parental control and child weight?

• Parents often restrict heavier children and pressure leaner or low-intake children.

• Feeding practices may therefore respond to child characteristics rather than independently cause weight differences.

• Cross-sectional associations cannot establish direction of causality.

• Bidirectional parent–child influences should be considered.

What are the strengths and limitations of Wardle and Carnell (2007)?

• Strength: Challenges simplistic assumptions that parental control necessarily causes childhood obesity.

• Strength: Considers child-driven and bidirectional explanations.

• Weakness: Much of the reviewed evidence is observational, limiting causal inference.

• Weakness: Parent-reported feeding practices may be biased.

• Implication: Longitudinal and experimental evidence is needed to establish directionality.

What is the difference between overt and covert parental control over food?

• Overt control involves explicit restrictions, commands or pressure directed at the child.

• Covert control structures the food environment without drawing attention to restriction, such as limiting unhealthy snacks purchased.

• Covert approaches may improve food availability while avoiding conflict and heightened interest in forbidden foods.

What is the division of responsibility in responsive feeding, as discussed by Schwartz et al. (2011)?

• Parents determine what foods are offered, when and where eating occurs.

• Children retain responsibility for whether and how much they eat.

• The approach combines structured food provision with respect for hunger and fullness.

• It aims to support autonomy without abandoning nutritional guidance.

According to Stone et al. (2023), why is emotional feeding relevant to the development of eating behaviour?

• Using food to soothe distress can associate eating with emotional regulation rather than physiological hunger.

• Repeated pairings may encourage eating in response to negative affect.

• Parent and child emotional characteristics can influence feeding interactions.

• Observed associations require caution because child distress may itself elicit emotional feeding.

What methodological challenges arise when investigating emotional feeding and later eating problems?

• Weakness: Parent-report measures can introduce recall and social desirability bias.

• Weakness: Child temperament and emotional reactivity may confound associations.

• Weakness: Cross-sectional evidence cannot distinguish parental influence from child-elicited feeding.

• Implication: Longitudinal and experimental designs are needed to test developmental pathways.

According to Rasmussen et al. (2006), what environmental influences shape children's fruit and vegetable intake?

• Availability and accessibility of fruit and vegetables influence opportunities for consumption.

• Parental intake, modelling and family practices shape dietary norms.

• Peer and school environments can also influence choices.

• Individual preferences interact with broader social and physical environments, suggesting multilevel intervention is needed.

According to Gibson et al. (2012), why should interventions consider multiple influences on children's eating?

• Eating behaviour reflects interactions between individual preferences, family practices, social environments and food availability.

• Knowledge or exposure alone may not overcome environmental barriers.

• Effective approaches should support repeated opportunities, positive modelling and accessible healthy choices.

• Intervention feasibility and sustainability are important alongside efficacy.

What psychological mechanisms explain how parental and peer modelling can influence children's food choices?

• Observational learning allows children to acquire food-related expectations from others' behaviour.

• Positive models demonstrate that unfamiliar foods are acceptable and rewarding.

• Peer norms can increase willingness to taste foods.

• Actual tasting may then support familiarity and learned liking.

According to Greenhalgh et al. (2009), why is the context of repeated food exposure important?

• Exposure must provide meaningful opportunities to engage with and consume the target food.

• Social and motivational context can influence whether children initially taste unfamiliar foods.

• Food availability alone does not guarantee acceptance.

• Intervention outcomes should distinguish increased tasting, increased liking and sustained consumption.

What is the rationale behind combining repeated exposure with rewards in childhood feeding interventions?

• Rewards can motivate children to overcome initial reluctance to taste unfamiliar vegetables.

• Repeated tasting then increases familiarity and potentially intrinsic liking.

• Non-food rewards avoid making unhealthy foods the incentive.

• The aim is to establish acceptance that persists after incentives are withdrawn.

According to Holley et al. (2017), what does the evidence suggest about non-food rewards for vegetable acceptance?

• The systematic review found support for tangible non-food rewards, particularly alongside repeated tasting.

• Rewards can increase intake and liking of initially disliked vegetables.

• Some benefits persist after reward withdrawal.

• This challenges the assumption that all external rewards necessarily undermine food preference.

How do food rewards differ psychologically from non-food rewards, according to Holley et al. (2017)?

• Food rewards such as dessert for eating vegetables may increase the reward food's desirability while devaluing the vegetable.

• Non-food rewards such as stickers encourage tasting without positioning another food as more desirable. • Reward type, contingency and context matter.

• Evidence supporting non-food incentives should not be generalised to coercive food rewards.

What is the overjustification hypothesis, and how does Holley et al. (2017) challenge its application to vegetable interventions?

• Overjustification predicts external rewards may undermine intrinsic motivation once withdrawn.

• This concern is less straightforward when children initially dislike the target food and have little intrinsic motivation.

• Reward-induced tasting may allow familiarity and liking to develop.

• Sustained consumption after reward withdrawal challenges a universal overjustification prediction.

What did Holley et al. (2014) find about combining modelling, repeated exposure and rewards?

• Compared repeated exposure alone with approaches incorporating parental modelling and/or rewards.

• Reward-containing conditions produced particularly strong improvements in vegetable intake and liking.

• Suggests incentives and modelling can help children overcome initial refusal.

• The contribution of each component must be evaluated rather than assuming every component is essential.

How do individual differences affect the effectiveness of food rewards, according to Holley et al. (2017) and Anez et al. (2013)?

• Children with high reward sensitivity may respond more readily to tangible incentives.

• Prior experience of instrumental feeding can shape expectations about receiving rewards.

• Children less accustomed to rewards may benefit from repeated exposure alone.

• Supports tailoring interventions rather than universally rewarding every child.

What are the methodological strengths and limitations of reward-based feeding intervention research reviewed by Holley et al. (2017)?

• Strength: Controlled comparisons help identify whether incentives improve acceptance beyond exposure alone.

• Strength: Follow-up assessments test whether gains survive reward removal.

• Weakness: Small samples and differing protocols complicate generalisation.

• Weakness: Short follow-ups cannot establish lifelong dietary change.

• Weakness: Reward-induced intake may not generalise to other foods or contexts.

What were the core components of the Food Dudes intervention evaluated by Horne et al. (2004)?

• Peer-modelling videos depicted admired children eating fruit and vegetables.

• Tangible non-food rewards reinforced consumption.

• Teacher encouragement and programme materials supported participation.

• The intervention combined social learning, contingent reinforcement and repeated tasting to increase fruit and vegetable intake.

What was the design of Horne et al. (2004), and what did the intervention find?

• Studied 749 children aged 5–11 across two matched London primary schools, one intervention and one control.

• Intervention-school lunchtime fruit consumption rose from 20% at baseline to 69% during intervention and remained 56% at four months.

• Control-school intake remained approximately 11% initially and 9% at follow-up.

• Demonstrates substantial maintained improvements.

According to Horne et al. (2004), which children benefited most from Food Dudes?

• Children with the lowest initial fruit and vegetable intake showed particularly large improvements.

• Among very low fruit consumers, intake rose from approximately 4% at baseline to 68% during intervention and remained 48% at follow-up.

• Suggests combined modelling and reinforcement can engage children who are least responsive to ordinary provision.

What are the strengths and methodological limitations of Horne et al. (2004)?

• Strength: Large school-based sample supports ecological relevance.

• Strength: Control-school comparison and follow-up strengthen evidence of intervention effectiveness.

• Weakness: Only two schools, without individual randomisation, leave school-level confounding.

• Weakness: Multiple intervention components prevent isolation of the active mechanism.

• Weakness: Four-month maintenance does not establish lifelong change.

How did Morrill et al. (2016) extend the Food Dudes intervention research?

• Conducted a cluster-randomised trial involving 2,292 children across six US elementary schools.

• Compared Food Dudes with tangible prizes, Food Dudes with teacher praise and a no-treatment control.

• Examined whether cheaper social reinforcement could substitute for tangible rewards while maintaining consumption gains.

What were the main short-term findings of Morrill et al. (2016)?

• Tangible-prize intervention increased fruit and vegetable intake by approximately 92% relative to control during the initial intervention.

• Teacher praise increased intake by approximately 50% relative to control.

• Both reinforcement strategies produced short-term improvements, but tangible prizes produced the larger effect.

What did Morrill et al. (2016) find about longer-term maintenance of Food Dudes effects?

• At six-month follow-up, the tangible-prize group maintained approximately 43% higher fruit and vegetable intake than control.

• The teacher-praise group no longer differed significantly from control.

• Suggests tangible rewards were more effective than praise for maintaining behaviour change in this implementation.

What are the strengths and limitations of Morrill et al. (2016)?

• Strength: Cluster randomisation across six schools improves causal evidence compared with non-random school comparisons.

• Strength: Large sample and objective photographic plate-waste assessment strengthen measurement.

• Strength: Six-month follow-up evaluates maintenance.

• Weakness: Self-reported intake during maintenance may be biased.

• Weakness: No home-intake or BMI assessment limits conclusions about broader health outcomes.

How do Horne et al. (2004) and Morrill et al. (2016) collectively inform Food Dudes interventions?

• Both support combined peer modelling, reinforcement and repeated tasting to increase fruit and vegetable intake.

• Horne et al. demonstrated large gains in a naturalistic school setting.

• Morrill et al. provided stronger comparative evidence that tangible rewards outperform praise for longer-term maintenance.

• Neither fully isolates modelling from exposure and reinforcement effects.

What are the major limitations of translating successful dietary learning interventions into obesity prevention?

• Increased liking or consumption of vegetables does not necessarily reduce total energy intake.

• Children may compensate by changing consumption of other foods.

• Short-term dietary improvements may not persist across developmental stages.

• Many studies do not measure adiposity or long-term health.

• Therefore, improved food acceptance is a plausible pathway rather than proof of obesity prevention.

According to Schwartz et al. (2011) and Vereijken et al. (2011), what is the main research-to-practice gap in early feeding guidance?

• Research supports repeated tasting, dietary variety, appropriate texture progression and responsive feeding.

• Guidance often lacks specific, practical advice for managing rejection or implementing these strategies.

• Parents may abandon vegetables after only a few refusals.

• Translating evidence into accessible, feasible parental strategies is essential.

How can the evidence from Schaal et al. (2000), Cooke (2007), Wardle and Carnell (2007), and Horne et al. (2004) be synthesised into an account of healthy eating development?

• Early chemosensory exposure establishes familiarity before independent eating.

• Repeated tasting modifies preferences and reduces neophobia.

• Responsive parental practices support autonomy and avoid coercive associations.

• Modelling and rewards can overcome barriers to tasting.

• Overall, eating behaviour develops through interacting biological, learning and environmental processes.

What is the strongest critical conclusion about dietary learning and childhood eating interventions across this lecture?

• Strength: Converging experimental, developmental and intervention evidence demonstrates that food preferences are modifiable.

• Limitation: Mechanisms are often inferred from multi-component interventions rather than directly isolated.

• Limitation: Samples, feeding environments and cultural contexts restrict generalisability.

• Limitation: Long-term obesity outcomes are rarely established.

• Conclusion: Early learning interventions are promising, but durable population-level effects require stronger longitudinal and implementation evidence.