Ch.8- The Development of Eating Behaviors

• Effects on Prenatal Development

  • Famine during gestation is associated with later health problems in life (diabetes, hypertension)
• Taste and the Human Newborn

  • Taste cells appear at 14 weeks of gestation
  • Fetus starts episodic swallowing at 12 weeks
  • Fetus exposed in utero to glucose, salts, etc
  • Preterm infant shows sweet preference
• Salt Preference in Infants

  • Infants preference for salt begins at four months
  • Experience doesn't play a role; maturation of the central taste system underlies effects
  • Early life depletion of salt increases salt preference in childhood
  • Causes an organizational effect in nervous system
• Do odors play a role prenatally (exp)

  • Amniotic fluid samples from 10 women
  • 5 consumed garlic, 5 consumed placebo capsule
  • smell judge panel given pairs
  • 4/5 pairs likely identified
  • conclusion: fetus likely exposed to odors
• Mother's Milk and Odor Learning (exp)

  • Hypothesis: Newborns can recognize their mom's milk and underarm odor when compared to other mothers
  • food odor transmitted in breast milk (each mom given either garlic or placebo capsule)
  • Mothers either given alcohol or nonalcohol (OJ or beer) before breastfeeding infant
  • Infants consumed less on alcohol day compared to nonalcohol
• References in Novel Food

  • Birch (1994) studied infants first acceptance of novel food (4-6 months)
  • infants were fed new food by their mom on ten occasions
  • The overexposure period led to an increase in intake(mere exposure effect)
  • Greater increase in breastfed infants compared to formula-fed infants
  • Proving the idea that breastfed infants are exposed to a variety of flavors in mom's milk, which enhances their acceptance of new foods
• Breastfeeding on demand allows infants to control meal size and intermeal interval

  • Bottle-fed infants are not fed on demand, and correlations are not found
• Clara Davis research:

  • Infants starting novel foods (presented tray with 10-12 items and were allowed to pick whatever they wanted)
  • Children were able to regulate food intake despite "food jags"
  • Evidence for "innate self-selection mechanism"
• • Infants consume more of a dilute vs. dense formula
• Birch: kids consumed fewer snacks after being exposed to energy-dense drinks (higher calories)

  • Proves that learning/experience is important.
• Birch: kids selected a balanced diet over a six-day period

  • Proving that overweight children regulate less well + choose fattier foods
• Birch (1994): study 3-5 yr olds

  • kids ate a single meal using preload (eating before) + 2nd course method
  • two conditions: low and high-calorie preload w/ same 2nd course
• What research questions did Birch (1994) examine in their study?

  • Does parenting style impact caloric regulation
  • Does BMI impact regulation
  • Is there a gender difference
• Results of Birch (1994) study:

  1. Regulation of intake was negatively correlated with authoritarian parental controls of overeating
  2. Caloric regulation was negatively correlated with the child's BMI (ex: high BMI -> poor regulation)
  3. Gender difference: obese girls showed less calorie regulation than thin girls; boys showed no difference
  4. Children of parents who had difficulty controlling their own eating also did not regulate calories well
• Internal & External Controls

  • Same exp. design
  • 1st condition: adults (not parents) told children to focus on their internal cues of hunger + satiety
  • 2nd condition: focuses on external cues (ex: how much left on plate, rewards for finishing)
  • Results: Only children in the 1st condition altered intake as function of calories in preload
• Early independent feeding (exp)

  • kids had 2 scheduled meals and also had access to whatever snacks they wanted
  • Results: The kids ate a mean of 13.5 snacks. -Children who ate more snacks consumed more calories (no caloric homeostasis)
• External Influences on Eating

  • Parenting style
  • Demands
  • Focus on external cues
  • Modeling
  • Social influences
  • Food availability + portion sizes
  • Media - McDonald's carrots were preferred - Kids eat more after food commercials
• Conclusions about self-regulation

  • Self-regulation is:
  • Imperfect
  • Shaped by learning
  • Becomes blunted with age
  • Less likely when food is appealing (ex: sweet or salty tastes)
  • External cues become more important with age and experience with food