Obesity Runs in Families. University of Tennessee, Knoxville; Promoting Healthy Weight Colloquium (Early Childhood) March 25, 2011

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1 Family Influences on the Development of Child Eating Behaviors Tanja V.E. Kral, Ph.D. Assistant Professor of Nutrition University of Pennsylvania U.S. Childhood Obesity Trends By school entry, more than 20% of 2- to 5- year-old children are considered overweight or obese (Ogden et al., 2010). Pediatric Obesity: Body Mass Index (BMI)- for-age 95 th percentile Source: National Center for Health Statistics, part of the Centers for Disease Control and Prevention Obesity Runs in Families Parental obesity more than doubles the risk of adult obesity in the offspring (Whitaker et al., 1997). Children whose mothers were obese showed more than a 3-fold increased risk of childhood obesity (Strauss & Knight, 1999). 1

2 Genetic Influences on Child Weight and Eating Body weight and body composition (e.g., Maes et al., 1997) Appetitive traits (e.g., satiety responsiveness) (e.g., Wardle & Carnell, 2009) Food preferences (e.g., Breen et al., 2006) Eating behaviors (energy compensation ability, eating in the absence of hunger) (e.g., Fisher et al., 2007; Cecil et al., 2007) Microstructure of eating (e.g., eating rate) (e.g., Llewellyn et al., 2008) (Home) Environmental Influences on Child Weight and Eating Parents own eating behaviors (e.g., modeling) (e.g., Cutting et al., 1999) Child feeding practices (e.g., Anzman & Birch, 2009) Availability and accessibility of (un)healthy foods (e.g., Cullen et al., 2003) Portions of foods served to children (Fisher & Kral, 2008) Repeated exposure to novel foods (e.g., flavor learning) (e.g., Sullivan & Birch, 1994). Gene-Environment Interactions Nature Nurture Individual Susceptibility Regulation of Hunger / Fullness Responsiveness to Food Cues Food Preferences Physical Activity Preferences Energy Balance Weight Status / Adiposity Environment Access to Healthy & Unhealthy Foods Food Portion Size Built Environment Adapted from Carnell & Wardle, Proc Nutr Soc; 67: ,

3 Early-Life Regulation of Energy Intake Infant Eating Patterns In 1928 Clara Davis studied eating patterns of infants in a pediatric ward. 1 While self-selecting their diets for several months, infants grew normally and were healthy. Such successful [ ] balancing of the more than thirty nutritional essentials [ ] suggests at once the existence of some innate, automatic mechanism for its accomplishment, of which appetite is a part. 2 However, Davis also observed that infants [ ] tastes changed unpredictably [ ] and would have been a dietician s nightmare [ ] and that infants showed an erratic behavior of appetite. 2 1 Davis, Am J Dis Child, 36, , 1928; 2 Davis, Can Med Assoc J, 41, , 1939 Infants Ability to Regulate Energy Intake Figure constructed from data presented in Fomon et al., J Nutr, 98, ,

4 Meal-to-Meal Variability in Energy Intake For each child, energy intake at a given meal or snack was highly variable (mean CV = 34%). In contrast, the variability of daily energy intake was low (mean CV = 10%). Evidence for considerable individual differences in patterns of intake. Copyright 1991 Massachusetts Medical Society Birch et al., N Engl J Med, 324, 232-5, 1991 Rapid Eating Rate: A Risk Factor for Overeating & Excessive Weight Gain? Some evidence suggesting that overweight children show greater eating rate and slower deceleration of eating over course of a meal (Waxman & Stunkard, 1980; Barkeling et al., 1992). Eating rate shown to be heritable (h 2 = 0.62) (Llewellyn et al., 2008). Longitudinal studies needed to examine causal relationships between child adiposity and eating rate. High-Risk Design of Obesity Longitudinal study of growth and development in children born with different familial predispositions to obesity. Children s obesity risk status based on maternal pre-pregnancy BMI (normal-weight: low-risk (LR); overweight / obese: high-risk (HR)). Adapted from Berkowitz et al., Am J Clin Nutr, 81: 140-6,

5 Risk-Group Differences in Infant Sucking Behavior Sucking Characteristic Low-risk (n = 38) High-risk (n = 40) Total number of sucks 620 ± ± 89* Sucking rate (sucks/s) 0.59 ± ± 0.01* Amount consumed (g) 123 ± ± 9* Stunkard et al., Am J Clin Nutr, 69: , 1999 Assessment of Eating Rate at Age 4 in the Laboratory Subset of cohort (29 LR and 32 HR children) consumed test meal in the presence of a parent. Test meal consisted of a variety of foods (e.g., macaroni and cheese, French fries, vegetables, applesauce) and beverages (e.g., milk, apple juice, fruit punch). Meal consumption was videotaped and coded. Eating rate was computed as calories/min and mouthfuls/min. Associations Between Eating Rate and Energy Intake and Weight Status Trend for greater mouthfuls/min (2.6 vs. 2.2, P = 0.10) by HR than LR children. Energy intake/min was correlated with meal energy intake and daily energy intake (r > 0.40, P < 0.005). Mouthfuls/min and kcal/min at age 4 was associated with increased probability of child overweight at age 6 (P < 0.04). Copyright 2009 Nature Publishing Group Berkowitz et al., Obesity, 18: ,

6 Modifications in Eating Rate: A Strategy to Moderate Energy Intake? Rapid eating rate may be a risk factor for overeating and excessive child weight gain. Interventions designed to slow eating rate in obesityprone children may be a promising strategy to moderate children s energy intake (Epstein et al., 1976). More studies are needed which systematically vary children s eating rate across different types of foods. Familial Influences on Healthy and Less Healthy Eating in Children Familiarity and Neophobia Food Preferences Family Influences Sensory and Food Properties Eating Behavior (Home) Food Environment Reward Value of Foods Social Factors 6

7 Copyright 1928, The New Yorker Maternal Influences on Child Eating Behavior Early home food environment (accessibility / availability of (un)healthy foods) influences child eating and formation of food preferences. Mothers influence their children s eating in multiple ways: Exposure to food flavors and different types of foods (e.g., Forestell & Mennella, 2007) Important role models (e.g., Fisher et al., 2002) Use of child feeding practices (e.g., Fisher et al., 2002) Pre- and Postnatal Flavor Learning The extent to which flavors are liked or disliked is determined by inborn and environmental (learning) factors and their interactions (Beauchamp & Mennella, 2009). Prenatal sensory experiences (flavors transmitted from mother s diet to amniotic fluid) can affect newborn s acceptance and intake of foods. Copyright 2001 American Academy of Pediatrics Mennella et al., Pediatrics, 107, e88,

8 Intake of Fruits and Vegetables: Mother Child Associations Evaluate associations between children s and their mothers fruit and vegetable (F&V) intake (servings/d) and children s F&V intake and their weight status. 39 mothers completed a subsection of the Diet History Questionnaire assessing their habitual intake of fruits (13 questions) and vegetables (21 questions) over the previous 12 months. Mothers also completed this questionnaire to estimate F&V among their 5- and 6-year-old children. Miller, Moore & Kral. J Nutr Educ Behav, in press Intake of Fruits and Vegetables: Mother Child Associations r = 0.85; P < Miller, Moore & Kral. J Nutr Educ Behav, in press Majority of Children and Mothers did not Meet F&V Recommendations Children Food Fruits (servings/day) Vegetables (servings/day) Mothers Fruits (servings/day) Vegetables (servings/day) Intake (mean ± SEM; 95% CI) % who met USDA recommendations ± 0.4 (1.9, 3.5) ± 0.5 (2.4, 4.3) ± 0.4 (1.8, 3.6) ± 0.7 (3.7, 6.6) 41 Miller, Moore & Kral. J Nutr Educ Behav, in press 8

9 Child F&V Intake: Associations with Child Weight Status Overweight and obese children, on average, consumed 3 fewer servings of F&V per day than normal-weight children (P = 0.02). The odds of being overweight or obese was 7.3 times higher for children who did not meet the recommendations for F&V compared to children who met the recommendations (P = 0.08). Miller, Moore & Kral. J Nutr Educ Behav, in press Fruit and Vegetable Consumption: A Family Effort Efforts to increase F&V consumption in young children should be extended beyond the level of the individual child. Interventions may have greater impact if F&V are made available in the home and are consumed by mothers or other family members in the household. Interventions targeting F&V consumption may help children learn to substitute F&V for more energy-dense foods, which may have a protective effect against excessive weight gain. Eating in the Absence of Hunger: A Risk Factor for Overeating? Eating in the absence of hunger (EAH) is a trait which refers to children s susceptibility to eating when satiated in response to the presence of palatable snacks. Lunch (ad libitum) Snack (ad libitum) 10 min Assessment of fullness Fisher and Birch, 32: ,

10 EAH and Child Eating and Weight Gain Outcome EAH shown to be Energy intake Associated with increased short-term energy intake 1,2 Weight status Predictive of increased weight gain and risk of overweight in children 5,6 Stability Stable over time during early childhood 3,4 Parent feeding practices Heritability Heritable 6 Increased in children whose parents use restrictive feeding practices and increased monitoring 4,7 1 Fisher & Birch, Am J Clin Nutr, 69, , 1999; 2 Fisher & Birch, J Am Diet Assoc, 100, , 2000; 3 Fisher & Birch, Am J Clin Nutr, 76, , 2002; 4 Birch et al., Am J Clin Nutr, 78, , 2003; 5 Fisher & Birch, Am J Clin Nutr, 76, , 2002; 6 Fisher et al., Obesity, 15, , 2007; 7 Fisher & Birch, Appetite, 32, , Familial Transmission of EAH Degree of maternal disinhibition (eating in response to external or emotional stimuli) shown to be related to daughters EAH and weight-forheight 1. Familial correlations for disinhibition shown to be highest between mother and daughter 2. Disinhibition shown to be heritable 3. 1 Cutting et al., Am J Clin Nutr, 69, , 1999; 2 Provencher et al., Obesity Research, 13, , 2005; 4 Steinle et al., Am J Clin Nutr, 75, , 2002 Portion Size: Strategies to Moderate Energy Intake 10

11 Portion Size Effects on Intake in Children Increasing the portion size of energy-dense main entrées significantly increases intake in children (Fisher & Kral, 2008). Rolls, Engell & Birch, J Am Diet Assoc, 100, , 2000 Intake-Moderating Effects of Having Children Self-Serve Themselves Preschool-aged children were served a reference (125g / 175g) or large (250g / 350g) portion of mac & cheese, or they were instructed to serve themselves from a large serving bowl (250g / 350g) by American Society for Nutrition Children consumed 25% less of the entrée when allowed to serve themselves than when served the large portion by study staff. Orlet Fisher, Rolls & Birch, Am J Clin Nutr, 77: , 2003 Fruits and Vegetables Fruits and vegetables (F&V) not only provide essential nutrients, but they may also play a role in the regulation of energy intake. Increased intake of F&V shown to help reduce weight in obese children in family-based behavioral weight control programs (Epstein et al., 2001; Epstein et al., 2008). It is possible that increasing the amount of F&V served to children at a meal may not only increase intake of those foods, but may also displace the consumption of more energy-dense foods. 11

12 Specific Aims 1. To examine the effects of doubling the portion size of F&V side dishes on children s intake of F&V at a meal. 2. To determine how varying the portion size of F&V side dishes at a meal affects intake from a main entrée and total energy intake, and whether this effect varies among children as a function of their weight status. Study Design and Methods Child participants included 43 boys and girls, 5 to 6 years of age, with a range in body weight (37% of children had a BMI-for-age 85 th percentile). Child participants consumed dinner at our Center once a week for 2 weeks. On each test day, the same foods were served for dinner, but the portion size of 3 F&V side dishes was doubled. On the day of the test session, parents were instructed to have their child consume a typical lunch and an afternoon snack (if desired) and not consume any foods or beverages (except water) after 3:00PM. Experimental Meal 12

13 Food and Energy Intake at Dinner * * Kral et al, Obesity, 18, , 2010 Trend for Weight Status-by-Portion Size Interaction on Combined F&V Intake 19.8 ± 12.3g 57.8 ± 16.1g + 38% + 54% - 28% + 59% Weight status*portion size: P = 0.07 Kral et al, Obesity, 18, , 2010 Using Portion Size Strategically to Promote F&V Intake in Children Modifications in the portion size of a fruit side dish can have a substantial impact on children s fruit intake. Increased fruit intake in turn can modify children s intake from a more energy-dense entrée. Using portion size to promote vegetable intake is more challenging and may require enhancing the palatability or combining the vegetables with more preferred foods. 13

14 Combining Vegetables With More Preferred Foods Energy density (ED; kcal/g) of a pasta entrée was reduced by decreasing amount of cheese and substituting low fat cheeses and increasing amount of pureed tomatoes, broccoli, and cauliflower. Decreasing the ED of entrée by 25% significantly reduced energy intake from entrée by 25% (63 kcal) in 3- to 5-yearold children while increasing children s vegetable intake at lunch by half a serving of vegetables. Leahy et al., Obesity, 16, , 2008 Early Childhood A Critical Developmental Period First years of life are a critical developmental period during which many of children s food preferences and eating behaviors are being shaped. Parents, and mothers in particular, play an important role in shaping children s flavor preferences and eating behaviors: Importance of maternal diet (flavor learning in utero and during breastfeeding) Role models for healthy eating Early Childhood A Critical Developmental Period Importance of early home food environment: Make healthy foods available and easily accessible to children in the home Provide age-appropriate portion sizes at home and away-from home Serve larger portions of healthy foods Mix healthy foods with more preferred foods (lower their energy density) Importance of child feeding practices: Provide opportunities for children to repeatedly taste novel (healthy) foods Discourage restrictive or coercive feeding practices 14

15 Acknowledgments Collaborators Myles Faith, PhD Reneé Moore, PhD Paige Miller, PhD Jennifer Fisher, PhD Research Coordinators Erin Rauh April Kabay Collaborators Barbara J. Rolls, PhD Mickey Stunkard, MD Virginia Stallings, MD Robert Berkowitz, MD Students Anne Peschel Kaila Queen Funding Sources NIH, The Obesity Society 15