- Click here for explanation of classification scheme.

To prospectively assess many of the established and hypothesized risk factors for the development of childhood overweight.

• (Eligibility described in journal article: Hammer LD, Bryson S, Agras WS. Development of feeding practices during the first 5 years of life. Arch Pediatr Adolesc Med 199;153;189-94)
• Infants were eligible for participation if they were born at term (>37 weeks' gestational age) and had Apgar scores of at least 7 at 1 and 5 minutes after birth.
• At risk for overweight: above the 85^th percentile of BMI.
• Overweight: above the 95^th percentile of BMI.

Any congenital abnormalities or experienced any illness during newborn hospitalization.

Recruitment

Newborn infants and their parents recruited from well newborn nurseries at a university hospital, community hospital, and a health maintenance organization in the San Francisco Bay Area.

Design

The following data were collected:

• parental height and weight,
• infant weight and length,
• infancy feeding behaviors (sucking pressure and burst duration),
• early infant weight gain,
• maternal expectations of infant feeding (maternal pushiness) and body habitus (images of male & female infants from thin to plump),
• parent/infant feeding practices,
• parent eating behaviors (dietary restraint, hunger, and disinhibition),
• maternal return to work,
• childhood eating behaviors (picky eating, rapid eating, tantrums over food, non-nutritive food uses),
• 24 hour child caloric intake,
• child activity level and duration of TV viewing,
• child temperament,
• sleep time,
• maternal weight gain (over a five year period, from infant’s age of 0.5 to 5.5 years),
• parent’s concern about child’s weight (underweight and overweight), parent feeding behaviors (non-nutritive food uses and use of food limits),
• laboratory measures of parental behaviors,
• parenting behaviors (authoritarian, authoritative, permissive styles). 

Parent behaviors in feeding their children included non-nutritive food uses and the use of food limits, by using an annual questionnaire at ages 2 through 5 years.  The scales for parental concerns and nonnutritive food uses were stable over that period, and the results were averaged; however, the measure of food limits varied across time and hence each year was entered separately.

Statistical Analysis

Logistic regression (association between each possible risk factor and the binary outcome above or below the 85^th percentile of BMI at 9.5 years), stepwise regression (to understand the mechanism through which low parental concern about their child’s weight may affect overweight), recursive partitioning analysis (to identify subgroups with a differential risk of having a BMI =85^th percentile at 9.5 years of age)

Timing of Measurements

Infant weight assessed at 2 weeks of age and six months, infant sucking behavior at 2 and 4 weeks, parent/infant feeding practices collected for the first 3 days of each month until the child was weaned from both breast and bottle, childhood eating behaviors at ages 2, 3, 4, and 5, child temperment at age 5, maternal weight and height at the 5.5 year visit, caloric intake, child activity and laboratory measures of parental behaviors at ages 3 and 5, and sleep time, parent feeding behaviors and parent concerns about child's weight at ages 2, 3, 4, and 5. Parental Attitudes: The parental authority questionnaire was used to measure parenting style, including authoritarian, authoritative, and permissive styles of behavior (Buri’s questionnaire). Parent concerns about child’s weight (overweight & underweight) were assessed by annual questionnaire at ages 2 through 5 years – this is the extent of the explanation of the questionnaire. Data were not separated by gender of child.

Dependent Variables

Body mass index

Independent Variables

Child’s temperament, activity level, hours of sleep, parental concerns about thinness, parental overweight, early feeding measures, early growth, maternal attitudes

Initial N: 216

Attrition (final N): 150 (74 boys, 76 girls)

Age: Birth to 5 years

Ethnicity: Assessed but not stated

Anthropometrics: Of the 150 children, 38 (25.3%) were above the 85^th percentile of BMI at 9.5 years of age, including 14 (9.0%) above the 95^th percentile.

Location: San Francisco Bay Area

Predicting Child Overweight

Strongest relation was with parental BMI (W=13.7, p<0.001), which was mediated by temperament of the child assessed as a combination of approach and impulsivity (W=6.6, p<0.01). This factor is correlated with an active personality and anger/frustration, indicating highly emotional behavior.

The remaining risk factors were:

• low parental concern about their child’s thinness (in other words, the parents are not worried that their child was too thin) (W=5.2, p<0.02);
• children with persistent tantrums over food (W=9.3, p<0.002);
• children’s hours of sleep at ages 3 to 4 years (W=6.6, p<0.01).

Explaining Parental Concern

We noted above that the authors identified one aspect of parental concern that was associated with (though, not in a causal manner) childhood overweight: low concern over thinness. A clearer statement of this variable would be: parents not worried about their child being underweight.

The authors examined the factors associated with different kinds (and levels) of parental concern about their child's weight. Four possibilities for parental concern were examined:

1. High concern over child underweight (that is, worried that the child was too thin)
2. Low concern over child underweight (that is, not worried about underweight)
3. Low concern over child overweight (that is, not worried about overweight)
4. High concern over child overweight (that is, worried that the child was too fat)

Of the four possible types and levels of concern, only #2 (low concern about child being underweight) was found to be associated with child overweight. So, the authors examined what factors seemed to be associated with this type of parental concern.

The predictors of low concern about child being underweight were:

• weight gain in the first 6 months of life (B= -0.3, t(118)= -3.6, p=0.001) (strongest predictor),
• followed by birth weight (B= 0.24, t(118)= -2.8, p=0.006),
• maternal preference for a thin baby (B= 0.19, t(118)= 2.8, p=0.006).

Low concerns about thinness seemed to reflect a parent with a preference for a thin child faced with a developmental pattern of higher birth weight, rapid weight gain in the first 6 months of life, and as show by the correlates of this risk factor, an eating pattern comprising rapid eating and a high interest in food. 

In other words, if the parent wants a thin child, but has a big baby who gains weight quickly, chances are the parent is not going to be worried that their child is underweight.

Other Factors Associated with Child Overweight

Tantrums over food were positively related to overweight, with persistent tantrums about 3 times more likely to occur in those who would become overweight. Although 82% of children had such tantrums at some time during childhood, only 19% had persistent tantrums reported annually from 2 through 5 years of age.

Hours of sleep reported annually from 3 through 5 years were negatively related with overweight; children who were to become overweight were reported to sleep about 30 minutes less on average than those who would remain normal weight. This difference was almost entirely due to shorter daytime sleep, with only 5 minutes’ difference in night-time sleep.

A child with an overweight/obese parent had a 48.1% chance of becoming overweight obese, whereas a child with normal weight parents had a 13.3% chance of becoming overweight or obese.

For parents who were not overweight, if their child had persistent temper tantrums over food during years 2 through 5, 31.2% would become overweight compared with 9.8% for those without tantrums.

For children with overweight parents who were not worried that their child was underweight, reflecting the developmental pattern described above, 62.9% would become overweight/obese compared with 33.6% for those without this temperamental profile.

Parental attitudes toward their child’s weight may lead to behaviors that increase the risk of their child becoming overweight.

Child’s behaviors such as temper tantrums and the behavior difficulties posed by the highly emotional child, which in turn may lead to overfeeding, are amenable to parental counseling. The findings of this study suggest that at-risk children and their parents may be identifiable in the first few years of a child’s life, affording the opportunity for early preventive interventions.

Government:

NICHD

Strengths:

• Prospective design of 10 years

Limitations:

• Authors' method of gathering information on parental attitudes does not indicate that parental attitudes (such as being worried about underweight) are prior to child weight changes. Thus, the statement that parental attitudes "may lead" to childhood overweight are out of place. Indeed, in explaining parental attitudes it is child weight gain patterns that influence parental attitudes and not the other way around.
• Small sample size.
• Level of parental education is higher than that of the general population.
• Percentage of minorities is lower than that of the general population.
• Some of the critical assessments (i.e. childhood personality attributes) were obtained by parental report, possibly biasing the results of this assessment.
• A substantial number of the original participants dropped out by 9.5 years of age or provided incomplete data. Those who dropped out tended to be less well educated than those who did not, again potentially biasing the results.

Other comments

Control variables not clearly stated, if assessed.