"Over-control of eating leads to fat children, study warns", NYT, 10 Nov 94, p. A10. "Parents' and children's adiposity and eating style", S. L. Johnson and L. L. Birch, Pediatrics, Nov 1994, Vol. 94, No. 5, pp. 653-661. 1. The subjects were 77 3-5-year-old children who attended preschool on the University of Illinois at Urbana-Champaign campus. Their parents also participated in the experiment. (journal, pg. 653, 2nd paragraph) 2. a) Children completed controlled, two-part meals used to estimate their ability to adjust food intake in response to changes in caloric density of the diet. The first part of the meal (the treatment) consisted of either a high-calorie or low-calorie drink. Treatments were assigned so that one half of the children consumed the high-calorie drink on the first day and the other half consumed the low-calorie drink. Two days later, the children received the other treatment. (p. 655, column 1, paragraph 1) b) In addition to either the high or low-calorie drink, each child also had another meal later in the day. The response measurement was the total amount of calories that the child consumed during that day's experiment. Because each child took part in the experiment on two different days (one with the high-calorie drink and the other with the low-calorie drink), a measure called COMPX was used to see how able each child was at regulating calories. (p. 655, column 1, paragraph 1) The range of values in this experiment was from -80% to 230%. A value of -50% means that a person will take in a smaller amount of food during the lunch when they have the low-calorie drink as a snack. A value of 0% means that a person eats the same amount of food regardless of which drink the child initially had. A value of 50% means that a child will eat more during lunch when the initial drink was low-calorie, low-calorie, but still, the child doen't compensate completely for the difference in caloric intake. A value of 100% means that the child compensates for a low-calorie drink by eating more during lunch so that the net caloric intake with both treatments is the same. (p. 655, column 2, paragraph 3) c) Each child participated in one pair of consumption trials; a trial pair consisted of 2 test days. On the first day of the trial, children were asked to drink the high- or low-calorie juice as a first course; twenty minutes later the children were given all they could eat of a variety of foods. (p. 655, column 1, paragraph 1) 3. The mean percentage compensation (COMPX), which reflects the children's responsiveness to caloric density of the diet, is 45%. The mean for boys was 55% and the mean for girls was 35%. (p. 655, column 2, paragraph 3) This means that boys were slightly better at regulating their caloric intake. All three graphs in Fig. 1 show the distributions of COMPX values--one graph includes boys only, another graph included girls only, and the large graph includes both boys and girls. The graph for boys doesn't really peak anywhere; thus a lot of variation exists in the scores that boys received on the COMPX. For girls, a clear peak is seen on the graph, so there is less variation. The large graph is a combination of the two other ones, and appears to have a slight left-hand tail. Summary statistics are found in Table 1, page 656. The mean +- the SE for the total group is 46.2% +/- 5.7%. For the males, it was 57.1% +/- 9.5%, and for the females it was 36.0% +/- 6.8%. Note that the SE is smallest when looking at both males and females together. The 3-D effect makes the information hard to gather because exact values on the y-axis are difficult to measure. 4. Yes. According to p. 653, "An eating index, reflecting children's precision in the ability to regulate energy intake, was correlated to children's anthropometric measures. These correlations provided evidence for a relation between children's body fat stores and their responsiveness to caloric density cues: Pearson correlation coefficients revealed that children with greater body fat stores were less able to regulate energy intake accurately." 5. Parents were asked to complete Stunkard and Messick's Three-Factor Eating Questionaire, which assesses dietary restraint, disinhibition, and perceived hunger. The researchers also recorded the sex, height, weight, triceps and subscapula skinfold thickness of the children. (p. 655, column 1, paragraphs 4 and 5) 6. The information used to predict response measurement is parental control of children's eating habits. More specifically, it was found that the correlation between the COMPX and parental control was strongest for the mothers' control of the children's eating habits. (p. 657, column 2, 1st paragraph) An experiment that could be used would be to control the children's food intake during the experiment, and find out if in subsequent tests the child is not as good at self-regulation of calories. Also, and experiment similar to that performed on the children can be performed on the parents, so see if there is a correlation between the COMPX scores of children and parents. 7. Mothers who indicated that they were controlling in their child-feeding practices had children who were less responsive to caloric density cues than less-controlling mothers. This was shown with lower COMPX scores. (p. 657, column 2, 1st paragraph) However, the title of the newpaper article may be too strong a statement, as it suggests that the controlling factor determines if a child is fat or not, when in fact the study's primary conclusion was that the controlling factor determines how well a child can regulate calories. The conclusions of the observational part of the study are accurately represented, but the newpaper article never really addresses how able the children are at self-regulation of calories. Since the average COMPX score is around 50%, this means that the children tend to consume more calories when given the low-calorie drink, but still don't consume enough calories to compensate for the loss in calories due to the switch from the high- to low-calorie drink.