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close this bookActivity, Energy Expenditure and Energy Requirements of Infants and Children (International Dietary Energy Consultative Group - IDECG, 1989, 412 pages)
close this folderThe relationship between undernutrition, activity levels and development in young children
close this folder5. Preliminary findings from a study of nutritional supplementation and psychosocial stimulation of stunted children
View the document(introductory text...)
View the document5.1. Developmental levels
View the document5.2. Activity levels
View the document5.3. Relationship between activity and development
View the document5.4. Dietary intakes
View the document5.5. Conclusions

5.2. Activity levels

The activity levels of a subsample of the children were observed. Seventy-eight of the stunted and 26 of the non-stunted children, all between 12 and 24 months of age, were studied. Time-motion methods, similar to those of TORUN (1984), were used. In this method, all activities likely to occur are listed, and a check is made every 10 minutes to indicate which ones occurred. The assumption is then made that equal time is spent in each activity which occurs in the period. Torun pointed out that this tends to increase the time apparently spent in the more vigorous activities. We also demonstrated this in the pilot phase. Therefore, we changed the recording interval to one minute, as this more closely approximates the actual timing.

The proportion of time spent in each activity was calculated for the whole observation period. Energy costs of the activities were then taken from values reported by TORUN and VITERI (1989) which were expressed as multiples of BMR. The data were expressed as the proportion of time spent in vigorous, moderate and light or sedentary activities, according to their estimated energy costs. In addition, an activity rating was calculated by multiplying the percent of time spent in each activity by its estimated energy cost and then summing the products. In the pilot phase, 10 children were observed for 3 days. The activity ratings on the 3 days were highly correlated (r = 0.81 to 0.96) and the mean activity ratings were not significantly different on the different days. The children in the main study were observed for 4 waking hours, from 9.30 a.m., for 2 weekdays, never more than 2 weeks apart. Further details of the method and interobserver reliabilities have been reported (MEEKS GARDNER et al., 1990). We also recorded whether certain other activities occurred in the child's environment. Examples of these are whether the child was in a crib or playpen or being held, and whether anyone was talking to or playing with him.

The stunted children spent more time in light activities (p < .001) and less time in moderate (p < .01) and vigorous activities (p < .01) than the non-stunted children (Table 5). The activity rating was significantly lower in the stunted group (mean 1.4, SD .1, p < .01) than in the non-stunted group (mean 1.5, SD .1), and the difference was not due to one group being carried or restrained more than the other. However, in terms of energy cost, the difference was small.

Table 5. Percentage of time spent in activity categories and the activity rating by group


Stunted

Non-stunted


n = 79

n = 26

Activity category

Mean

SD

Mean

SD

Light

78

9 ++

73

7

Moderate

21

8 +

25

7

Vigorous

1

2 +

2

2

Activity rating

1.4

0.1 +

1.5

0.1

+ p < .01
++ p < .001

In the pilot phase, we showed that observing for 4 waking hours gave very similar results to observing for all the waking time from 9.30 a.m. to 5.30 p.m. It is reasonable to assume that these data represent the activity levels of the children for at least this period of time. The amount of time the children slept, while the observers were present, was very similar in the two groups. Further, the mothers were asked how long their child slept the previous day, and again both groups reported very similar amounts (stunted mean 11.9, SD 1.3; non stunted 11.8, SD 1.4). The activity level increased significantly with age (r = .59 p < .001). It was not related to weight-for-height, sex or dietary intake data. The aetiology of the reduced activity in the stunted group was not therefore clearly related to reduced energy availability.