Influence of dietary intervention on artificially increased activity in marginally undernourished Colombian boys.

Studies of the pattern of daily energy expenditure (EE), total daily energy expenditure (TDEE) and energy expended in activity (EAC) have been carried out in 14 nutritionally normal and 19 marginally malnourished, free-living boys 10-12 years of age using the minute-by-minute heart rate recording technique. Measurements were made during an ordinary school day and again about 6 months later under conditions of a summer day-camp where the activity levels were artificially increased by encouragement to participate in supervised sports activities and play. The morning and afternoon activities were separated by a dietary intervention in the form of a hot meal providing approximately 3.2 MJ (760 kcal). In the morning sessions of the day-camp the undernourished boys did not keep up with the control group by increasing their EE. However, for about 2 h following the noon meal, they did increase EE to levels comparable to the control group but again reduced their EE later in the afternoon and earlier than the control subjects. The data show an inability of undernourished boys to increase their activity which is positively affected for a short period by dietary intervention.