This study considered the growth status and physical fitness of primary school children in a rural and an urban community in the Valley of Oaxaca, southern Mexico, in 1999-2000. The prevalence of growth stunting, wasting, and overweight and obesity were also considered. The sample included 700 school children 6 to 13 years of age, 361 from the rural community (177 males, 184 females) and 339 from the urban community (173 males, 166 females). Anthropometric dimensions included body size, segment lengths, skeletal breadths, limb circumferences and skinfolds. The body mass index (BMI), leg length, arm and calf muscle circumferences, sum of skinfolds, and a trunk/extremity skinfold ratio were derived. Physical fitness items included motor- and health-related tests: right and left grip strength (muscular strength), 35 yard dash (32.3 meters, speed), standing long jump (explosive power), sit-and-reach (flexibility), timed sit-ups (30 seconds, abdominal strength and endurance), and a distance run (8 minutes in grades 1-3 and 12 minutes in grades 4-6, cardiovascular endurance).

Height, weight, sitting height, estimated leg length and skeletal breadths on the trunk were significantly larger in urban than in rural school children. The BMI, sitting height/stature ratio, skeletal breadths on the extremities, limb and estimated limb muscle circumferences, subcutaneous fatness and relative fat distribution did not consistently differ by age group and sex between urban and rural children. Urban children tended to perform better in the sit and reach, sit-ups and standing long jump, but results were not consistently significant. Rural children 6-9 years tended to perform better in the dash. There were no urban-rural differences in grip strength, but strength per unit body mass was greater in rural children. Rural children in grades 1-3 performed better in the distance run, but results in older children were not consistent.

The prevalence of stunting was about twice as great in rural than in urban children, but the prevalence of wasting was very low in both communities. The prevalence of overweight was significantly greater in urban than in rural children, but he prevalence of obesity was low.
Rural children, boys more than girls, reported more frequent daily participation in household-related activities classified as moderate and moderate-to-vigorous in intensity compared to urban children. Urban boys reported more household-related activities of light or very light intensity. Urban and rural girls did not differ in reported frequencies of daily household activities classified of light and very light intensity. Urban children reported more diversity in diet, specifically at breakfast and dinner, than rural children. Animal protein represented in meats and meat derivatives were rather limited in the diets of rural children.

The results of the comparisons of growth status, physical fitness, daily activities and diet of urban and rural primary school children reflect, to a large extent, the contrast of living conditions and access to resources in the urban and rural communities.