Hypokinesia or low level of physical activity typical for the modern way of living, together with the consumed calories that cannot be burnt, lead to the increased weight which is above the average weight for a particular person. The presence of obesity from the day of birth to the old age is increasing in the world, and it may be stated that it is increasing in Serbia as well. The aim of this research is to establish the difference between height-weight relations and nourishment of seven-year-old pupils, measured in 1988 and 2008. The sample comprised primary school pupils, 7 years of age, from Nis, measured in 1988 and 2008. The number of examinees was 524, 257 boys measured in 1988, 91 boys measured in 2008, 91 girls measured in 1988, 85 girls measured in 2008. The results of this research showed that male pupils measured in 1988 had, statistically significan lower body weight, body mass index, average volume of the chest, skin folds, and had lower levels of fat in the body. Female pupils measured in 1988 had lower values of height, weight, body mass index, average chest volume, skin folds and lower levels of fat. The percentage of normally fed pupils measured in 1988 was 88.3%, while the percentage of those measured in 2008 was 59.3%. The relationship between 1988 and 2008 is 92.3% to 56.5%, in female pupils. The number of obese male and female pupils was significantly increased in 2008.
