A comparison of the national nutrition surveys was carried out in both urban and rural areas and found that the nutritional status of children of less than five years showed a marked decrease in the prevalence of malnutrition on a national scale from 1988 to 1999 (SSA, 1988; Pérez Hidalgo, 1986; INNSZ, 1982;1990; INSP, 1999). The most recent data shows a reduction in stunting, underweight and wasting; on the other hand, there is an increase in the prevalence of overweight and obesity. In Mexico, nearly 1.8 million children less than five years are stunted, approximately 800 000 children are underweight and 213 000 children are wasted (INSP, 1999). In all the surveys, a polarization of the distribution of the nutrition problems in the country was observed. There is a high prevalence of malnutrition in the south and in the rural areas, with an increase in the prevalence of overweight and obesity in the north and in urban areas.
Among school-aged children (5 to 11 years) studied in 1999, the highest prevalence rates observed are those of overweight, obesity and stunting, for both genders (INSP, 1999). Women of reproductive age showed a higher prevalence rate for overweight and obesity compared to previous surveys (SSA, 1988; INSP; 1999).
According to the last survey, research on micronutrient deficiencies revealed that iron deficiency is the most widespread affecting mainly rural areas. The highest prevalence of iron deficiency was observed among the children less than five years and among pregnant women (INSP, 1999). The highest prevalence rates of vitamin A deficiency (serum retinol<<20µg/dL) and iodine deficiency (urinary iodine <100µg/L) were found in children under 12 years (23% and 9%, respectively). The main public health problems identified were obesity in women of reproductive age and anaemia in children less than five years of age and women of reproductive age.
The urban population in Mexico increased by 36% between 1965 and 2000, and it is estimated to represent over 82% of the population in the year 2030. The same tendency was observed in Dietary Energy Supplies which, in 1999-2001, largely covered average per person energy requirements. Access to food, and not food availability, is believed to be the main problem in Mexico. An estimated 44.7 million people live in poverty, that is to say half of the total population (CEPAL, 1999). The principal changes observed in the nutritional status of the population were reached through extension programmes to provide health care, in particular primary health care interventions including immunization, oral rehydration therapy, education, and food and health programmes, within the framework of government policy.