EDITORIAL

The scientific evidence generated in recent years has documented the highly important role of nutrition in health. Particularly in countries as ours, the concern over nutrition has evolved from an emphasis on problems of malnutrition to the study of problems related with poor nutrition –due to both malnutrition and excess nutrition– and its relation with non-transmissible chronic diseases.

In Mexico, a significant number of actions have been taken with respect to health and nutrition. The design and continued improvement of these actions would not be possible without the generation of information to identify the magnitude, distribution and trends of existing nutritional and health conditions. Such information is also necessary to evaluate the impact of the organized social response.

Our country has a recognized tradition of research in the area of nutrition, In general, there are three periods in the study of nutrition and health that can be identified. First, since the 19^th century we can find detailed studies of specific populations that suggest that malnutrition was the principal nutritional problem until the 1960s, although they do not describe the conditions of the general population. During the second period, between the 1960s until the latter 1980s, we find surveys with larger sample sizes and without probabilistic designs, in addition to detailed studies. As in the previous period, these studies stress the significance of malnutrition in Mexico. Beginning in 1988, information about nutritional status has been generated using nationally representative surveys conducted in 1988, 1999 and, more recently, in 2006. These surveys have documented important changes in the nutritional situation of the Mexican population during the past two decades. Our country has experienced a decrease in the magnitude of problems related to malnutrition, especially among the poorest populations. Nevertheless, social lag continues to be a public health problem that has yet to be resolved. Meanwhile, problems of poor nutrition due to excess (overweight and obesity) are gaining more and more importance and have become one of the primary health problems the country faces; attention to this issue is, therefore, one of the highest priorities for Mexico's health sector.

The Mexican National Health and Nutrition Survey 2006 (ENSANUT 2006), which serves as a source of information for the works presented in this special issue, demonstrates great advances in national nutrition surveys since those of 1988 and 1999. This new survey shows, for the first time, information about nutritional status representative at the state level. In addition, it broadens the categories of information studied in previous surveys to include children, adolescents, and male and female adults.

The generation of scientific evidence must strictly follow methodological guidelines. Thus, the analyses of information conducted for the articles in this issue are examples of sophistication and adherence to the methodological standards for working with such information. And yet, scientific evidence can only have an impact on the design of health policies and programs if there is an adequate process for translating the knowledge. It will now be necessary to discuss the findings of this survey in order to generate specific public policies and programs to improve the nutritional and health conditions of the Mexican population.

Mauricio Hernández Ávila^*

* Vice Minister of Disease Prevention and Health Promotion. Ministry of Health. Mexico.