Background
Diet and nutrition are major determinants of health. The nutritional status of the population is an important indicator of the nation’s health. The Nutrition and Health Survey is essential to monitor nutrition and health status of the population and to inform policy making and program evaluation.
Taiwan launched the planning for national nutrition surveys since 1980. In 1980-81 and 1986-88, household surveys for dietary intake and children's physical development, as well as actual measuring and weighing of the food were conducted. Since 1993, the government has conducted a series of Nutrition and Health Survey in Taiwan. The protocol of the survey in 1993-1996 included 24-hour dietary recall of participants aged 13 to 64 and dietary habits of children aged 4-12. Target population of the surveys in the following years were senior citizens in 1990-2000, elementary school students in 2001-2002, children aged 0-6 and adults aged over 19 in 2005-2008, junior and senior high school students in 2010-2011, and elementary school students in 2012.
The Nutrition and Health Survey in Taiwan (NAHSIT) was initially managed and funded by the former Bureau of Food and Drug, Department of Health. The Health Promotion and Administration (HPA) took over the responsibility in 2013. A major redesign of the survey was undertaken in that year (2013) aiming to establish a stable and continuous monitoring system for health and nutritional status of the citizen. The current sampling design is featured with its national representative sampling design of the whole population for every single year and the data accumulated over years can potentially be city/county representative. The most recent wave of NAHSIT after the redesign was conducted during 2013-2016.
Aim of the Survey
The primary aim of NAHSIT is to establish a long-term, stable and regular monitoring system, which can monitor the national health and nutrition status. The data can be applied as a reference for nutrition and health policymaking.
Sampling Design
NAHSIT uses a multistage, stratified, clustered, probability sampling design to select participants represent for the civilian, non-institutionalized Taiwan population of all ages. Seasonal effects were taken into account by allocating data collection over the four seasons. A pseudo-Latin square design was used to allocate survey time for town-ship in order to balance the effects of season and year.
Survey method
Face to face interview is conducted in respondents’ homes. Health measurements are performed at an appropriate site in each township, some measurements are implemented in specially-designed and equipped mobile stations, which travel to locations throughout Taiwan.
Content of the Survey
Risk factors, those aspects of a person’s lifestyle, constitution, heredity, or environment that may increase the chances of developing a certain disease or condition, will be examined.
The diseases, medical conditions, and health indicators to be studied include:
1. Behavior indicators
● Diet behavior (nutrients, salt and ssbs intake)
● Diet belief
● Physical activity
● Weight control
● Using behavior of tobacco, alcohol, and betel nuts
2. Health outcome indicators
● Nutrition (vitamins and minerals)
● Obesity
● Body composition (muscle, body fat and bone density)
● Metabolic syndrome
● Cardiovascular disease (hypertension, Hyperlipidemia, heart disease)
● Anemia
● Diabetes
● Kidney disease
● Physical functioning
● Medical and Reproductive history
● Respiratory disease (asthma, chronic bronchitis, emphysema)
● Environmental exposure