Physical activity and sedentary behavior in Belgium (BNFCS2014): design, methods and expected outcomes

Background

There is strong evidence to indicate that regular moderate intensity physical activity is associated with health benefits. Furthermore, sedentary behavior has been related with an increased risk for all-cause mortality. The accurate measurement of physical activity and sedentary behavior is therefore vital to evaluate their health impact and provide evidence for the development of public health recommendations. This paper describes the methodology used for assessing physical activity and sedentary behavior in the Belgian population in the context of the Belgian National Food Consumption Survey 2014 (BNFCS2014).

Results

Data about physical activity and sedentary behavior were collected as part of the cross-sectional BNFCS2014 between February 2014 and May 2015. A nationally-representative sample of children (3–9 years) and adolescents (10–17 years) were asked to wear an accelerometer (Actigraph® GT3X) during their waking hours for 7 consecutive days. Data were recorded in 15-second epochs and respondents with at least 2 valid week days (i.e., 10 h of wear-time) and 1 valid week-end day (i.e., 8 h of wear-time) were retained for the analyses. The Evenson cut points were used to assess the time spent in each physical activity intensity level: sedentary, low, moderate and vigorous. Complementary, diaries were provided to register the activities performed when the accelerometer was removed; these activities were added to the measures provided by the accelerometers. In addition, age-specific self-reported questionnaires (ToyBox and FPAQ) were completed to provide contextual information about the type of activities performed. Due to financial constraints, physical activity in adults (18–64 years) was assessed and described through the self-reported International Physical Activity Questionnaire (IPAQ long version) only.

Conclusion

Data were collected in the context of the BNFCS2014 to provide a comprehensive picture of the physical activity and sedentary behavior in the Belgian population, with a special focus on children (3–9 years) and adolescents (10–17 years). Levels of physical activity and sedentary behavior can be compared to international guidelines and analyzed according to several background variables, such as age, gender, Body Mass Index, education level and region. Such results are aimed to underpin future policies in the field of physical activity.

Protocol of the Belgian food consumption survey 2014: objectives, design and methods

Background

Dietary patterns are one of the major determinants as far as health and burden of disease is concerned. Food consumption data are essential to evaluate and develop nutrition and food safety policies. The last national food consumption survey in Belgium took place in 2004 among the Belgian population aged 15 years and older. Since dietary habits are prone to change over time a new Belgian National Food Consumption Survey (BNFCS2014) was conducted in 2014–2015.

Methods

The BNFCS2014 is a cross-sectional study. A representative sample (n = 3200) of the Belgian population aged 3 to 64 years old was randomly selected from the National Population Register following a multistage stratified sampling procedure. Data collection was divided equally over the four seasons and days of the week in order to incorporate seasonal effects and day-to-day variation in food intake. Information on food intake was collected in adults with two non-consecutive 24-h dietary recalls (using the GloboDiet® software). In children food intake was collected with two non-consecutive one-day food diaries followed by a completion interview with GloboDiet. Additional data on socio-demographic characteristics, eating habits, lifestyle, food safety (at household level), physical activity and sedentary behaviour were collected with a face-to-face questionnaire using a computer-assisted personal interviewing technique. In the time between the two visits, participants were asked to complete a self-administered food frequency questionnaire and health questionnaire. Height, weight and waist circumference were measured. In addition, children and adolescents were asked to wear an accelerometer and keep a logbook for seven consecutive days to objectively measure physical activity and sedentary behaviour.

Conclusion

The main objective of the BNFCS2014 is to evaluate the habitual food, energy and nutrient intake in the Belgian population and to compare these with recommendations from the national dietary guidelines. A second objective is to monitor eating habits and food safety aspects of the food consumption in Belgium. The results of this dietary monitoring survey, together with the information on the level of physical activity, may underpin future nutrition, food safety and physical activity policies at national and European level.