Tuesday, February 21, 2017

Validation of the Fitbit One for assessing physical activity

Accelerometer-based wearables can provide the user with real-time feedback through the device's interface and the mobile platforms, and this may help to encourage people to get and remain physically active. However, meaningful feedback can only be provided if such wearables validly measure physical activity levels. Very few studies have focussed on the minute-by-minute validity of wearables, which is essential for high quality real-time feedback. In a study just published online by the Journal Medicine & Science in Exercise & Sports we aimed aims to assess the validity of the Fitbit One compared to what is considered a 'gold standard' for assessing physical activity, i.e. the ActiGraph GT3x+. We looked at validity in measuring steps taken, and time spent in moderate, vigorous, and moderate-vigorous physical activity) among young adults using traditional time intervals (i.e., days) and smaller time intervals (i.e., minutes, hours).
Thirty-four healthy young adults participated and wore the ActiGraph GT3x+ and a Fitbit One for one week. As compared to ActiGraph the Fitbit One systematically overestimated physical activity for all aggregation levels: on average 0.82 steps per minute, 45 steps per hour, and 677 steps per day. Strong and significant associations were found between ActiGraph and Fitbit results for steps taken, and weaker but statistically significant associations were found for minutes spent in moderate, vigorous and moderate-vigorous physical activity for all time intervals.
We conclude that although the Fitbit One overestimates the step activity compared to the ActiGraph, it can be considered a valid device to assess step activity also for real-time minute-by-minute self-monitoring. However, agreement and correlation between ActiGraph and Fitbit One regarding time spent in moderate, vigorous and moderate-vigorous physical activity were lower.

Friday, February 17, 2017

Measurement of availability and accessibility of food among youth

Availability and accessibility of foods are regarded as important determinants of food choice and nutrition behavior, because it makes sense that people -children as well as adults- tend to eat what is easily available and accessible to them. To study the relevance of availability and accessibility, good, i.e. valid and reliable, measures of availability and accessibility are needed. In a paper just published in the International Journal of Behavioral Nutrition & Physical Activity, we present and discuss the results of a systematic review of the psychometric properties of measures of food availability and accessibility among youth. A secondary objective was to assess how availability and accessibility were conceptualized in the included studies.
We reviewed studies studies published between January 2010 and March 2016 that reported on at least one psychometric property of a measure of availability and/or accessibility of food among youth were included.
A total of 20 studies were included. While 16 studies included measures of food availability, three included measures of both availability and accessibility; one study included a measure of accessibility only. Different conceptualizations of availability and accessibility were used across the studies. The measures aimed at assessing availability and/or accessibility in the home environment, the school, stores, childcare/early care and education services and restaurants. Most studies followed systematic steps in the development of the measures. The most common psychometrics tested for these measures were test-retest reliability and criterion validity. The majority of the measures had satisfactory evidence of reliability and/or validity. None of the included studies assessed the responsiveness of the measures.

Tuesday, February 14, 2017

Screentime and soft drinks

Extensive sedentary time, i.e. (uninterrupted) sitting for too long, and especially sitting in from of TV's or other 'screens' have been associated with unfavorable cardiometabolic health. Apart from sitting too long itself, TV time may be accompanied by snacking and sugary drinks, which may lead to excess calorie intake, unnecessary weight gain, and eventually to overweight and obesity. In a study just published in the journal PLOS One we explored if children who spend more time sitting behind or before 'screens' TV, PC, tablet et cetera, i.e. 'screen-based sedentary behavior' drink more sugar-sweetened soft drinks. The study also assessed if such an association between screen-based sitting time and sugary drinks intakes differed according to level of education of the parents.
Data were collected from 7886 children participating in the EuropeaN Energy balance Research to prevent excessive weight Gain among Youth (ENERGY) survey conducted in eight European countries.
In six of the eight included countries, children who reported to watch more TV also reported to drink more soft drinks, but there was no significant association between computer use and soft drink consumption in six of the eight countries. In Norway and Hungary, the association between TV viewing and soft drinks was stronger for children from lower educated parents.

Tuesday, February 7, 2017

The DONE framework for determinants of nutrition and eating

The question of which factors drive human eating and nutrition is a key issue in many branches of science, and is of utmost importance to inform health promotion interventions and policies. In a paper just published in PLOS One, we describe the creation, evaluation, and updating of an interdisciplinary, interactive, and evolving “framework 2.0” of Determinants Of Nutrition and Eating (DONE). This endeavor was part of the DEDIPAC (determinants of diet and physical activity) joint action within the Healthy Diet, Healthy Life European joint programming initiative. A similar exercise was done and already published for sedentary behavior (the systems of sedentary behavior (SOS) framework). The DONE framework was created by an interdisciplinary workgroup in a multiphase, multimethod process. Modifiability, relationship strength, and population-level effect of the determinants were rated to identify areas of priority for research and interventions. External experts positively evaluated the usefulness, comprehensiveness, and quality of the DONE framework. An approach to continue updating the framework with the help of experts was piloted. The DONE framework can be freely accessed via the lead university for DONE, i.e. university of Konstanz in Germany,
and used in a highly flexible manner: determinants can be sorted, filtered and visualized for both very specific research questions as well as more general queries. The dynamic nature of the framework allows it to evolve as experts can continually add new determinants and ratings. We anticipate this framework will be useful for research prioritization and intervention development.

Saturday, February 4, 2017

Built environment and cycling for transport in Europe

In a cross-sectional study just published in the journal Health & Place with Lieze Mertens from Ghent University as first author, we explored which observed built environmental factors were associated with cycling for transport among adults in five urban regions across Europe. This study was part of the SPOTLIGHT (sustainable prevention of obesity through integrated strategies) project, that The build environment was observed with a virtual neighbourhood audit tool using Google street view, that was specifically developed for this study. We further explored if the association of build
environment characteristics with cycling for transport depended on such factors as age, gender, socio-economic status and country/urban region. The results showed that people living in neighbourhoods with a preponderance of speed limits below 30 km/h, many bicycle lanes, with less traffic calming devices, and more trees; but also with more litter and parked cars on the road were more likely to cycle for transport than people living in areas with lower prevalence of these factors. The results suggest that reducing speed limits for motorized vehicles and the provision of more bicycle lanes may help to facilitate cycling for transport in urban regions across Europe. Hardly any evidence was found that the associations were different between men and women, or according to age or socio-economic status.

Sunday, January 29, 2017

Exploring health education with midwives

In a study just published -with Ruth Baron as first author- in the journal Midwifery we explored the experiences, wishes and needs of pregnant women with respect to health education in primary care with midwives. We used qualitative semi-structured interviews, using thematic analysis and constant comparison. Twenty-two pregnant women in midwife-led primary care, varying in socio-demographic characteristics, weeks of pregnancy and region of residence in the Netherlands, were interviewed between April and December 2013.
The women considered midwives to be the designated health caregivers for providing prenatal health education, and generally appreciated the information they had received from their midwives. Some women, however, believed the amount of verbal health information was insufficient; others that there was too much written information. Many women still had questions and expressed uncertainties regarding various health issues, especially regarding weight gain, alcohol, and physical activity. Women felt that important qualities for midwives underlying health education, were making them feel at ease and building a relationship of trust with them.
Health education was highly appreciated by women in general, suggesting that midwives should err on the side of providing too much verbal information, as opposed to too little. A more pro-active approach with information provision may be of value not only to those with a clear desire for more information, but also to those who are unsure of what information they may be missing. As midwives are the principal health care providers throughout pregnancy,they should ideally emphasize their availability for questions between prenatal visits.

Monday, December 12, 2016

High Sedentary Time and Little Physical Activity in 4 countries in Europe

The objective of a study just published in Sports Medicine -with Anne Loyen as first author- was to pool, harmonise and re-analyse national accelerometer data from adults in four European countries in order to describe population levels of sedentary time and physical inactivity.
ActiGraph accelerometer count data from 9509 participants of five cross-sectional studies -in England, Portugal, Norway and Sweden- were centrally processed using the same algorithms. Multivariable logistic regression analyses were conducted to study the associations of sedentary time and physical inactivity with sex, age, weight status and educational level, in both the pooled sample and the separate study samples.
On average, participants were sedentary for 530 min/day, and accumulated 36 min/day of moderate to vigorous intensity physical activity. Twenty-three percent accumulated more than 10 h of sedentary time/day, and 72% did not meet the physical activity recommendations. Nine percent of all participants were classified as high sedentary and low active. Participants from Norway showed the highest levels of sedentary time, while participants from England were the least physically active. Age and weight status were positively associated with sedentary time and not meeting the physical activity recommendations. Men and higher-educated people were more likely to be highly sedentary, while women and lower-educated people were more likely to be inactive.
In conclusion, w
e found high levels of sedentary time and physical inactivity in four European countries. Older people and obese people were most likely to display these behaviours and thus deserve special attention in interventions and policy planning. In order to monitor these behaviours, accelerometer-based cross-European surveillance is recommended.