Long-term changes in dietary and food intake behaviour in the Diabetes Prevention Program Outcomes Study.

AIMS: To compare change in dietary intake, with an emphasis on food groups and food intake behaviour, over time across treatment arms in a diabetes prevention trial and to assess the differences in dietary intake among demographic groups within treatment arms. METHODS: Data are from the Diabetes Prevention Program and Diabetes Prevention Program Outcomes Study. Participants were randomized to a lifestyle intervention (n = 1079), metformin (n = 1073) or placebo (n = 1082) for an average of 3 years, after which the initial results regarding the benefits of the lifestyle intervention were released and all participants were offered a modified lifestyle intervention. Dietary intake was assessed using a food frequency questionnaire at baseline and at 1, 5, 6 and 9 years after randomization. RESULTS: Compared with the metformin and placebo arms, participants in the lifestyle arm maintained a lower total fat and saturated fat and a higher fibre intake up to 9 years after randomization and lower intakes of red meat and sweets were maintained for up to 5 years. Younger participants had higher intakes of poultry and lower intakes of fruits compared with their older counterparts, particularly in the lifestyle arm. Black participants tended to have lower dairy and higher poultry intakes compared with white and Hispanic participants. In the lifestyle arm, men tended to have higher grain, fruit and fish intakes than women. CONCLUSIONS: Changes in nutrient intake among participants in the lifestyle intervention were maintained for up to 9 years. Younger participants reported more unhealthy diets over time and thus may benefit from additional support to achieve and maintain dietary goals.

Self-administered questionnaire compared with interview to assess past-year physical activity.

PURPOSE: The Modifiable Activity Questionnaire (MAQ) is a physical activity questionnaire shown to be both valid and reliable and was initially designed to be interviewer-administered. After translation and adaptation into French, the objective of the study was to compare past-year physical activity data obtained by self-administration of this questionnaire and by interviewer-administration. METHODS: 84 subjects (22 men, 62 women, age 36-63 yr) enrolled in an ongoing prospective study in France (the SUpplementation en VItamines et Minéraux AntioXydants or SU.VI.MAX study) completed both versions of the questionnaire in a randomized order with a mean (SD) delay of 7.9 (5.8) d between the two modes. Past-year leisure and occupational physical activity were expressed as both h x wk(-1) and MET-h x wk(-1) of activity, and television watching was expressed as h x d(-1). Analysis of variance on ranks was used to compare activity variables obtained by self-administration and interview. Agreement was assessed by nonparametric intraclass correlation coefficients. RESULTS: A significant effect of the mode of administration was found only for past-year leisure physical activity with lower values reported in self-administered conditions compared with interview. However, a high level of concordance between the two modes of administration was observed for all variables as shown by the intraclass correlation coefficients: 0.90 for leisure physical activity (h x wk(-1)), 0.82 for occupational activity (h x wk(-1)), 0.83 for total (leisure and occupational combined) physical activity (h x wk(-1)), and 0.97 for television viewing (h x d(-1)). CONCLUSIONS: The agreement between the two modes of administration of the questionnaire suggests that the self-administered version of the MAQ is a valuable tool to assess past-year physical activity and inactivity in self-administered conditions. This instrument could be used in large-scale population studies investigating the relationships between physical activity and health outcomes.

Correlates of quantitative ultrasound in the Women's Healthy Lifestyle Project.

Quantitative ultrasound (QUS) assessment of bone is a strong predictor of hip fractures and is currently an FDA-approved tool to identify women at risk of osteoporosis. However, few studies have investigated the lifestyle and genetic correlates of QUS in women. This study investigated the cross-sectional associates of several lifestyle, demographic and genetic factors with calcaneal QUS parameters (broadband ultrasound attenuation (BUA) and speed of sound (SOS)) in 393 women aged 45-53 years. Leisure-time and historical physical activity, dietary calcium and protein, body composition, vitamin D receptor genotypes, menopause status, other health behaviors, calcaneal QUS parameters and bone mineral density (BMD) were assessed at a single clinic visit. Lean mass, recent physical activity and African-American race were the strongest correlates of SOS whereas dietary protein, calcium and recent physical activity were the strongest correlates of BUA. These predictors explained 13% and 6% of the variance in SOS and BUA, respectively. Smoking, alcohol intake, education, hormone replacement therapy, calcium and vitamin D supplements, historical physical activity and vitamin D receptor genotypes were not significantly associated with BUA or SOS. Lean body mass and premenopausal status were the strongest correlates of lumbar BMD whereas lean body mass, physical activity, African-American race and body mass index were significantly related to femoral neck BMD. Physical activity remained predictive of SOS after controlling for lumbar BMD. The spectrum and magnitude of risk factors for SOS and BUA, including lean body mass, physical activity, race, protein and calcium intake, parallel previously observed predictors of BMD.