Twenty-four-hour dietary recalls can provide high-quality dietary intake data, but are considered expensive, as they rely on trained professionals for both their administration and coding. The objective of this study was to develop an automated, self-administered web-based 24-h recall (R24W) for a French-Canadian population. The development of R24W was inspired by the United States Department of Agriculture (USDA) Automated Multiple-Pass Method. Questions about the context of meals/snacks were included. Toppings, sauces and spices frequently added to each food/dish were suggested systematically. A list of frequently forgotten food was also suggested. An interactive summary allows the respondent to track the progress of the questionnaire and to modify or remove food as needed. The R24W prototype was pre-tested for usability and functionality in a convenience sample of 29 subjects between the ages of 23 and 65 years, who had to complete one recall, as well as a satisfaction questionnaire. R24W includes a list of 2865 food items, distributed into 16 categories and 98 subcategories. A total of 687 recipes were created for mixed dishes, including 336 ethnic recipes. Pictures of food items illustrate up to eight servings per food item. The pre-test demonstrated that R24W is easy to complete and to understand. This new dietary assessment tool is a simple and inexpensive tool that will facilitate diet assessment of individuals in large-scale studies, but validation studies are needed prior to the utilization of the R24W.

Objective: To determine whether vitamin D₃ supplementation improves insulin sensitivity, using the hyperinsulinemic-euglycemic clamp. Design: This single-centre, double-blind, placebo-controlled trial randomised 96 participants at high risk of diabetes or with newly diagnosed type 2 diabetes to vitamin D₃ 5000 IU daily or placebo for 6 months. Methods: We assessed at baseline and 6 months: (1) primary aim: peripheral insulin sensitivity (M-value using a 2-h hyperinsulinemic-euglycemic clamp); (2) secondary aims: other insulin sensitivity (HOMA2%S, Matsuda) and insulin secretion (insulinogenic index, C-peptide area under the curve, HOMA2-B) indices using a 2-h oral glucose tolerance test (OGTT); β-cell function (disposition index: M-value × insulinogenic index); fasting and 2-h glucose post OGTT; HbA_1c; anthropometry. Results: Baseline characteristics were similar between groups (% or mean ± s.d.): women 38.5%; age 58.7 ± 9.4 years; BMI 32.2 ± 4.1 kg/m²; prediabetes 35.8%; diabetes 20.0%; 25-hydroxyvitamin D (25(OH)D) 51.1 ± 14.2 nmol/L. At 6 months, mean 25(OH)D reached 127.6 ± 26.3 nmol/L and 51.8 ± 16.5 nmol/L in the treatment and placebo groups, respectively (P < 0.001). A beneficial effect of vitamin D₃ compared with placebo was observed on M-value (mean change (95% CI): 0.92 (0.24–1.59) vs −0.03 (−0.73 to 0.67); P = 0.009) and disposition index (mean change (95% CI): 267.0 (−343.4 to 877.4) vs −55.5 (−696.3 to 585.3); P = 0.039) after 6 months. No effect was seen on other outcomes. Conclusions: In individuals at high risk of diabetes or with newly diagnosed type 2 diabetes, vitamin D supplementation for 6 months significantly increased peripheral insulin sensitivity and β-cell function, suggesting that it may slow metabolic deterioration in this population.

Assessment of food intake is a cornerstone of nutritional research. However, the use of minimally validated dietary assessment methods is common and can generate misleading results. Thus, there is a need for valid, precise and cost-effective dietary assessment tools to be used in large cohort studies. The objective is to validate a newly developed automated self-administered web-based 24-h dietary recall (R24W), within a population of adults taking part in fully controlled feeding studies. Sixty two adults completed the R24W twice while being fed by our research team. Actual intakes were precisely known, thereby allowing the analysis of the proportion of adequately self-reported items. Association between offered and reported portion sizes was assessed with correlation coefficients and agreement with the kappa score while systematics biases were illustrated with Bland-Altman Plot. Participants received an average of 16 food items per testing day. They reported 89.3% of the items they received. The more frequently omitted food categories were vegetables included in recipes (40.0%) as well as side vegetables (20.0%) and represented less than 5% of the actual daily energy intake. Offered and self-reported portion sizes were significantly correlated (r = 0.80 P < 0.001) and demonstrated a strong agreement as assessed by the kappa score of 0.62. Reported portion sizes for individual food items were on average 3.2 g over the offered portion sizes. Portions of 100 g and above were on average underestimated by 2.4% (r = 0.68 P < 0.01; kappa score = 0.50) while small portions (less than 100 g) were overestimated by 17.1% (r = 0.46 P < 0.01; kappa score = 0.43). A nonsignificant underestimation (−13.9 kcal ± 646.3 kcal; P = 0.83) of energy intake was noted. R24W performed well as participants were able to report the great majority of items they ate and selected portion size strongly related to the one they received. This suggests that food items are easily to find within the R24W and images of portion sizes used in this dietary assessment tool are adequate and can provide valid food intake evaluation.