*4.12. Statistical Analysis*

The sample size was determined based on insulin reduction after a single acute intake of 2 capsules of 250 mg of a polyphenol-enriched brown seaweed extract from data published by Paradis et al. [19] with a statistical power of 80%, yielding a sample size of 27 for each group. Statistical analyses were performed using the statistical analysis software SPSS (version 22, 2007, IBM SPSS Statistics), except for data from OGTT, which were analyzed using SAS 9.4 (SAS Institute, Cary, NC, USA. Results are presented as means ± standard deviation. The primary analysis was to compare plasma glucose, insulin, and C-peptide obtained with OGTT before and after the intervention between the placebo and treatment. For that purpose, a mixed model for repeated-measures ANOVA with three factors (treatment, OGTT time points, post-pre phase) was performed. Incremental area under the curve (IAUC) for glucose, insulin, and C-peptide during the 2 h-OGTT was calculated from the trapezoidal rule and fasting baseline values. A repeated-measures ANOVA test with two factors (treatment, post-pre phase) was performed to compare changes over time (post-pre) between groups for the other parameters. Prior to performing repeated-measures ANOVA, normality was checked using a Shapiro–Wilk test, and distribution was normalized using logarithmic transformation when needed. Student's *t*-test (when data were normally distributed) and Mann–Whitney U test (when data were abnormally distributed) were performed to compare means at pre-intervention between groups, and F2-isoprostane changes from baseline between and within groups. Considering the small size of the experimental groups and the multiplicity of analysis, a Bonferroni correction was performed for the anthropometric (*p* ≤ 0.01), blood pressure and heart rate (*p* ≤ 0.02), glycemic (*p* ≤ 0.005), lipid (*p* ≤ 0.01), hepatic (*p* ≤ 0.02), inflammatory and oxidative stress (*p* ≤ 0.02), and gut integrity (*p* ≤ 0.03) markers. To detect associations between variables, Pearson correlation coefficients were calculated using the Pearson correlation (CORR) procedure. Differences were considered significant at *p* ≤ 0.05 (two-tailed) level.

**Supplementary Materials:** The following are available online at https://www.mdpi.com/article/ 10.3390/md20030174/s1, Table S1: Subjects' characteristics; Table S2: Nutritional intakes over time within and between groups; Figure S1: Flow chart.

**Author Contributions:** Conceptualization and design, J.M., S.J.W. and H.J.; data acquisition, analysis, interpretation, M.V., J.M., V.G., N.L., J.-F.B., S.J.W. and H.J.; critically revising the manuscript, M.V., J.M., V.G., N.L., J.-F.B., S.J.W. and H.J. All authors have read and agreed to the published version of the manuscript.

**Funding:** This research was funded by a grant from the Ministry of Agriculture, Fisheries, and Food of Québec (MAPAQ) and innoVactiv. InnoVactiv also provided the placebo and brown seaweed supplements. Marlène Vodouhè was supported by MITACS Acceleration Scholarship.

**Institutional Review Board Statement:** The study was in accordance with the Declaration of Helsinki and approved by the Health-Science Research Ethics Committee of Université Laval (protocol code 2016-227 and date of approval 11 January 2016).

**Informed Consent Statement:** Informed consent was obtained from all subjects involved in the study.

**Data Availability Statement:** Data available on request due to ethical restrictions.

**Acknowledgments:** The authors sincerely acknowledge volunteers who agreed to participate in this project. We are also grateful to Steeve Larouche and Danielle Aubin, nurses at the Institute of Nutrition and Functional Foods (INAF), Laval University, for performing blood collection and OGTTs, Amélie Charest and Iris Gigleux from INAF for their help in assessing body composition and Karine Greffard for F2-isoprostane assessment. We would like to also thank Hélène Crépeau, Anne-Sophie Julien, and Pierre Gagnon from Laval University for their help in statistical analyses.

**Conflicts of Interest:** Authors declare no potential conflict of interest.
