**5. Conclusions**

Although the effect on HEI-NVS was small in the intervention group, this study demonstrated that a fully automated web-based weight loss intervention with focus on dietary energy density improved compliance with the national dietary recommendation. This result is relevant for all people aiming to reduce their body weight and eat healthier at the same time, but do not have access to personal care. Furthermore, the change in HEI-NVS showed an inverse correlation with the change in dietary energy density. Improvements in HEI-NVS were not associated with improvements in anthropometric and cardiometabolic variables. Interestingly, improvements in HEI-NVS were associated with only weak unfavorable effects on fat-free mass and fasting blood glucose. One might speculate that a diet quality index addressing other components, such as whole grains or salt, would have found more beneficial relationships. In the future, more intervention studies should address the association of diet quality and cardiovascular risk factors to examine the short-term effects of diet quality. This would provide a better understanding of the health effects of diet quality or related indices.

**Supplementary Materials:** The following supporting information can be downloaded at: https: //www.mdpi.com/article/10.3390/nu15010007/s1, Table S1: Components and scoring standards of the HEI-NVS; Table S2: Descriptive statistics of variables used for correlation independent of study group. File S1: CONSORT-EHEALTH Checklist.

**Author Contributions:** Conceptualization, J.K., J.B., R.W., M.S., U.A.F., C.A., I.T., P.M., E.F.-G., R.F., A.G. and D.K.; methodology, J.K., J.B. and D.K.; formal analysis, J.K.; investigation, J.K., J.B. and P.H.; resources, J.B. and D.K.; data curation, J.K., J.B. and P.H.; writing—original draft preparation, J.K.; writing—review and editing, J.K., J.B., P.H., R.W., M.S., U.A.F., C.A., I.T., P.M., E.F.-G., R.F., A.G. and D.K.; visualization, J.K.; project administration, J.K., J.B. and D.K.; funding acquisition, D.K. All authors have read and agreed to the published version of the manuscript.

**Funding:** This research was funded by the Techniker Krankenkasse (German Health Insurance Company). The APC was funded by the Open Access Publication Fund of the University of Freiburg.

**Institutional Review Board Statement:** The study was conducted in accordance with the Declaration of Helsinki, and approved by the ethics commission of Albert-Ludwigs-University, Medical Center, Freiburg (vote no. 237/19) on 25 July 2019. The study was registered in the German Clinical Trials Register before the commencement of the intervention (DRKS00020249, https://www.drks.de), which is approved by the World Health Organization. Due to the results of two clinical pilot studies (vote no. 409/18, DRKS00016512), minor changes were made to the study protocol and positively assessed by the ethics commission (date of approval: 22 October 2019, protocol version: amendment 01).

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

**Data Availability Statement:** The data of this study are the property of the Department of Sport and Sport Science of the University of Freiburg. The results of the clinical trials are presented to the scientific community and the trial sponsor as aggregated research data. Data on individual subjects cannot be reconstructed. No further data of the clinical trials are released to the scientific community or third parties.

**Acknowledgments:** We would like to thank all study participants as well as the study staff. Furthermore, we would like to thank Irina Kopman and her team at Vilua Healthcare GmbH for the extensive IT support. Finally, we would like to thank the Techniker Krankenkasse, represented by Nicole Knaack, Kerstin Hofreuter-Gätgens and Dagmar Köppel, for funding this study.

**Conflicts of Interest:** J.K., J.B., P.H. and D.K. report funding by the Techniker Krankenkasse for clinical trial design, implementation, and scientific evaluation. R.W., R.F., M.S., I.T., E.F., C.A., U.A.F. and P.M. report funding by the Techniker Krankenkasse for the design, implementation, and scientific evaluation of the online trials. A.G. declares no conflict of interest. The funders had no role in the design of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript; or in the decision to publish the results.
