4. Discussion
caloric deficit, weight loss, TNF-α
RHEUMATOID ARTHRITIS, DISEASE, DISEASES
This study compared the effects of nutritional counselling on fasting and a whole-food plant-based diet to those of a DGE diet on the actual dietary behavior of patients with rheumatoid arthritis. Moreover, their respective effects on the nutrient supply were investigated.Our cluster analysis across the dietary patterns did not reveal clusters that could clearly be associated with the two intervention groups. This does not necessarily indicate the inefficacy of the interventions or the dietary counselling. First, our study interventions improved RA disease activity to similar degrees in both groups [The intricate influences of nutrition on health and disease are challenging to study. For a better understanding, they may be broken down into the direct and indirect cause–effect relationships of dietary components: turmeric, for instance, directly inhibits the production of proinflammatory cytokines such as TNF-α in several in vitro and in vivo studies [We did not study the further beneficial effects of fasting in this RCT, such as DNA repair, autophagy and enhanced immune function [Regarding nutrient supply, both groups maintained their daily intake of carbohydrates, sugars, fiber and protein over the course of the study.However, the fasting and PBD group indicated a reduced energy intake by approximately 100 kcal during the study period compared with the baseline. Although this trend was not statistically significant, it may still have produced a clinically relevant effect over 3 months. One possible explanation for the weight loss of approximately 5% in the fasting and PBD groups is the relative caloric deficit [With respect to macronutrients, the fasting and PBD group consumed significantly less total saturated fat than the DGE group, which favors a protective cardiovascular profile [Though not significant, we observed a trend towards higher intake of unsaturated fatty acids in the fasting and PBD group. An enhanced intake of such fats has been associated with a beneficial response in terms of RA disease activity [The average daily intake of protein in the DGE group exceeded that of the fasting and PBD group and even the daily recommended intake. Epidemiological studies underscore that a high intake of animal protein, particularly red meat, may be related to the promotion of age-related diseases and mortality. This association seems to be abolished or attenuated when proteins are plant-derived [As for micronutrients, the DGE group had a greater intake of vitamin A, vitamin B12, vitamin D, riboflavin and calcium (each This study has several strengths. The parallel study design minimized unanticipated variation during the study period. With the COVID-19 pandemic, we changed personal coaching to remote consultations. Both groups were equally exposed to the matched intervention modality. In addition, the presented data are derived from a prospective intervention rather than an observational study, which renders them more informative.The present study also has several limitations. First, the food records were self-recorded by the study participants, which required intensive participant involvement. As a result, the quality of these data might vary interindividually and represents a source of information bias. Specifically, dietary intake was adjusted for the physical activity level of the participant, but no other method was applied for the plausibility verification of this self-reported item. The parallel study design is a strength; on the other hand, this study design requires a larger sample size than, for example, a crossover design to achieve similar statistical power [