Diet and lifestyle may influence existing rheumatic disease activity and the risk of developing related diseases in the future, and several studies published in 2015 have deepened our understanding of this understanding. A Japanese study found that smoking may reduce remission rates in men with rheumatoid arthritis (RA), although the effect was smaller in women. Along with the extensive research work previously conducted that has confirmed the association of smoking with sudden onset RA, treatment remission rates, and a variety of other health-related factors, these findings continue to provide impetus for smoking cessation efforts in patients with rheumatic diseases. Sparks and colleagues found that weight loss through bariatric surgery and other methods resulted in improved disease activity and systemic inflammatory response in patients with RA. In contrast, Baker and colleagues studied a cohort of RA patients derived from the VA database and found that weight loss in RA patients was a predictor of mortality. These findings are somewhat difficult to agree upon, but they may essentially examine the association between weight loss and RA from different perspectives; perhaps, intentional weight loss is beneficial, whereas unintentional weight loss predicts paradoxical, potentially lethal lesions. These issues have yet to be evaluated in research. However, weight loss should remain an important part of rheumatic disease management, given its recognized overall benefits for a variety of health problems, including reduced risk of cardiovascular disease, abnormal glucose metabolism, knee osteoarthritis, and mechanical joint pain. As for other specific dietary and lifestyle changes that may affect rheumatic diseases, Hu and colleagues analyzed data from the Nurses’ Health Study and found that the Mediterranean diet may not reduce the risk of developing RA in the future. In addition, vitamin D supplementation may not alter interferon markers in patients with lupus. A cross-sectional study by Katz and colleagues found that fatigue in patients with RA is likely to be multifactorial, including poor sleep quality, mood abnormalities, and obesity. Future studies should identify effective ways to address these issues.