Systemic lupus erythematosus (SLE) is an autoimmune disease characterized by an abnormal inflammation affecting multiple organs, blood formation processes and the central nervous system. The condition is still not well understood and hence more specific and effective treatment options are lacking. How diet and lifestyle may play a role in the disease’s onset and development is still disputed, yet some nutritional aspects appear to be associated with SLE. This systematic review gathered clinical and preclinical evidence from animal and human studies, investigating dietary and nutritional interventions that either proved helpful in the management of SLE or had adverse effects. The review considered the impact of reduced calorie intake and body weight. It discussed the value of lower protein intake, in the context of SLE-related kidney complications and polyunsaturated fats such as omega-3 and olive oil and their role in regulating inflammatory pathways. Furthermore, it stressed the importance of fibre in gut health and immune regulation in SLE. The study also included evidence from Vitamin A, B, C, D and E, with particular detail on Vitamin D and its relation to disease prevention, progression and its immune regulatory capacity. Towards the end is a brief table displaying the more limited finding on some minerals, before exploring the plant-derived compound group of polyphenols and finally Royal jelly. In short, the authors suggested that moving towards a balanced diet can address unfavourable nutritional shortages commonly observed in SLE patients. A diet that is low in calories and protein but plentiful in fibre, polyunsaturated fats, vitamin A, B, C, D, and E, minerals and polyphenol-containing foods. Evidently, the components of such a diet have favourable effects on regulating inflammation and immune function and thus overall disease activity. This review affirms the importance of nutritional adequacy for the management of SLE.