Effect of low-fat diet interventions versus other diet interventions on long-term weight change in adults: a systematic review and meta-analysis - The Lancet Diabetes & Endocrinology

These findings suggest that the long-term effect of low-fat diet intervention on bodyweight depends on the intensity of the intervention in the comparison group. When compared with dietary interventions of similar intensity, evidence from RCTs does not support low-fat diets over other dietary interventions for long-term weight loss.