Basic, clinical, and epidemiologic research on carbohydrate-restricted dietary patterns continues to grow, evaluating the impact of this way of eating on weight loss, obesity-associated comorbidities, and development of any adverse effects. Randomized, controlled, dietary weight loss trials conducted in adults in the past 2 years reinforce previous findings that carbohydrate-restricted diets (CRDs) promote weight loss while increasing serum high-density lipoprotein cholesterol, lowering serum triglycerides, and improving glucose homeostasis. Studies showing that reduction of dietary carbohydrate leads to reduced postprandial serum glucose and insulin levels have spurred further research on CRDs in patients with type 2 diabetes. Emerging interest into the effect of diet on endothelial function has spawned studies that are harnessing new technologies, such as flow-mediated vascular dilation, to gain insight into the impact of diet on long-term cardiovascular disease outcomes. Studies on the effect of a CRD on appetite, health-related quality of life, bone density and turnover, acid-base metabolism, and potassium equilibrium help clinicians better weigh the perceived risks of the diet with the recognized benefits. This review synthesizes important clinical and physiologic studies on CRDs published between January 2007 and May 2009.