OBJECTIVE: Assumptions have linked orange juice (OJ) consumption with weight gain and adverse effects on health due to its sugar content; however, epidemiologic studies have not shown increased risk for overweight or obesity with the consumption of 100% OJ. The aim of this study was to verify whether the combination of a reduced-calorie diet (RCD) and 100% OJ contribute to weight loss, promote changes in glucose and lipid metabolism, and improve diet quality in obese individuals. METHODS: A randomized controlled trial with 78 obese patients (age 36 ± 1 y, body mass index [BMI] 33 ± 3 kg/m2) were enrolled in two groups: Individuals in the OJ group submitted to an RCD that included OJ (500 mL/d), and individuals in the control group submitted to an RCD without OJ. Body composition, biochemical biomarkers, and dietary intake were analyzed over a 12-wk period. RESULTS: Both treatments had similar outcomes regarding body weight (-6.5 kg; P = 0.363), BMI (-2.5 kg/m2; P = 0.34), lean mass (-1 kg; P = 0.29), fat mass (-5 kg; P = 0.58), body fat (-3%; P = 0.15), and waist-to-hip ratio (-0.1; P = 0.79). Insulin levels in the OJ group decreased by 18% (P = 0.05), homeostasis model assessment-insulin resistance by 33% (P = 0.04), total cholesterol by 24% (P = 0.004), low-density lipoprotein cholesterol by 24% (P ≤ 0.001), and high-sensitivity C-reactive protein levels by 33% (P = 0.001) compared with the control group. Consumption of energy and nutrients was similar between the two groups, but vitamin C and folate increased by 62% (P ≤ 0.015) and 39% (P = 0.033), respectively, after OJ intervention. CONCLUSION: When consumed concomitantly with an RCD, OJ does not inhibit weight loss; ameliorate the insulin sensitivity, lipid profile, or inflammatory status, or contribute nutritionally to the quality of the diet.