The purpose of the study was to assess the effects of anthocyanin-rich Queen Garnet plum juice (QGPJ) on body weight and expression of leptin and adiponectin. Queen Garnet plum is a Japanese plum (Prunus salicina) cultivar developed through a Queensland Government breeding program with very high levels of anthocyanins (272 mg/100 g). Twenty healthy volunteers were supplemented with 200 ml/day of QGPJ and placebo drink for 4 weeks. Supplementation with QGPJ significantly reduces body weight and BMI (p < 0.05) with the average decrease of 0.6 kg in body weight and 0.2 units in BMI over the period of 4 weeks. Furthermore, consumption of QGPJ significantly increases adiponectin blood levels (p < 0.05) (average increase of 3.83 µg/mL) and decreases leptin blood levels (average decrease of 1.31 ng/mL). QGPJ may have potential to be used as a functional food for preventing obesity and obesity related disorders.