Goji berries have long been used to promote vitality, energy, and stamina. Research also suggests that goji berries may help improve metabolism that can help you on your journey to weight loss. A 2011 study published in in the ‘Journal of the American College of Nutrition’ found that people who had goji berry–based juice boosted their metabolic rate after meals by as much as 10%. In addition, those who had 120ml of goji berry juice for 14 days had reduced waist circumference.