“…Then another 26 articles were excluded for the different reasons indicated in Figure 1 . As shown in Table 1 , three were conducted in China ( 18 , 29 , 45 ), five in the USA ( 14 , 34 , 42 ), four in Poland ( 19 , 21 , 31 ), nine in Turkey ( 11 , 13 , 20 , 32 , 35 , 38 , 44 , 46 ), five in Spain ( 12 , 22 , 37 ), one in Australia ( 23 ), three in India ( 24 , 40 ), three in Greece ( 26 , 30 ), three in Italy ( 33 , 41 ), one in Brazil ( 36 ), two in Belgium ( 43 ), one in Egypt ( 15 ). With regard to ethnicity, 33 studies were performed with Caucasians ( 11 – 14 , 19 – 23 , 26 , 30 – 35 , 37 , 38 , 41 – 44 , 46 ), 11 with Asians ( 18 – 25 , 29 , 39 , 40 , 45 ), and one with Latinos ( 36 ) of the 45 studies, 13 reported leptin levels in plasma ( 12 , 14 , 19 , 22 , 30 , 33 , 42 , 46 ), and 32 ( 11 , 13 , 15 , 20 , 21 <...>…”