adult controlled study male female 449 human 402 Male 387 Female 333 priority journal 325 Humans 309 article 308 Adult 231 Article 199 nonhuman 173 Middle Aged 168 Animals 141 aged 139 major clinical study 131 animal 122 clinical article 121 physiology 117 animal experiment 103 Aged 97 metabolism 85 animal tissue 75 middle aged 72 Young Adult 71 Adolescent 68 adolescent 68 human experiment 66 animal cell 64