the intervention of l-theanine on behavior changes induced by high protein diet in ratssong yuxin, zhang jiao, he lin, li lanlan, chen meiyan, zhang yangling, qu qingyun, xiao wenjun*（key lab of tea science of ministry of education, hunan agricultural university, hunan agricultural university, national research center of engineering technology for utilization of botanical functional ingredients, changsha, 410128, china）