Compounds are provided which have the structure ##STR00001## wherein Q is C or N, X.sub.1 is C or N, and R.sup.1, R.sup.2, R.sup.2a, R.sup.2b, R.sup.2c, R.sup.3, Y, A, m, n, X.sub.2, X.sub.3 and X.sub.4 are as defined herein, which compounds are useful as antidiabetic, hypolipidemic, and antiobesity agents.