To expand on the answer, the general gist is to create a database role and assign permissions to that role. In order to do that, you need some fancy dynamic SQL such as:
Set @Routines = Cursor Fast_Forward For
Select ROUTINE_SCHEMA + '.' + ROUTINE_NAME, ROUTINE_TYPE, DATA_TYPE
From INFORMATION_SCHEMA.ROUTINES
Where ROUTINE_NAME NOT LIKE 'dt_%'
Or ROUTINE_TYPE = 'FUNCTION'
Open @Routines
Fetch Next From @Routines Into @Procname, @RoutineType, @DataType
While @@Fetch_Status = 0
Begin
Set @Msg = 'Procname: ' + @Procname + ', Type: ' + @RoutineType + ', DataType: ' + Coalesce(@DataType,'')
Raiserror(@Msg, 10, 1) WITH NOWAIT
If @RoutineType = 'FUNCTION' And @DataType = 'TABLE'
Set @SQL = 'GRANT SELECT ON OBJECT::' + @Procname + ' TO StoredProcedureDataReader'
Else
Set @SQL = 'GRANT EXECUTE ON OBJECT::' + @Procname + ' TO StoredProcedureDataReader'
exec(@SQL)
Fetch Next From @Routines Into @Procname, @RoutineType, @DataType
End
Close @Routines
Deallocate @Routines
This code will grant EXECUTE to stored procedures and scalar functions and SELECT to user-defined functions that return a TABLE type.