Sell-side analysts have highlighted disappointing second-half results in their wrap-ups of the big banks' 2010/11 financial reports, questioning where the growth will come from in the year ahead.In reports to clients, they have noted that outlook statements have gone from being confident that demand for lending would rebound to being hopeful, at best."The banks delivered zero growth in pre-provision profit during the September half," said UBS analyst Jonathon Mott, in a note issued on Thursday."We believe that the banks are structurally challenged, with consumer and business preference for deleveraging likely to prevent a material recovery in credit growth."Much recent profit growth has been driven by reductions in bad debt charges, but analysts questioned whether much more could be gained from that source in the year ahead.If there are gains to be made, they will come from cost reductions and business efficiency programs.  During investor briefings over the past couple of weeks, analysts asked whether banks should be setting cost management targets. There were complaints from analysts who felt efficiency programs were not delivering clear benefits.Citi's note on the Westpac result said: "Shareholders remain unclear on the size and scope of slated productivity initiatives, leaving us less certain that Westpac will positively differentiate itself on cost growth."Citi was even more sceptical of the progress of National Australia Bank's NextGen IT platform and took a shot at the bank's "bare disclosure".Macquarie Research questioned whether ANZ had a sustainable growth strategy in Asia. In a note headed "Small fish in a crowded pond", it said: "Margins and returns from ANZ's Asian business continue to be under pressure."Management suggests that competition may actually decline as the Europeans are forced to sell assets and leave Asia. While [this is] possible, we believe the competition is likely to continue to be strong."Macquarie is also sceptical of the view put forward by bank CEOs over the past couple of weeks that their under-performing institutional businesses will pick up with a recover in trading activity. It said that taking positions on interest rate and currency movements would be a tough game for some time to come.