When applying for a mortgage, the lender or broker typically asks several questions regarding your income and expenditure. One question often asked is how much money you typically spend per month on food / drink / groceries. Another question often asked is how much you spend on leisure / clothes / holidays / other personal items.
However, these kind of expenditures are not verifiable through official documentation, such as a payslip. Furthermore, it is very difficult to predict the amount you spend, as this often changes with lifestyle / time of year / working hours. Finally, mortgage applicants could simply lie and give a lower estimate than the truth, to make themselves appear less of a risk to the lender.
So why are these questions asked at all? Instead, why do lenders not simply ask for bank statements and make the estimate themselves?