The work carried out by Aviva demonstrated that, despite growing incomes, over 55s have had to spend more on items such as food, energy and housing.
Typical spending by over 55s has risen by 9% in the past year –with extra outgoings adding up to £116 a month or £1,392 a year.
Aviva said this is about the same as a month worth of bills.
Although rising expenditure has overshadowed it, Aviva's Real Retirement research showed that over-55s' monthly income reached £1,545 in January 2014 – the highest figure in the four years since Aviva began tracking this data.
Incomes have typically risen by 7% in the last year from £1,444 in December 2012. This made a difference of £101 each month or £1,212 each year to the typical over-55.
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The trend looks to have been fuelled by a jump in those aged 55-64 who receive wages and other earnings - 62% compared to 55% in December 2012.
More over-55s have also been drawing income from employer pensions.
Some 9% of over-55s received less than £500 income each month and 17% got less than £750 - the lowest since February 2010.
Clive Bolton, Aviva's managing director of at retirement, said: "Planning for retirement is challenging enough for many people without the added pressure of larger bills for essential costs and the threat of further increases in 2014.
"While over-55s typically have more income at their disposal than they did a year ago, many are finding they have less freedom to decide what to put their extra money towards, as essential costs rear their heads and push to the front of the queue."