The cost of household energy has risen more than five times faster than household income since 2004, according to a study.
And the average household's annual energy bill of £1,252 now accounts for 11% of a couple's basic state pension of £11,175 a year, the study by price comparison website uSwitch.com found.
The cost of energy is now the top household worry for Britons (90%), ahead of the rising cost of food (77%) and mortgage payments (42%).
Almost a third of consumers (32%) say that household energy is unaffordable in the UK, the poll found.
While the average UK household income has increased by 20% from £32,812 in 2004 to £39,468 today, the average energy bill has risen by 140%, according to uSwitch figures.
Households were spending an average of £522 a year for their energy in 2004, but now pay £1,252 a year - 3.2% of income or double the 1.6% of eight years ago. Britons now have an average of £297 of disposable income left each month after all essential household bills are paid.
The study found 83% of people believe that rising energy bills have had an impact on their disposable income, with 17% of these reporting that they no longer have any disposable income as a result and 27% saying energy bills have reduced their disposable income dramatically.
Director of consumer policy at uSwitch.com Ann Robinson said: "This is the cold reality facing households today; in less than 10 years our energy bills have rocketed by 140%. The break-neck speed at which energy prices have sprinted upwards has caught many people unawares. Consumers are still playing catch-up.
"Energy now accounts for a significant slice of household income which is why the numbers rationing their energy use have risen so steeply in recent years. But going cold or without is a short-term and potentially harmful fix and not a long-term solution.
"The fact is that consumers can control how much they spend on energy by making their homes more energy-efficient and paying less for the energy they do use by moving to a competitively-priced energy plan."