Polling by YouGov on behalf of Citizens Advice Scotland (CAS) found 36 per cent of people find their bills unaffordable.
Some 54 per cent of these said they have had to reduce household expenditure at least once to afford bills.
Asked to identify what spending was cut back, 56 per cent of these people said groceries.
Based on the latest population estimate for over 18s in Scotland, CAS said this would work out at around 483,255 people.
The charity is releasing the figures as part of its "Big Energy Saving Winter" campaign, which is encouraging people to seek advice to manage soaring energy bills.
This week it was revealed inflation has hit a ten-year high at 5.1 per cent.
Derek Mitchell, chief executive of CAS, said: “This shocking analysis lays out the reality of the cost of living crisis in Scotland today.
"An estimated half a million people are cutting back on their weekly food shop to afford soaring energy bills, and this should have alarm bells ringing.
“We’ve seen a perfect storm this winter. Rising energy bills, increasing inflation and cuts to people’s incomes from the £20 reduction in Universal Credit.
“People will be facing challenges but the CAB network’s message to them is you are not alone.
"You don’t need to feel powerless about rising energy bills, we’re here to help with free, impartial and confidential advice.
“Last year we unlocked £147 million in gains for people, and helped over 171,000 people. We’ve been helping people for over 80 years and we’re here to help now.”
YouGov polled 1,011 adults between November 11 and 15.
Scottish Greens energy and climate spokesman Mark Ruskell said: “This timely analysis from Citizen’s Advice Scotland reveals the devastating impact of Boris Johnson’s decision to slash Universal Credit payments by £20 per week.
"Cuts to support, combined with soaring inflation, means the Tories are driving more and more households into poverty. And there’s a national insurance hike still to bite.”
A Scottish Government spokesman said: “Citizens Advice Scotland’s Big Energy Saving Winter campaign rightly highlights that it is imperative that those worried about or struggling with their energy bills access the information and support they need to reduce their energy bills.
“Everyone needs a safe, warm place to call home and we know that the energy price rises will be causing many people to worry about the cost of their fuel bills.
"Our foremost concern is for households who are affected by these price rises - particularly those who are in or at risk of fuel poverty - and we are making £10 million of funding available through our Fuel Insecurity Fund to help people struggling with their heating costs this winter.
“We have also increased funding this year for our Warmer Homes Scotland scheme, which can help households in fuel poverty make their homes warmer and more affordable to heat.
"We would urge anyone struggling to heat their homes to call the Home Energy Scotland service for advice and support.”