Rising food prices are causing stress for four in 10 consumers, while a third say they are struggling to feed themselves or their family.
Almost eight in 10 shoppers (78%) are concerned about the increasing cost of food, with almost half (45%) spending a larger proportion of their available income at the supermarket compared to a year ago, the survey for Which? found.
Food prices have risen over and above general inflation by 12.6% over the past six years, according to the Office of National Statistics, while incomes have stagnated.
The poll found 60% are worried about how they will manage their future spending on groceries if prices continue to rise, and 41% say the cost of food is a source of stress.
Almost a third (29%) say they struggle to feed themselves or their family because of the cost.
A separate survey by the consumer watchdog found one million more households are feeling financial pressure compared to a year ago, leaving 9.5 million households struggling to cope with the cost of living.
It found 40% are likely to cut back spending on food in the next few months.
Which? executive director Richard Lloyd said: "While people seem to have accepted their grocery bill going up, stagnating incomes and rocketing food prices are causing stress and worry and leaving people wondering how they are going to cope.
"Supermarkets need to make it much easier for consumers to spot the best deal by ensuring pricing is simple and making special offers genuinely good value for money.
"Politicians need to put consumers at the heart of their economic policies to tackle the rising cost of living and to support growth and prosperity."