With three weeks to go until Easter Sunday, half of the UK public have already bought and eaten at least one Easter-related chocolate treat and almost a quarter (23%) have already bought and eaten at least one full-sized Easter egg, the Royal Society for Public Health (RSPH) found.
More than three-quarters of the public (77%) think supermarkets are selling Easter confectionery too early, the survey suggests.
Some 57% of parents say their child has been tempted by Easter-themed treats displayed near checkouts.
And more than two-thirds of people (68%) surveyed think retailers use holidays or special occasions too much to advertise and sell unhealthy food, with 38% claiming that their diet is less healthy than normal when supermarkets push seasonal products.
Latest figures suggest that around 27% of UK adults are obese, the highest rate in Western Europe.
More than 20% of Year 6 pupils are obese and as many as 4.2% are now “severely obese”.
The average Easter egg contains almost three-quarters of an adult’s recommended daily calorie intake, the RSPH said.
RSPH chief executive Shirley Cramer said: “We recognise that special occasions such as Easter are a time for indulgence and treats. However, it is clear that many shops and supermarkets are pushing products way too early - it isn’t uncommon to find Easter eggs on sale in the first week of January.
“Our research suggests that the public find this mildly irritating and it is just putting unnecessary temptation out there, particularly for children.
“If supermarkets are serious about tackling the obesity epidemic, we would urge retailers to change their marketing strategies in the interest of the public’s health.”
Louise Meincke, head of policy at the World Cancer Research Fund, said: “Advertising and selling Easter eggs weeks, and sometimes even months, in advance of the holiday is just another tactic used by industry to encourage people to make unhealthy choices. This is unacceptable during the current global obesity crisis.
“We want the Government to lead the way by implementing policies that make our daily environments healthier. This would help parents give their children the best start in life by reducing their risk of cancer and other health conditions associated with obesity.”
Populus surveyed 2,000 UK adults between March 22 and 24.