Tesco is dropping some food promotions after finding that two-thirds of bagged salads are thrown out.
The supermarket giant has revealed food waste figures for its operations for the first time.
The figures reveal that 68% of salads sold in bags are thrown out, with 35% in the home.
As a result of the findings, it is to end multi-buys on large bags of salad.
It is developing mix-and-match promotions for smaller bags in an attempt to help customers reduce the amount they are wasting.
Tesco is also removing "display until" dates from fresh fruit and vegetables.
It will use smaller cases in stores and rearranging 600 in-store bakeries to reduce the amount of bread on display.
The retailer found that 40% of apples are wasted, as are just under half of bakery items.
A quarter of grapes are wasted between the vine and the fruit bowl and a fifth of all bananas are unused, with customers throwing one in ten in the bin.
Tesco said it was involved in trials with apple growers to reduce pests and disease.
The supermarket will provide simple tips to customers about storing the fruit after finding that more than a quarter of wastage happens at home.
It will also share tips with customers about how to use leftover bread.
The company is working with grape and banana suppliers to improve delivery times and conditions.
The supermarket tracked 25 best-selling products and combined information with data from the Waste and Resources Action Programme (Wrap) to give an overall food waste "footprint" for each item.
The data shows that in the first six months of this year, 28,500 tonnes of food waste were generated in Tesco's stores and distribution centres.
The last figures published by Wrap in 2011 estimate that 15 million tonnes of food waste is generated each year in the UK.
Tesco commercial director of group food Matt Simister said: "We've all got a responsibility to tackle food waste and there is no quick-fix single solution."
He said: "Little changes can make a big difference, like storing fruit and vegetables in the right way."
"We're playing our part too and making changes to our processes and in store.
"Ending multi-buy promotions on large packs of bagged salads is one way we can help, but this is just the start and we'll be reviewing what else we can do. We're working with our suppliers to try to cut waste at all stages of the journey from farm to fork."
Wrap director Richard Swannell said: "We welcome Tesco's approach to tackling food waste across their whole supply chain, and by identifying the hot spots they can tackle these areas effectively.
"Food waste is a global issue and collaborative action is essential if we are to successfully reduce food waste and reap the financial and environmental benefits of doing so."