Dr Aifric O'Sullivan, an Assistant Professor at UCD School of Agriculture and Food Science, Principal Investigator at UCD Institute of Food and Health and Deputy Vice Principal (International) at UCD, share her tips on avoiding food waste at home.

Food waste at home refers to food that is not eaten and so is thrown out. This can happen when food goes past its "use by date" or when "leftovers" are thrown away. There are other ways that food is wasted during production and food processing.

Overall, it is estimated that one-third of the world's food is wasted every year. If you think about what we described earlier in relation to the GHGEs that are generated when food is produced, processed, and transported then you can see how this food waste will impact the environment.

Not only that, but wasted food goes to landfills or incineration and so has a further impact on the environment. In Ireland, it is estimated that we spend between €400 and €1,000 a year on food that ends up in the bin. There are different ways that we waste food at home:

Avoidable food waste such as plate scrapings, leftovers and gone-off fruit and vegetables. Avoidable food waste accounts for about 60% of all food wasted in our homes.

Potentially avoidable food waste includes things like bread crusts and potato skins. This is food waste which could be eaten or used in another way. Potentially avoidable food waste accounts for 20% of all food waste.

Unavoidable food waste such as banana skins, orange peel and chicken bones. Only 20% of our food waste is unavoidable. Use your food waste bin for this type of food waste.

Tips to reduce food waste: meal planning and shopping

1) Plan your meals

Plan meals around your weekly activities

Plan meals based on foods that need to be used up

Plan a second meal around leftovers

Use fresh fruits and vegetables first then frozen/canned foods later

2) Shop smart

Check your fridge, freezer and cupboards before shopping to see what you have

Make a list before shopping

Only buy what you need

Don’t be tempted by goods on promotion that you don’t need

Tips to reduce food waste: storing your food

1) Make sure your fridge temperature is set to below 5 degrees

2) Store leftovers in clear containers- this will make it easier to keep track of what you

3) Move older foods to the front of the fridge and put new foods in the back- this will encourage the use of older items before they go bad

4) Don't keep milk, cheese and yoghurt in the fridge door- this is where the temperature is warmest so keep these on the fridge shelves to keep cooler and fresher for longer

5) Don’t slice food until you’re ready to use it- chopped fruit, cheese and veg will spoil faster

6) Freeze your bread- bread is one of our most wasted foods. Why not freeze and have toasted if you don’t think you’ll eat it all before it goes off?

Tips to reduce food waste: knowing what date labels mean

BEST BEFORE: 'Best before' refers to quality: your food will be at its best before the date given. After this date, it might not be at its best, but it will still be safe to eat. Use your senses to make a judgement.

USE BY: 'Use by’ refers to safety: you must not eat food past the ‘use by’ date. You cannot always smell the bacteria that causes food to spoil, so after the ‘use by’ date, the food may appear perfectly fine to eat, but could still lead to food poisoning. Therefore, you should NOT eat food after the ‘use by’ date - even if it looks and smells OK.

DISPLAY UNTIL / SELL BY: These dates are for the retailers – not us at home. You don’t need to worry about these.

Tips to reduce food waste: portion control

1) Shopping: Only buy what you need

2) Cooking: Cook what you need, or plan how you will use leftovers

3) Serving: Only plate the amount of food you intend to eat and enough for 1 meal.

4) Storage: Keep leftovers in a clear container and where you can see them in the fridge.

Tips to reduce food waste: cooking

1) Using up vegetables: Soups, curries, casseroles and stir-fries are a great way to use up vegetables such as carrots, broccoli, spinach and tomatoes.

2) Using up meats: Leftover meat from a roast dinner such as chicken, turkey, pork or beef are great sandwich fillers for lunch the next day

3) Using up fruits: Ripe avocados and bananas make great guacamole or banana bread.

Watch What Planet Are You On? on RTÉ One from 11-13 October.