Martin Lewis has warned people who have ditched ovens for microwaves and air fryers in order to save money to be mindful they aren’t using more energy as a result.

Air fryers have become hugely popular in recent years, and are the must-have kitchen item for many.

Soaring energy bills have accelerated the switchover for many people, with air fryers promising to use less energy than cooking in an oven.

However, Martin Lewis has called for people to be careful when swapping an oven for an air fryer or microwave to save money, with the air fryer costing more in some instances.

Isle of Wight County Press:

Speaking on his podcast, the Money Saving Expert said: “The problem with the equation for heating equipment is an oven is going to be about 2000W.

“A microwave I believe gives you consistent heat whereas an oven is warming up to full temperature and then topping it up so it isn’t running at full power the whole time.

“If you’re doing a jacket potato for 10 minutes in the microwave it is going to be cheaper than doing a single jacket potato in an oven for an hour and a half.

“However, if you were doing a full roast dinner and you were cooking many of them, that is where its probably cheaper than putting five or six jacket potatoes in a microwave because each additional object you put in a microwave, you need to keep it on longer because a microwave just heats the individual object.

“General equation is, find the wattage of an item, then work out how many kilowatts or what fraction of a kilowatt it's using, then multiply that by 34p per hour of use.”

Research from Which? agrees with Mr Lewis, that air fryers are the cheapest option for cooking most foods but “it is still better to use your oven if you’re cooking large quantities”.

Emily Seymour, the consumer group’s energy editor, said: “There has been a surge of interest in air fryers and smaller cooking appliances in recent months, and our research shows that the hype could be justified in some cases, as we’ve found these products cost less to cook certain foods than conventional ovens.

“The cost savings will soon be lost if you have to cook more than one batch though, so it is still better to use your oven if you’re cooking large quantities.”

Who is Martin Lewis?