Sliced Bread

It seems like everyone’s talking about air fryers. They were recently dubbed the product that defined 2021, with sales up by 400%. But how do they fry with air?Listener Sally in Harrogate has another question too: at a time when the cost of living is rocketing will cooking with an air fryer save her money? And, because they use little to no oil, is cooking food in an air fryer also “healthier”? Greg Foot investigates, speaking to a food scientist at Imperial College London and the BBC’s Good Food Magazine, to find out whether the claims being made around air fryers live up to the hype or are just marketing BS.This series, we’re testing your suggested wonder-products. If you’ve seen an ad, trend or fad and wonder if there's any evidence to back up a claim drop us an email to sliced.bread@bbc.co.uk or you can send us a voice note to our new WhatsApp number: 07543 306807PRESENTER: Greg Foot PRODUCER: Simon Hoban

Air purifiers have become one of the most popular home gadgets in recent years and you can spend hundreds of pounds on the top-end models. They promise to remove harmful pollutants in the air, reduce the symptoms of allergies and help you breathe more easily in a more healthy environment. But what's the evidence around how effective they are? Listener Laura, a respiratory doctor, got in touch wanting to know whether they work and even if they could help some of her patients in their daily lives. Greg Foot investigates the science behind the product, speaking to experts to find out just how many pollutants are being pulled from thin air, the effective range of air purifiers and whether there are any downsides to how they work.This series, we’re testing your suggested wonder-products. If you’ve seen an ad, trend or fad and wonder if there's any evidence to back up a claim drop us an email to sliced.bread@bbc.co.uk or you can send us a voice note to our new WhatsApp number: 07543 306807PRESENTER: Greg Foot PRODUCERS: Kate Holdsworth and Julian Paszkiewicz

Brands are promising to plant a tree for each can of beer, tshirt, or pair of trainers you buy, offsetting their carbon emissions so they can put an attractive ‘carbon negative’ sticker on a product to show green they - and you - truly are. But how effective is a new forest at offsetting a company’s emissions, what does ‘carbon negative’ really mean, and how do they go about proving they’ve achieved it? Trees are just one type of carbon offset. Another, albeit promising but expensive, option is Direct Air Capture. Could that be the future of long term carbon offsetting? Greg Foot finds out. This series, we’re testing your suggested wonder-products. If you’ve seen an ad, trend or fad and wonder if there's any evidence to back up a claim drop us an email to sliced.bread@bbc.co.uk or you can send us a voice note to our new WhatsApp number: 07543 306807PRESENTER: Greg Foot PRODUCER: Simon Hoban

Huel and Soylent are two of the best known names in ‘complete nutrition’ drinks. More of us are trying them and you can now get pre-made bottles of these concoctions in the food aisle in supermarkets. Firms sell them as an instant alternative to breakfast, lunch and dinner too. But how ‘nutritionally complete’ are these liquid lunches? Listener Tom admits snacking on one in the middle of the afternoon but has questions. Does the fact they start as an ultra processed powder affect how healthy they are? Is it possible to live on them and nothing else? Greg Foot investigates. He talks to a registered dietician, a researcher on a new trial into these products, and Huel's co-founder and Head of Sustainable Nutrition, James Collier. In this series, we’re testing your suggested wonder-products. If you’ve seen an ad, trend or fad and wonder if there's any evidence to back up the makers' claims drop us an email to sliced.bread@bbc.co.ukPresenter: Greg Foot Producer: Julian Paszkiewicz

Take a look down the aisle of any high street chemist and the array of electric toothbrushes on offer is as dazzling as the teeth they promise to give you. You can pay upto £500 for the latest versions whiose myriad features include interactive apps that give you feedback on your brushing technique.The market is dominated by two big brands, both promising a ‘professional’ clean: Oral B, whose iO brush has an oscillating action and Philips’ Sonicare, which uses tens of thousands of vibrations every minute to clean your teeth.After having to pay a lot more for private treatment because she couldn’t find an NHS dentist in her area, listener Holly got in touch to ask whether getting an electric brush might save her trips to the dentist in future. And wouldcould a more expensive brush really clean her teeth better than a cheaper electric one? Or even the trusty traditional (and far cheaper) manual one she currently uses?! Greg takes to the dentists chair to find out, testing both the Oral B and Philips brands as well as one of the latest trends – water flossing, which claim even better results than regular flossing with tape or interdental brushes. Is it the best thing since sliced bread? Or marketing BS? Greg guests this episode include a dental expert who's been studying electric brushes since their inception and the consumer group Which? who ranked electric toothbrushes in a recent consumer test of their own.This series, we’re testing your suggested wonder-products. Seen an ad, trend or fad and wonder if there's any evidence to back up the claim? Tell us! Drop us an email to sliced.bread@bbc.co.uk . PRESENTER: Greg Foot PRODUCER: Simon Hoban

According to some businesses, the laptop, phone and TV screens we use every day are causing us big problems. They claim these devices emit concentrations of "harmful blue light" which leaves us with tired eyes and poor sleep. One firm goes even further by suggesting this may contribute to a worrying long term condition, macular degeneration which leaves you with a permanent black hole in the centre of your vision.Their solution? A pair of trendy looking spectacles which claim to filter out this blue light. Listener, Sophie spends roughly 12 hours a day at a screen of some sort. She bought a pair but isn't sure if they work. So she's asked Greg to look into them and find out. We get answers from two leading lights in the science of our eyes. Professor John O'Hagan has been a public health scientist for 46 years and is Visiting Professor in Laser and Optical Radiation Safety at Loughborough University. Greg also meets sleep expert Russell Foster, professor of Circadian Neuroscience at the University of Oxford who's been researching body clocks for 38 years. We put the evidence directly to Dhruvin Patel. He's the boss of one of the largest blue light filtering brands, Ocushield which turned over £2m last year.How does he respond? And will Sophie keep using her trendy specs? This series, we’re testing your suggested wonder-products. Seen an ad, trend or fad and wonder if there's any evidence to back up the claim? Tell us! Drop us an line to sliced.bread@bbc.co.uk . Presenter: Greg Foot Producer: Julian Paszkiewicz

The vitamins market is growing fast, with many companies now offering bespoke vitamin plans that claim to produce the perfect personalised prescription just for you.Our listener Gareth wants to know if this could be a quick fix for his low energy and poor diet so Greg is going to find out. He’s got his sights on the popular companies suggesting personalised plans based on a simple online questionnaire that builds up a picture of your vitamin deficiencies via questions about your exercise, stress levels, diet and more.But these personalise plans comes at a premium - some go for close to £25 per month. Greg tests the questionnaires, speaks with nutritional experts, and sees whether Gareth thinks personalised vitamin plans are the best thing since sliced bread, or marketing BS.This season we’re testing YOUR suggested wonder-products. If you’ve seen an advert, trend or fad and want to know what the evidence says drop us an email to sliced.bread@bbc.co.uk or drop Greg a message direct on his social media where he’s @gregfootPRESENTER: Greg Foot PRODUCER: Simon Hoban

They cost anything from less than £20 to more than £250. So how do you pick the right pair? And will paying more make you run faster?With the ‘Couch to 5K’ app breezing past 5 million downloads, and marathon season well underway, two listeners ask Greg: What will they get for the extra money? A shoe more suited to their running style? More cushioning and fewer injuries? And will a top of the range pair with a carbon plate in the sole make them faster? Greg Foot gets the answers from biomechanist, Dr Hannah Rice and sports technologist Professor Mike Caine. Plus, running writer, journalist and world record holder [for the fastest marathon in a full body animal costume (female)], Kate Carter. This season we’re testing YOUR suggested wonder-products. If you’ve seen an advert, trend or fad and want to know what the evidence says drop us an email to sliced.bread@bbc.co.uk or drop Greg a message direct on his social media where he’s @gregfootPresenter: Greg FootProducer: Julian Paszkiewicz

One of your most requested ‘wonder-products’ so far. Heat pumps are promising to not only make our houses greener but to also cut our energy bills. But will they? The Government says every home could have one and have reintroduced grants to help buy them. However Nick wants to know if an air source heat pump would be suitable for the 1930s house he’s about to move into with his family. Given the higher cost of the unit and the extra insulation he needs, will he actually be better off with a new combi boiler instead? Greg speaks to experts, does a survey on his own home and gets Nick answers so he can decide if a heat pump, for him, would be the best thing since sliced bread. Do you have a suggestion of a ‘wonder-product’ making a bold claim that Greg can investigate next? Send us your suggestions to sliced.bread@bbc.co.uk or send it to Greg direct on twitter or instagram where he’s @gregfootPRESENTER: GREG FOOT PRODUCER: SIMON HOBAN

For many beef connoisseurs, a wagyu steak is the tenderest meat money can buy. They say it literally melts in the mouth. But Pete wants to know, if a Wagyu steak can set you back £100, how can supermarkets sell Wagyu burgers for around £3.50 a pair? How much of what makes wagyu beef so prized trickles down into a burger?Greg speaks to meat scientist, Martin Anderson, visits a Wagyu farm in Yorkshire, and sets up a blind taste test. All to find out if Wagyu burgers are the best thing between sliced bread. Do you have a suggestion of a ‘wonder-product’ making a bold claim that Greg can investigate next? Send us your suggestions to sliced.bread@bbc.co.uk or send it to Greg direct on Twitter or Instagram where he’s @gregfoot PRESENTER: GREG FOOT PRODUCERS: JULIAN PASZKIEWICZ & KEVIN CORE