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.uk

Presenter: Greg Foot Producer: Julian Paszkiewicz