In a TikTok video to his 5.2 million followers, Doctor Karan Rajan, a surgeon working for the NHS in the UK, revealed the simple hack.

“If you take a slice of white bread and toast it, you end up lowering the glycaemic index (GI) of the bread,” Raj explained in a viral clip that has so far generated over a thousand comments.

What is the GI?

The GI is a rating system for foods containing carbohydrates. It shows how quickly each food affects your blood sugar (glucose) level when that food is eaten on its own.

Carbs that are broken down quickly by your body and cause a rapid increase in blood glucose have a high GI rating. White bread is one of the worst offenders on the index.

However, by freezing, defrosting and then toasting white bread, you actually lower’s the item’s glycaemic response (the effect it has on blood sugar levels after consumption), the doc explains.

“This all happens because more retrograded starch is formed, and retrograded starch is a type of resistant starch which is beneficial for your gut health because it acts more like a fibre,” Doctor Rajan continued.

Essentially, the process makes it more difficult for the enzymes to break the starch down into sugar.

The TikTok video was met with glee and wonder, with one user writing: “This is the life advice I need!”

A second viewer wrote: “I always freeze my bread for toasting, so there’s no waste. Didn’t realize it was beneficial”, while another follower was wryly sceptical: “Also if you freeze bread, defrost it, toast it, then bin it, you get zero glycemic load.”

What the research says

Research is limited but one small study, published in the European Journal of Clinical Nutrition, does support Doctor Rajan’s claim.