Dr Amir Khan, an NHS doctor known for his TV appearances, has urged people to never throw away the watery liquid that forms on top of yoghurt, describing it as 'liquid gold' for the body. The liquid, called whey, is a natural part of the fermented food and is packed with protein and other nutrients.
What is the watery liquid in yoghurt?
While opening a tub of yoghurt, many people notice a layer of white, watery liquid on top. Although it can look unappealing and is often mistaken for a sign that the yoghurt has gone bad, it is actually a natural part of the product. Dr Amir Khan, who appears on ITV's Lorraine and Good Morning Britain, explained: "Guys, I just want to say, you know this watery stuff that develops on the top of yoghurt overnight and stuff? Don't throw it away."
He clarified: "I know it looks a bit odd, but it's actually meant to be there, and it's called liquid whey, and it naturally separates out from the yogurt because yogurt is a fermented food." Dr Amir reassured viewers: "Nothing's spoiled, nothing is split, nothing is bad, it's not fat," adding that it is actually packed with protein.
Benefits of whey protein
The watery liquid on top of yoghurt is called whey. Milk contains two main types of protein: whey and casein. When milk is fermented into yoghurt, the casein protein clumps up, forming the thick yoghurt, while whey protein remains liquid through a process called syneresis. This liquid is completely safe to eat and is not a sign that the yoghurt has spoiled. It contains mostly water but is also packed with nutrients, including protein, calcium, potassium, and B vitamins, while also being good for gut health.
Research indicates that incorporating whey protein into a regular diet can assist in building muscle mass, supporting hormone production, and maintaining bone strength. When combined with a balanced diet and consistent exercise, it can contribute to healthy and sustainable weight loss. Whey protein also provides a large amount of protein (typically 20–30 grams per serving) with very few extra fats or carbohydrates, especially in isolate form, while slowing down digestion and helping to reduce overall daily food intake.
"So don't pour it down the sink. I know it's really tempting. You're literally tipping away nutrients your body can use," Dr Amir said. "So just instead, mix it in into the yogurt and it is really, really good for you. It's just normal fermentation. That's what yogurt is." He urged viewers: "Anyway, mix it in, don't throw it away, and your body will thank you."
