Whey is an animal-based protein that comes from milk, most often as a by-product of making cheese. It's in a huge share of protein powders, bars and shakes. Here's what it is, how it's made, the main forms you'll see on labels, and why some people choose a plant protein instead.
Where does whey come from?
Milk contains two main families of protein. Dairy protein is about 80% casein and 20% whey. When milk is made into cheese, the casein forms the curds and the whey is left in the liquid. That liquid whey is mostly water, with some protein, lactose, fat and minerals.
To make whey protein powder, the liquid is filtered to remove much of the water, lactose and fat, then dried. Whey is known as a "fast" protein because it's digested and absorbed quickly, while casein is digested more slowly.
What are the different types of whey protein?
You'll usually see one of three forms on a label:
- Whey protein concentrate keeps more of the lactose and fat, so its protein content per gram is lower and varies from product to product. Read more in what whey protein concentrate is.
- Whey protein isolate is filtered further to remove most of the lactose and fat, so it's higher in protein per gram.
- Whey protein hydrolysate has been partly broken down with enzymes, sometimes described as "pre-digested."
All three are processed foods, which isn't a problem in itself. What matters is what else is in the tub and whether it agrees with you.
Can whey cause bloating or gas?
It can, mainly because of lactose. Experts estimate that about 68% of the world's population has lactose malabsorption, and people with lactose intolerance can get bloating, gas and diarrhea after dairy. Isolates contain less lactose than concentrates, but they aren't lactose-free.
Milk is also one of the nine major food allergens in the US, and whey is one of the milk proteins that can trigger a reaction. A milk allergy is an immune response and is different from lactose intolerance; if you suspect one, talk to a doctor. For a closer look at the downsides, read is whey bad for you? and can whey protein make you sick?
What's a whey-free alternative?
A plant protein blend can give you a complete amino acid profile without dairy. So Lean & So Clean provides 23g of complete organic plant protein per serving from organic pea and rice protein, plus two servings of organic greens, with no added sugar and no artificial sweeteners, fillers or gums.
