Biotic's Gain

Plant protein powders and whey are both concentrated protein, and across a day’s eating they do much the same job: they add protein to a meal that would otherwise be short of it. The differences are real but narrower than the marketing suggests. Plant powders are usually pea, soy, rice, hemp or a blend of those; whey is a dairy fraction left behind by cheesemaking. Whey is a little more digestible and carries more leucine, while a sensible plant blend closes most of that gap by pairing a pulse with a cereal. In practice taste, cost, how it mixes and whether you eat dairy will decide it long before the amino acid table does.

What a plant protein powder is actually made from

Almost every plant powder on a UK shelf starts as a crop grown for something else. Pea protein comes from the yellow split pea, milled and then separated from its starch and fibre until the remaining powder is roughly four-fifths protein. Soy protein isolate is made from defatted soy flour and sits a little higher again. Brown rice protein is produced by treating milled rice with enzymes so the starch can be washed away. Hemp protein is the pressed seed cake left after oil extraction, which is why it stays nearer half protein and keeps a noticeable amount of fibre and fat. Fava bean, pumpkin seed and potato protein turn up in smaller quantities, usually inside a blend.

That word blend matters more than the hero ingredient on the front of the tub. A single-source pea powder and a pea-and-rice blend are different products with similar labels, and the blend exists for a reason worth understanding rather than ignoring. Whey, by comparison, is a single stream: the liquid left when milk is separated for cheese, filtered and dried. A concentrate keeps more of the milk fat and lactose; an isolate has been filtered further, so there is less of both and a higher proportion of protein by weight.

Amino acids: where the real difference sits

Protein is a long chain of amino acids, nine of which the body cannot make for itself. Nearly every plant protein contains all nine, so the common claim that plant foods are missing amino acids is wrong as stated. What varies is the proportions. Pulses such as peas and beans run low on methionine; cereals such as rice, wheat and oats run low on lysine. Put one of each in the same tub and the shortfalls cancel out, which is exactly why pea-and-rice is the most common blend on the market. Soy is the outlier among plants in that its profile already sits close to a dairy protein without help.

The second difference is leucine, the amino acid most studied in connection with muscle. Whey is unusually rich in it, at around a tenth of its protein by weight, while pea and rice sit nearer eight per cent. Over a 25 to 30 gram serving that gap is a fraction of a gram, and it is worth being plain about what that does and does not mean: there is no authorised claim in Great Britain ranking plant protein against animal protein, in either direction, so anyone who tells you one is better full stop has gone past what the register allows. The honest version is that the numbers differ a little and a slightly larger plant serving evens them out.

• Pea: higher in lysine, lower in methionine, neutral-earthy taste.
• Rice: the mirror image, lower in lysine, which is why the two are blended.
• Soy: the most complete-looking plant profile on its own.
• Hemp: lower in protein per scoop, higher in fibre and fat.
• Whey isolate: highest leucine share and the most filtered of the group.

Digestibility, and how to read the figures

Digestibility describes how much of the protein you swallow is absorbed rather than passed. Animal proteins, whey among them, are usually measured in the low-to-mid nineties. Whole pulses and grains sit well below that, in the seventies and eighties, because fibre and anti-nutrients get in the way. The useful detail is that isolating a plant protein removes most of what was slowing it down, so a pea or soy isolate measures far closer to dairy than a tin of chickpeas does. The sensible response is not to worry but to aim a little above whatever daily figure you were working to, which costs a spoonful rather than a rethink.

Texture, taste and how they mix

This is the difference people actually notice. Plant powders are thicker and grainier in water; pea and rice have an earthy note that flavouring covers rather than removes, hemp is openly nutty, and soy is the most neutral of them. Whey isolate mixes thin and clears quickly, which is why it suits a shaker and a glass of water. Both behave differently in cooking: plant powders soak up liquid and suit porridge, overnight oats and thick batters, while whey tightens and can go rubbery if it is baked too hot for too long. If you have found whey heavy in the past, an isolate is the version with the least lactose left in it, which is a composition point rather than a health one.

What anyone is allowed to say about protein

Great Britain keeps a register of authorised nutrition and health claims, and protein has its own entries. They belong to the nutrient, not to any brand, flavour or source, which means a tin of lentils, a pea isolate and a tub of whey all stand on exactly the same wording:

Protein contributes to a growth in muscle mass. Protein contributes to the maintenance of muscle mass. Protein contributes to the maintenance of normal bones.

Those sentences are conditional on the food qualifying: protein has to supply at least twelve per cent of the energy in the product for it to be called a source of protein, and twenty per cent for high in protein. The word normal cannot be dropped, and it cannot be traded up for improved, stronger or faster. There is no authorised claim specific to whey, and a long list of proposed whey claims was rejected outright, so a whey product that promises you something beyond the three sentences above has gone off the register. We only quote claim wording we have checked against the Great Britain register ourselves, which is why you will not find us attaching a claim to the plant or animal argument at all.

Where the Whey Protein Isolate sits

Our own powder is Biotic’s Gain Whey Protein Isolate: a 2lb tub, 25g of protein and 5.5g of BCAAs per serving, in six flavours. It is filtered further than a concentrate, so it carries less fat and lactose, and it is dairy, which makes it vegetarian but not vegan. That is a description of what is in the tub rather than a promise about what it will do for you, and if you avoid dairy entirely then a pea-and-rice blend is the shelf to be looking at instead.

Choosing between them

• Avoiding dairy, or vegan: a pea-and-rice blend or soy isolate.
• Want the thinnest drink in water: whey isolate.
• Mostly cooking and baking with it: plant powders hold liquid better.
• Counting grams closely: read protein per serving, not per tub.
• Single-source plant powder: check it is paired with something in the rest of your day.
• Still deciding: buy the smallest tub of either and judge it on taste.

More on the daily figures and where protein comes from on our protein guide.

Biotic’s Gain human products are food supplements, not medicines, and are no substitute for a varied diet and a healthy lifestyle. Nothing here is medical advice. If you are pregnant or breastfeeding, taking prescribed medication or living with an existing condition, speak to your GP or pharmacist before starting any supplement.