Myprotein Impact Diet Whey
The number to hold on to here is 59g of protein per 100g, not the 36g on the front of the bag.
- Protein blend
- 59g
- Protein / 100g
- 36g
- Per 60g scoop
- 92p
- Per 25g protein
- £107.99
- 5.00kg pack
How the numbers stack up against the price
92p buys 25g of protein here, which makes it the 12th cheapest of the 24 powders we have reviewed, behind PER4M Nutrition Isolate Zero at 86p, and 2p under the median.
That 36g is a 60g serving, two scoops, twice the powder a normal whey shake uses, so a 1kg bag is about 16 shakes rather than 33. Judge it on that basis and it stops looking like a bargain and starts looking like what it is: a meal-replacement-style blend with oat flour, inulin and 7.9g of fibre per 100g, plus green tea extract, CLA and choline for the "diet" positioning. The fibre and the slower carbs genuinely do keep you fuller than whey and water, which is the real reason to buy it if you are cutting and struggling between meals. If all you want is protein for the least money, this is the wrong product and plain Impact Whey is the right one.
Cost per 25g of protein, across our 24 reviews
Median 94p
- Protein Works Vegan Pea Protein - BLACK Innovation39p
- Protein Works Vegan Protein 360 - GOLD Innovation44p
- Protein Works Vegan Protein 360 - PLATINUM Innovation54p
- Bulk Pure Whey Protein70p
- Protein Works Whey Protein 360 - PLATINUM Innovation71p
- Protein Works Whey Protein 360 - GOLD Innovation72p
- PhD Nutrition Diet Whey73p
- NXT Nutrition Beef Protein Isolate74p
- Protein Works 100% Micellar Casein - BLACK Innovation82p
- PER4M Nutrition Whey Protein85p
- PER4M Nutrition Isolate Zero86p
- MyProtein Impact Diet Whey92p
- MyProtein Clear Whey Protein96p
- USN Blue Lab Whey100p
- Bulk Pure Whey Isolate£1.05
- MyProtein Impact Whey Protein£1.09
- MyProtein Impact Whey Isolate£1.22
- Applied Nutrition ISO XP£1.24
- Applied Nutrition Critical Whey£1.25
- Warrior Whey£1.26
- Bulk Clear Whey Isolate£1.33
- Protein Works Clear Diet Whey Protein - GOLD Innovation£1.37
- Scitec Nutrition 100% Whey Protein Professional£1.49
- Protein Works Diet Whey Protein Isolate - BLACK Innovation£1.56
Cheapest in-stock listing at a partner retailer, for packs of 400g and over.
The protein blend is 76% of the powder, and the other 24% is what makes it a "diet" product: oat flour, inulin, flaxseed, a CLA preparation, green tea extract, choline and a digestive enzyme complex. That is why protein per 100g lands at 59g rather than the 70g-plus a straight whey manages.
Impact Diet whey protein could be clearer in advertising serving numbers.
What the label gets right, and wrong
Strengths
- 7.9g of fibre per 100g, which is why it sits better between meals than a plain whey
- A three-protein blend of concentrate, milk protein and isolate, so it digests over a longer window
- Genuinely filling if you are using it as a meal stand-in on a cut
- Sold in 1kg, 2.5kg and 5kg, so the per-serving cost comes down if you commit
Watch-outs
- The advertised 36g of protein is a 60g double scoop. Per 100g it is 59g, well below a standard whey
- A 1kg bag is roughly 16 servings at the stated scoop, not the 30-plus you get from a whey of the same weight
- Our own catalogue lists 65g per 100g for this product. The label says 59g, and the label is right
- 6.1g of fat per 100g, most of the way to double a standard concentrate
Where to buy it
Ordered by cost per 25g of protein, because pack sizes and protein densities differ enough that a headline price on its own does not tell you which is better value.
| Retailer | Size | Price | Per 25g | Go to retailer |
|---|---|---|---|---|
| MyProtein | 5000g | £107.99 | 92p | View deal ↗ |
| Amazon UK | 1000g | £31.97 | £1.35 | View deal ↗ |
2 partner retailers stock a 400g or larger pack of this product.
Price history
What a scoop actually contains
Taken from the manufacturer’s published label. Source.
Read the serving size before the protein claim. The 36g figure is a 60g serving, which is two scoops, so it uses twice the powder of a standard whey shake. Our own scraped row says 65g per 100g and the published label says 59g. We use the label.
| Nutrient | Per 100g | Per 60g |
|---|---|---|
| Protein | 59g | 35.4g |
| Energy | 359 kcal | 215 kcal |
| Carbohydrate | 13g | 7.8g |
| of which sugars | 4.6g | 2.8g |
| Fat | 6.1g | 3.7g |
| of which saturates | 2.6g | 1.6g |
| Fibre | 7.9g | 4.7g |
| Salt | 0.35g | 0.2g |
Ingredients and formulation
Protein sources, in label order
- 01Whey protein concentrate (milk)
- 02Milk protein concentrate
- 03Whey protein isolate (milk)
Sweeteners and emulsifier
Sucralose
Soya lecithin and sunflower lecithin
Pack sizes
1kg · 2.5kg · 5kg
Dessert-style flavours in the main. Buyers rate the vanilla and strawberry shortcake; the recurring complaint is sweetness rather than any specific flavour failing.
Third-party testing
Certification is per programme and often per flavour or per batch, so a badge on one product does not carry across a brand’s whole range.
Not claimed on the product page. Worth flagging on this product in particular, because it contains green tea extract and CLA rather than whey alone.
Made by
MyProtein, a brand of THG plc, Manchester
Taste and what buyers report
Quoted and linked, so you can read the full thread.
“Impact Diet whey protein could be clearer in advertising serving numbers.”
“The vanilla diet whey is good flavour but over £50 for 2.5kg is steep.”
“Impact Diet Strawberry shortcake, it was delicious!”
What the maker does not publish
- Myprotein does not state a dose for the green tea extract, the CLA preparation or the choline anywhere we could find, so there is no way to judge whether the amounts are meaningful.
- Public review volume naming this product specifically is low compared with Impact Whey and the isolate, so the sentiment block below is thinner than we would like and should be read as such.
Questions buyers ask
The things people search for about MyProtein Impact Diet Whey, answered from the label and the live partner prices rather than from the brand’s own copy.
How much protein is in Myprotein Impact Diet Whey?
59g per 100g. The 36g figure on the marketing is a 60g serving, which is two scoops. A standard whey shake uses 30g of powder, so compare like for like before deciding this is the higher-protein option.
Does Impact Diet Whey help you lose fat?
Not on its own. What it actually does is keep you fuller, because of 7.9g of fibre per 100g and the oat flour and inulin in the blend. The green tea extract and CLA are the reason it is called a diet whey; the fibre is the reason it works for people. Fat loss comes from the deficit.
Is Impact Diet Whey better value than Impact Whey?
No, and it is not close. Impact Whey is 72g of protein per 100g in a 30g scoop; this is 59g per 100g in a 60g scoop. You get roughly half the servings from the same weight of bag. Buy this one because you want the fibre and the fullness, not because you want cheap protein.
Can you take Impact Diet Whey if you are drug tested?
We found no third-party batch testing for it, and unlike a plain whey it contains green tea extract and a CLA preparation. If you compete under testing, use a batch-tested product instead.
Reviewed next to
PhD Nutrition
Diet Whey
68g protein per 100g against 59g here, if density is what you are after.
73p / 25g protein
Protein Works
Diet Whey Protein Isolate - BLACK Innovation
86g protein per 100g against 59g here, if density is what you are after.
£1.56 / 25g protein
MyProtein
Impact Whey Protein
72g protein per 100g against 59g here, if density is what you are after.
£1.09 / 25g protein
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Last updated 8 September 2026