USN Diet Fuel Ultralean

USN Diet Fuel Ultralean

USN Diet Fuel Ultralean










  • Great Protein Content
  • Tasty Flavours
  • Multiple Flavour Options
  • Leaves You Feeling Full

Diet Fuel Ultralean is a high-protein meal replacement shake from USN, designed to help you maintain your protein intake while cutting.

While I’m not a big advocate of replacing real food with shakes, I understand that people lead crazy busy lives and may not have time to cook real meals.

With that in mind, I stuffed my apron in a drawer, picked up a tub and got to work.


Active Ingredients

Whey Protein Concentrate, Maltodextrin, Soy Protein Isolate, HI-MAIZE® Resistant Starch, Fructose, Inulin, Milk Protein Isolate, Garcinia cambogia, Rice Starch, Garcinia Cambogia, Zinc Citrate, Nicotinamide, Manganese Ascorbate, Tolerase™L (pH-stable lactase), Copper Bisglycinate, D-Calcium Pantothenate, Retinyl Palmitate, Cyanocobalamin, Biotin, Cholecalcipherol, Pyridoxine HCl, Riboflavin, Thiamin HCl, Chromium Picolinate, Potassium Iodate, Folic Acid, Sodium Selenate.



The protein content in Diet Fuel Ultralean comes from a mixture of whey protein concentrate, soy protein isolate and milk protein isolate. That gives you a nice mix of quick and slow digesting proteins, which makes sense when you consider that it’s a meal replacement shake.

(The inclusion of a milk protein means you’re best to avoid it if you’re lactose intolerant or vegan.)

All in, each scoop (27.5g) contains about 17.7g of protein, 8.7g of carbohydrates and 1.3g of fat.

While the shake does have relatively high levels of carbs, the sugar content is actually pretty low. Just 1.3g of each  scoop is sugar. That said, it’d be nice to see lower GI sugar sources used in place of the fructose, maltodextrin and sucralose.

With meal replacement shakes, flavours are obviously pretty important so it was a bit disappointing to see just five flavours on offer: Vanilla, Chocolate, Strawberry, Banana Caramel and Caffe Late.

The Caffe Late shake tasted great but I can definitely see myself getting bored of it after a couple of weeks.



A 1kg tub of Diet Fuel Ultralean will set you back £31.99. At 55g per serving, you’re looking at around 18 servings before you need to restock.

Diet Fuel Ultralean works out at £1.78 per serving, which is actually pretty good value, especially when you consider that it’ll do a lot of the heavy lifting in hitting your protein macros.

If you bump up the tub size to 2kg, you’re looking at £1.61 per serving, which is bordering on damn cheap.




USN Diet Fuel Ultralean tasted great and left me feeling full for a few hours after my workout. My recovery wasn’t quite as horrible as I was expecting it to be, which was a nice surprise.

All in all, I’d recommend giving Diet Fuel Ultralean a go if you’re looking for a protein supplement for your cut.