Diet Whey vs Non-Diet for Weight Loss

Diet bars, lean wheys, mass gainers. Some supplements scream out what their target audience is! A lot of people will pick up on those buzz words and automatically go for the product that promises to help them reach their goal. But do we understand why? Let's talk about why certain proteins are labelled this way, what makes them different, and how significant those differences are.


CLA. An ingredient commonly added to diet proteins is Conjugated Linoleic Acids (CLAs). CLA is an omega 3 fatty acid which is popular as a non-stimulant fat burning product, alone in capsules and liquids or added to products such as BCAAs and whey. CLA has been linked to reducing fat storage, increasing metabolism and an improvement in overall body composition, among other benefits. A 2001 study on healthy, exercising humans concluded that CLA reduces body fat but not body weight (this is likely down to an increase in muscle mass). Unfortunately, however, there seem to be just as many studies showing little to no effect with CLA supplementation. We advise you to make your own conclusions with this one while we wait on more solid data!

Green Tea. Green tea, both as an extract and a drink, is a favorite with the dieting population. Green tea is undeniably great for health. As a drink, it is calorie free, and can be sweetened to taste if desired. It is loaded with antioxidants from its high polyphenol content, which protect against cell damage from the atmosphere and contains caffeine, but at a lower dosage than coffee. Caffeine itself can work as a fat burner in those with a low tolerance. PhD diet whey contains 7mg of caffeine per 25g of powder, not really enough to have an effect alone- for these properties, consider also drinking 1-2 cups of the stuff early in the day! It has been suggested that the flavonoids and caffeine in green tea can increase metabolic rate, increase fat oxidation (breakdown improve insulin activity. Although these increases are only very mild, green tea does enough great things in the body for it to be worth trying.

L-Carnitine. L-Carnitine is an amino acid like substance found naturally in the body. L-carnitine helps to transport fat, particularly long-chain fatty acids, into the mitochondria of cells, hence the claims that it may assist the breakdown of body fat and, hypothetically, work well with CLA. Some people cannot make enough, so will see greater benefits from supplementation. Studies on L-carnitine for fat loss and increasing insulin sensitivity are weak, but other benefits have been seen- even improving sperm quality in men! L-carnitine is taken up best with carbs. If using a diet whey with L-Carnitine, consider adding it to your oats!

Fibre (Glucomannan in CNP Diet Whey, Flaxseed in PhD and CNP Diet Whey). Glucomannan helps to keep you feeling fuller for longer. This can reduce cravings and increase adherance to a diet. Glucomannan will also help maintain normal blood cholesterol levels and improve gut and bowel health. Authorised by EFSA, Glucomannan is one of the few ingredients available that can be stated to facilitate weight loss. Flaxseed is another fibrous ingredient with the added benefit of being high in omega 3 healthy fats.

Low Fat. Most diet whey products contain only around 1-2g fat per serving. This helps to keep the calories down, and is also something that dieters commonly look for on food labels. This is in conjunction with high protein content and low-moderate carbs depending on product.


While there is inconclusive evidence on whether any of these ingredients will increase the rate of fat loss, they certainly won't do any harm in the dosages used. Having 'diet' products may also increase motivation and act as a sort of placebo, causing you to stick to a calorie controlled diet and be more active. Think of these as supporting fat loss, not causing it.
If the product is good value compared to a more basic whey, it is worth trying.

Thom, E., Wadstein, J. and Gudmundsen, O. (2001). Conjugated Linoleic Acid Reduces Body Fat in Healthy Exercising Humans. Journal of International Medical Research, [online] 29(5), pp.392-396. Available at: [Accessed 19 Sep. 2018].

About the Author

Savannah Westerby. BSc Sport and Exercise Nutrition. Instagram: @savannahwesterby

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