Raspberry Ketones are a chemical compound found in Raspberries. They became popular after an American TV show promoted them as a “Miracle fat-burner in a bottle”. Ever since then the supplement industry has been all over Raspberry Ketone diet as the latest super-pill that can make you lose fat without doing anything.

But do Raspberry Ketones actually do anything?

I took a look through the research to find out.


The first study I looked at was one by Lopez et al (2013) which found that Ketones when combined with other supplements (ginger, caffeine, garlic, capsaicin and a few others) did produce greater fat losses when combined with exercise than the placebo group [1].

The problem with this is, how do we know whether it was the Raspberry Ketones that produced the results? It could have been the caffeine (which has loads of evidence supporting its effect on fat-loss) [2][3] or the capsaicin [4]. My point is that when a product has so many different ingredients it is hard to point to just one and say “look this one was the ingredient that produced the result”.

I next looked at a study by Morimoto et al (2005) that found that Raspberry Ketones increased lipolysis (the breakdown of fats) and thermogenesis (raising of body temperature). Good news right? Well the study was done on rodents rather than humans, and the dose given was very high [5]. Too high, for realistic human consumption.

Another study on rodents by Park (2010) found that Raspberry Ketones stimulated lipolysis and fatty acid oxidation. Which means they helped burn fat [6].

Finding studies that used a normal dosage (one that humans could realistically take) of raspberry ketones that actually produced results proved problematic. A study by Salacinski et al (2015) looked at raspberry ketones and a metabolic activator blend, and their effect on resting metabolic rate. The study found that there was no significant effect on weight loss [7].

raspberry ketone diet_2

The problem with Raspberry Ketones is that they are seen as the latest miracle cure by a general public who is tired of being overweight but doesn’t want to have to work hard for fat loss.

This is not a criticism, fat-loss is difficult and time consuming. Shouldn’t we as a species have invented a quick and effective pill that can solve this issue by now?

Even if Raspberry Ketones did work, they would never be a long term solution. They would be treated like crash dieting and used with 6 weeks left before a holiday as a last-gasp solution. The supplement industry will never stop selling these miracle cures, no matter how much science discredits them.

Look at the Cambridge diet, or Atkins. See meal replacement shake companies who sell poor quality protein shakes to eager customers who just want to look good. This is not health, this is big pharmaceutical companies praying on the desperate.

We’re all the same!

And aren’t we all desperate? I’m a personal trainer and fitness writer, I have made my career out of getting people to follow the sensible, patient approach to fat loss. But if you gave me a pill that would instantly transform myself into one of those Instagram models with the sexy abs that I see every day, I would bite your hand off  – to save time grabbing the pill out of it!

Raspberry Ketones and other such fat-loss pills are never going to be the answer and believe me I am as gutted about that as anyone. Exercising regularly, walking your 10,000 steps per day, and eating less calories than you burn is the only real “Fat loss solution” and sadly you can’t bottle it.

Connect here with WatchFit Expert Matthew Smith!


[1]Lopez, H., Ziegenfuss, T., Hofheins, J., Habowski, S., Arent, S., Weir, J., Ferrando, A. 2013. Eight weeks of supplementation with a multi-ingredient weight loss product enhances body composition, reduces hip and waist girth, and increases energy levels in overweight men and women. Journal of the International Society of Sports Nutrition 10:22

[2] Dulloo, A., Duret, C., Rohrer, D., Girardier, L., Mensi, N., Fathi, M., Chantre, P., Vandermander, J. (1999) Efficacy of a green tea extract rich in catechin polyphenols and caffeine in increasing 24-h energy expenditure and fat oxidation in humans. American Society for Clinical Nutrition 70(6): 1040-1045

[3] Rumpler, W., Seale, J., Clevidence, B., Judd, J., Wiley, E., Yamamoto, S., Komatsu, T., Sawaki, T., Ishikura, Y., Hosoda, K. (2001) Oolong Tea increases Metabolic Rate and Fat Oxidation in Men. The Journal of Nutrition 131(11): 2848-2852

[4] Diepvens, K., Westerterp, K., Westerterp-Plantenga, M. 2007. Obesity and thermogenesis related to the consumption of caffeine, ephedrine, capsaicin, and green tea. American Journal of Physiology – Regulatory, Integrative and Comparative Physiology 292(1): R77-R85

[5] Morimoto, C., Satoh, Y., Hara, M., Inoue, S., Tsujita, T., Okuda, H. 2005. Anti-Obese action of Raspberry Ketone. Life Sciences 77(2): 194-204

[6] Park, K. 2010. Raspberry Ketone increases both Lipolysis and Fatty Acid Oxidation in 3T3-L1 Adipocytes. Planta Med 76: 1654-1658

[7] Salacinski, A., Howell, S., Hill, D. 2015. The Acute Effects of Non-stimulant Over-the-Counter Dietary Herbal Supplements on Resting Metabolic Rate. Journal of Dietary Supplements 13(4): 368-377


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