Thursday Jan 1, 2015 (foodconsumer.org) -- Raspberry ketone is commonly used in diet pills or weight loss pills.   Readers need to know that like many other dietary supplement indented for weight management, raspberry ketone has not be tested in human trials for its efficacy in obesity prevention or treatment.  Even if this ingredient is indeed effective, nutritional supplement manufacturers dare not claim the efficacy because dietary supplements are not drugs and they are not intended to diagnose, treat, cure or prevent any disease.

However, like many other active natural antiobesity compounds, preliminary research generated evidence in Korea, China and Japan among others that suggests that raspberry ketone is promising in preventing and even treating obesity in animals fed a high fat diet.

Park in South Korea reported in Planta Med in 2010 that raspberry ketone increases lipolysis and fatty acid oxidation, which means that the compound can potentially promote fat burning.  Both lipolysis and fatty acid oxidation are two chemical processes involved in fat burning.  So some manufacturers may call raspberry ketone a fat burner. 

Most recently, Park again reported in Pharm Biol. that raspberry ketone inhibits adipogenic and lipogenic gene expression.  This means that this ingredient may help prevent the development of obesity.  Together, his studies indicate that raspberry ketone can not only promote fat burning to help treat obesity or induce weight loss or fat loss, but also prevent obesity in the first place.

Morimoto and colleagues in Japan also reported in 2005 in Life Science that raspberry ketone prevents and improves obesity and fatty liver in mice fed a high fat diet.   The Western diet used by many Americans is a high fat diet.  That is, the diet contains more than 30% of total calories from fat, either from vegetable oil or animal adiposity.  The study suggests that raspberry ketone may help prevent obesity and fatty liver in individuals following a high fat diet.  Their findings were pretty much confirmed by Wang and colleagues in China. 

In addition to its antiobesity effect, raspberry ketone may also help prevent nonalcoholic steatohepatitis, which can be induced by a high fat diet.   In 2014, Wang and colleagues in China reported that raspberry ketone "had a dual effect of liver protection and fat reduction" and the mechanism may involve alleviation of fatty degeneration of liver cells, reduction of liver inflammation, improvement of dyslipidemia and reversal of leptin and insulin resistance and improving antioxidant capacity.

Although raspberry ketone is promising as a weight loss ingredient, much research is needed to confirm its efficacy and safety in humans.   Raspberry ketone is a flavor ingredient that is generally recognized as safe (GRAS) by the Food and Drug Administration.

Raspberry ketone as a weight loss diet pill is commonly available at the supplement market or your local healthstore.

Other potential bioactive ingredients that are used in weight loss pills such as include garcinia cambogia (hydroxycitric acid), caralluma, forskolin, green coffee bean extract (chlorogenic acid), white kidney bean extract, konjac (glucomannan), phenethylamine, and yacon.