Raspberry Ketones Review: I Smell a Rat

A few days ago I noticed an advertisement for a new “weight loss supplement”: raspberry ketones.  This one has apparently been endorsed by Dr. Oz and is being advertised all over the internet.

I’ll tell you what the research really says, but let’s first talk about fat loss pills/supplements in general.  There are basically three ways a drug or chemical can aid in fat loss:

  • 1. Decrease/suppress appetite
  • 2. Prevent absorption of calories
  • 3. Aid in lipolysis (the breakdown of fat)

Is there any evidence this supplement does any of these three things?  One study demonstrated raspberry ketones had a protective effect on the health of rats that were fed a high fat diet.1  Yes–all this hype over studies on rodents. I’m not aware of any research clearly demonstrating this supplement’s effectiveness for humans in losing weight.

I wish I could say I was surprised, but quoting inappropriate research (like animal studies) has been a favorite tactic of supplement manufacturers for a long time.

Raspberry ketones could be be a good source of antioxidants (assuming they are processed correctly). 2 But that is not the way they are being marketed–at least not in the advertisements I am seeing.

My Recommendation:

I wouldn’t spend any money on this kind of supplement.  Look into a good diet and exercise program if you are really wanting to lose weight.

References:

1. Life Sci. 2005 May 27;77(2):194-204. Epub 2005 Feb 25. Anti-obese action of raspberry ketone.

2. J Agric Food Chem. 2011 Dec 15. [Epub ahead of print] Comparison of Flavonoid Composition of Red Raspberries ( Rubus idaeus L.) Grown in the Southern United States.

Bro Science and Bodybuilding Myths


One important term you need to learn (if you haven’t already) in the realm of fitness and bodybuilding is bro science.  This refers to anecdotal evidence or pseudo-science being treated as legitimate research.

Bodybuilding myths are often passed around on forums, where everyone offers their “expert” advice.   Ironically, some people will get really upset when you challenge their claims with solid research.  I’m not sure why some are so emotionally attached to certain diets and methods.

I believe some diet/training misinformation has been intentionally propagated by supplement companies.  They have made millions playing on our fears catabolism and giving false hopes of performance enhancing “tips.”

I’ll admit it–I used to believe many bro science myths.  But writing about fitness has taught me to research more carefully.

Here are a few myths I no longer believe and what I now practice (you can click some of the linked articles for more complete explanations):

Myth: “Breakfast is the most important meal of the day.”

I regularly skip breakfast since I started practicing intermittent fasting.  Breakfast is important if it helps you stay compliant with your diet, but it isn’t metabolically necessary to eat when you wake up (see: Breakfast and Weight Loss).

Myth: “You need 1.5 to 2 grams of protein per lb. of body weight to gain muscle.”

Reading How Much Protein by Brad Pilon really shed some light on this for me.  I now eat about 90-110 grams a day (sometimes less) and I haven’t lost any size or strength.  The only real difference I’ve seen is in my wallet–I’ve saved a lot of money on protein supplements (I still use them, but not as much).

Myth: “Your muscles are starving after training and you need to take a protein/carbohydrate shake.”

Yes, training does lower glycogen stores, and it makes sense to refill them.  But one training session doesn’t put your body into some kind of “starvation mode,” and I’m not convinced there’s any serious advantage to drinking a protein shake after you train.

Holding off on your post workout meal may, in fact, help burn more fat and get leaner (one of the strategies in the Renegade Diet).  You can see my article on post workout protein to see my argument for slower digesting proteins (like milk) after you train.

Myth: “Eating frequent, small meals fires up your metabolism.”

There is no metabolic advantage to eating six meals a day.  Small, more frequent meals may help a trainee stay within his/her optimal daily calorie requirements, but that is a compliance issue–not a metabolic one.

Myth: “Don’t eat carbs after 6:00 p.m.”

Eating carbs at night will not make you fat if you are achieving a negative calorie balance.  I’m actually having a much easier time staying lean by eating most of my carbs during dinner (Renegade Diet strategy).

Let me clarify something:  Eating frequent small meals or avoiding late-night carbs may work well for you (as well as following any other before-mentioned “rule”).  And further research may reveal something we are missing right now.  But be careful about treating one strategy as the only strategy, and do your best to understand why something works.

Bro Science and Supplements

Here’s where you have to be really careful.  Supplement companies are skilled at writing up articles with convincing terminology to explain why you should take their pill, powder, or capsule.  But most supplements just don’t make any real-world difference when put to the test of a double-blind, placebo-controlled study.

In conclusion: do your research, keep an open mind, and be cautious about what you accept as fact (and be even more careful about how you spend your money).