A while back, I was listening to “talk radio” in my car and heard Dennis Prager say that olive oil helps to suppress appetite, leading to loss of excess weight. I only caught the tail end of it, and let it go. Evelyn Tribole, M.S., R.D. brought to my attention recently an article regarding hunger suppression by fatty foods, such as olive oil. I found the time to research Prager’s statement.
The olive oil/appetite suppression link seems to emanate from Seth Roberts, Ph.D., who was (and still is?) a psychology professor at the University of California - Berkeley. He self-experimented with the theory that sugar water or olive oil taken on an empty stomach suppresses appetite naturally. He stumbled upon his theory on a trip to France when he noticed that soft drinks unfamiliar to him seemed to suppress his appetite. His theoretical underpinnings are based on rat studies, and on the idea - not his own - that our bodies have a weight set-point that mostly determines our weight.
The set-point is like a thermostat that can be reset. Set-point theory explains that after a spell of weight loss, we usually return to our previous heavy weight because that’s where the thermostat (set-point) is set. We need to reset the thermostat. How do you do that? Drink either 1) one tbsp of extra light olive oil, or 2) one or two tbsp of fructose or sucrose (table sugar) in water, and do this not at mealtimes but at least one hour after meals, one to four times daily. Don’t eat anything else at the time of the supplement, nor for one hour thereafter. Total calorie content of these supplements is 100-400 calories per day. You experiment to find the dose that suppresses your appetite. And eat healthy meals of your choice. Dr. Roberts says the extra light olive oil is better than the sugar. Not extra virgin olive oil, which has too much flavor.
The pure, unadulterated sweetness of sugar, and the near-tastelessness of the olive oil are important, according to Dr. Roberts. They trick your weight set-point into resetting. At least this is the theoretical framework he gave to Prager and TheDietChannel.com in 2006. ABC News in 2005 reported he “suggests it works by suppressing a basic ‘caveman’ instinct from days when access to food was intermittent. The diet tricks the body from thinking it needs to eat every last bit of food before an impending famine.” My sense is: If it works, it works, and the underlying mechanism is less important.
Dr. Roberts easily lost 50 pounds with his method and wrote The Shangri-La Diet: The No Hunger Eat Anything Weight-Loss Plan to share with the world. The blogosphere and the authors of Freakonomics helped spread the word rapidly. In 2006, Dennis Prager allocated an entire hour of his show to Dr. Roberts, and volunteered that the olive oil indeed was suppressing his (Prager’s) appetite. According to the book reviewers at Amazon.com, the Shangri-La Diet clearly works miraculously well for some, not at all for others. You can find much more information and testimonials at www.sethroberts.net., perhaps enough that you don’t need to purchase the book if you want to give it a go. Last I checked, the paperback was $3.99 plus shipping at Amazon.com.
I’m not sure if this diet is a hoax or not. It’s possible it is a social psychology experiment. Maybe Dr. Roberts had a bet with someone that “anyone can write a popular diet book if they just use the formula.” You can find the formula at www.sethroberts.net under “Reviews and Media.” Listen to Dr. Roberts’ interview with Dennis Prager and decide for yourself. He sounds earnest.
I suspect it’s a hoax but, then again, Dr. Roberts may himself be a true believer. What’s the evidence for hoaxiness? The subtitle was my first clue: The No Hunger Eat Anything Weight-Loss Plan. Legitimate, scrupulous doctors would be embarrassed to use that phrase. The second clue is that Dr. Roberts seems to be a former contributor to Spy magazine. This is precisely the sort of hoax the editors of Spy would concoct. The third clue is that he uses just enough quasi-legitimate scientific theory and jargon to rope in many readers.
[I know “hoaxiness” isn’t a word. Neither was truthiness until Stephen Colbert coined it in 2006.]
I was particularly interested in the olive oil aspect of the Shangri-La Diet since olive oil is the predominant form of fat in the traditional healthy Mediterranean diet. I searched PubMed.gov for scientific clinical studies in overweight humans showing that olive oil suppresses appetite and leads to weight loss. I found none as of October 12, 2008. Note that extra light olive oil is refined oil and has less of the healthy phytonutrients found in extra virgin olive oil.
Dr. Roberts’ program, and its apparent success in some users, exemplifies the idea that losing excess weight is, in part, a matter of trial and error. For example, the Atkins diet may work great for you, but not your next-door neighbor, who lost with Shangri-La, which didn’t work for your mother-in-law. To some extent, weight-loss efforts are “an experiment of one.” What works for you is partially based on genetics (idiosyncratic metabolic processes), personal preferences, early childhood experiences, financial resources, preparedness for change, personality type, etc. However, two themes unify most people who have lost a significant amount of weight and kept it off long-term: 1) they don’t eat as much as in the past, and 2) they exercise more. Look for these when you search for effective weight-loss programs.
The aforementioned article brought to my attention by Evelyn Tribole suggests how olive oil and other unsaturated fats could curb hunger. Oleic acid, a prominent monounsaturated fatty acid in olive oil, is transformed into oleoylethanolamide (OEA) in the small intestine. OEA then activates a brain circuit that gives you a feeling of fullness, reducing appetite, and potentially promoting weight loss.
A 2007 article in the Journal of Molecular Medicine exposes a genetic variation that seems to prevent high fat consumption from contributing to overweight. Read about it at FuturePundit.com. The gene variant may be found in 10-15% of the U.S. population. Consumption of monounsaturated fats, as in olive and canola oil, almost seems to protect against overweight in people who carry this genetic variation. I’m talking about single nucleotide polymorphisms of the apolipoprotein A5 gene, specifically, -1131T>C. But you knew that, right? Nutritional genomics may eventually allow us to customize our food intake to work best with our personal genetic make-up.
A number of people, including Dr. Roberts, swear by the Shangri-La Diet. It works for them. I don’t think most of them are lying. Maybe they are in the subset of the population with the appropriate genetic variant.
It would be easy to design and execute an experiment on 100 subjects to test the efficacy of the Shangri-La Diet. Until that’s done - and it probably never will be - you could inexpensively try the Shangri-La “experiment of one” on yourself. From what I’ve read, you’ll know within the first week if you achieve the natural appetite suppression that substitutes for the willpower and discipline required by effective diets. As always, get your personal physician’s OK first.
If it is a hoax, I complement Dr. Roberts on his ingenuity. His book was a bestseller in 2006. For those he may have duped, it didn’t cost them much and probably caused no harm.
Steve Parker, M.D.
References:
Corella, Dolores, et al. APOA5 gene variation modulates the effects of dietary fat intake on body mass index and obesity risk in the Framingham Heart Study. Journal of Molecular Medicine, 85 (2007): 119-128.
Schwartz, Gary, et al. The Lipid Messenger OEA Links Dietary Fat to Satiety, Cell Metabolism, 8 (2008): 281-288. doi: 10.1016/j.cmet2008.08.005
