Well blow me down! Another Paleo Study is Out!

As I mentioned in my last post, there's a new paleo diet comparison study out!  Long term ... two years!  Woo hoo!!  

Hold your horses.

One would think that before taking to social media to tout these things, folks like Robb Wolf, Stefani Ruper and Chris Kresser could hold their tongues long enough to at least obtain and skim the full text of the study they're going to cheer about to try and sell you stuff.  Long-term effects of a Palaeolithic-type diet in obese postmenopausal women: a 2-year randomized trial.  (link is to full text PDF).  

The Study  

This study was done on obese, post-menopausal women, with further characteristics shown in the table below, including some converted/estimated values.  The baseline energy expenditure and intakes are also shown.

Prescribed Diets

• Randomized assignment to diet
• Subjects blinded to assigned diet (IOW they weren't told what diet they were being put on by name)
• Both diets were ad libitum

• Support:

Each group took part in a total of 12 group sessions held by a trained study dietician (one dietician per diet) throughout the 24-month study period. The group sessions consistedof information on and cooking of the intervention diets, dietary effects on health, behavioral changes and group discussions. The subjects were given recipes and written instructions to facilitate the preparation of meals at home. Eight group sessions (four cooking classes and four follow-up sessions) were held during the first 6 months of the intervention.  Additional group meetings were held at 9, 12, 18 and 24 months.

• Diet assessment:  

4-day estimated self-reported food records conducted at baseline (2 4 days) and monthly until 6 months, thereafter at 9, 12, 18 and 24 months. Subjects were instructed to keep a record of all food items consumed over 4 consecutive days (three weekdays and one weekend day) and to describe and estimate the amount of food eaten by using coloured food-portion photographs representing known weights and household measuring utensils (for example, cup, spoon and standard weight of food items).

Actual Diets

values in ( ) are negative meaning falling short of target or differential

This is a rather big deal, because what is the purpose of this study, if not to compare the "long term" effects and effectiveness of two dietary regimes? It's not like they even came close either!   At the very least, the so-called "controversial" aspects of the diet should be adhered to so they can be tested.  

• The paleo diet is thought by some to be too high in protein.  The PD group didn't even hit 25% let alone the 30% protein they were supposed to reach.  (This was verified by a urine test).
• Critics of low fat diets say that 25-30% is too low in fat.  The NNR group barely lowered fat at 6 months, and actually increased it ever so slightly percentage-wise from baseline at 2 years.  So as has been seen in the past, so-called low fat diets generally don't alter this component much.  But they don't even meet the upper range of 30%!  (My values use the average 27.5%)
• Critics of high carb diets say that 55-60% of intake is too much.  The NNR group not only failed to meet this goal as any sort of a test of this claim, but they actually went the other way!    That's right.  In absolute terms the NNR group cut carbs  from baseline intake!  Their reduction in carbs, in absolute grams, was about 40% of the carb reduction of the PD group.

Values in ( ) are negative, Fiber and Evil Sucrose are in grams

• In terms of one of the only two emphasized food types, the NNR group does not appear to have paid attention to the fiber content of foods.  While they likely ate a bit more fibery foods, the absolute amount of fiber in their diet essentially flatlined.  

The above render this study effectively useless for the purposes for which it was undertaken.  How can you ascertain anything meaningful when you aren't even studying the intended treatment?    This is worse than studying a 100 mg daily dose of Drug A by administering a 75 mg equivalent dose of Drug B. 

We are told that the dietary assessments were done monthly for the first 6 months.   What is the point of continuing this study for two years, or even the six months, if after 1 month it was clear that neither group was even adhering to the macro recommendations?  Why, in those cooking classes and counseling sessions were they not counseled to, for example, eat more lean meat (for protein in the PD group) or eat more fruit (for carbs and fiber in the NNR group)?  Why?  What were the investigators thinking???

There Was Attrition

On the plus side, they only analyzed those that stuck with the diets instead of the awful intent-to-treat analysis.  Attrition was high, with 8/35 = 23% already lost at 6 months in the NNR group where only 22/35 = 63% completed.  For PD, it was a bit better losing only 1/35 = 3% at 6 months, while 27/35 = 77% completed.  Just how this attrition altered the results here is unknown.

The Results

There really are only two statistically significant results.  The "PD"-like diet outperforms the "NNR"-like diet at 6 months with weight loss of 6.5 kg (14.3 lbs) vs 2.6 kg (5.7 lbs) being statistically significant.  This translates to other weight-related parameters. Here are the body weight and measurement result plots.

Now, the PD still seems "ahead" at 2 years, but NS = Not Significant (statistically).  Just in case you're inclined to see this as still meaningful, I crunched a few things and shifted the NNR curves to match PD at 6 months.  Still NS, but over the long term, the PD trend vs. NNR was neither impressive nor better by trend.

The only other statistically meaningful difference of all that was measured, was the fasting triglyceride levels for the PD group. There was a drop from 108 to 74 mg/dL at 6 months, while the levels rose slightly for a net reduction from 108 to 88 mg/dL at 2 years. I would remind the audience that under 150 is "normal" despite what certain low carb advocates seem to believe.  Basically, the triglycerides were the ONLY characteristic that differed between the groups in the long term, and going from normal to a little lower normal is quite the bust here if you ask me. 

Some Basically Meaningless Banter

1. In absolute amounts, the NNR group reduced evil sugar intake by more than the paleo group. Both groups still certifiably not addicted at 2 years.
2. Both groups ended up decreasing absolute fiber intake slightly on their "healthier" diets. 
3. While the PD group increased O3s compared with NNR, they also increased O6s.
4. The PD group actually reduced saturated fats more than the NNR group on both an absolute level and as a percentage of total energy. The NNR group actually consumed about 1 teaspoon more of pure sat fat at 6 months, and around 1/2 tablespoon of more at 2 years. 
5. The most significant change seems to be in the MUFA consumption where the PD group was consuming about 1 tablespoon more MUFA than the NNR group at 6 months, but only about 1 teaspoon at 2 years. 
6. The PD group dropped sugar less and sat fat more and had lower triglycerides. Make of that what you will ;-)
7. Apparently the PD causes increased food intake amnesia with time as they under-reported intake more severely by the two year mark while gaining weight.  Either that, or as in the LC arm in Shai, we are to believe that they cut intake further during the latter phase yet regained some weight.

The "Paleo" Diet 

I will keep beating this drum.  Neither the "Paleo Diet" prescribed in this study, nor the one actually implementd, bears any resemblance to the popular implementation of the diet put forth currently by Wolf, Sanfilippo, Sisson, Gedgaudas, Jaminet or Kresser, to name a few, and especially not Dr. NBA Shanahan!  Not a one of them.   There is:

• NO dairy - not even a pat of Kerrygold let alone sticks, no parmesan, no mascarpone, no whipped cream, no ghee, no kefir, no yogurt.
• REDUCED sat fat (reduced more on an absolute level in the PD group than in the "mainstream" low fat NNR).  No tallow or lard.
• NO bacon or other fatty meats
• INCREASED MUFA and PUFA (including O6)
• CANOLA oil allowed and used
• NO coconut oil
• NO chocolate
• NO ketosis
• NO white rice
• NO kombucha
• NO bone broth
• NO tequila
• NO coconut and almond flour banana bread caveman one blender wonders
• .... you get the point.

This diet, either prescribed or implemented, is far different from that put forth by Cordain and Wolf in their fad diet books, however obsolete we are supposed to believe those books are.  

Therefore ....  If ANY of these gurus want to use this study in support of their advocacy of their increasingly nebulously defined and contradiction-riddled "paleo" diet, I'm going to call them on it, and I hope you will too.  It is DISHONEST.  Period.

To Be Continued ...

I had intended to do a "there are some meaningful takeaways" section here.  I had a snow day and some unexpected time here.   But alas, I've run out of steam and this has gotten long enough already.  There are some lessons to be learned from this for us postmenopausal women (and the people who love them ;-) ), and just women in general, vis a vis current diet trends and bogeymen.  I promise to follow up as soon as I can.

---

---

😇😈 Snark Time 😈😇

Minor edits were made Feb 1, 2019.  When originally posted in February of 2014, I led with this snarky bit about Robb Wolf's classy announcement of the new paleo study that will quiet the nay-sayers.  Still waiting on that major paper on paleo and Autoimmunity ....

---

The police chief in Reno and the powers that be at Specialty Health must be so proud to have such an endearing cockalorum as ambassador for their nothing-really-all-that-special-or-different CVD-risk-mitigation-through-low-sat-fat-diet-weight-loss-and-conventional-statin-and-other-meds program.   

This is surely the way to court critics and gain converts.