Malabsorption - RNY vs DS - Statistics

From a post by Diana Cox, one of our DS sisters: Let me summarize the important stuff:

DSers eat (by the calculated numbers) -- Calories: 3214 -- Protein g: 127.3 -- Fat g: 168.6

RNYers eat (by the calculated numbers) -- Calories: 2198 -- Protein g: 91.0 -- Fat g: 116.1

Preop MOs eat (by the calculated numbers) -- Calories: 2709 -- Protein g: 114.2 -- Fat g: 126.0

DSer's poop: Fecal fat g: 136.7 Stool wt g: 756 % fecal fat: 17.4

RNYer's poop: Fecal fat g: 44 Stool wt g: 270 % fecal fat: 14.9

Pre-op MO's poop: Fecal fat g: 10.3 Stool wt g: 208 % fecal fat: 5.0 *************** SO, for DSers: Fat in: 168.6 Fat out: 136.7 Amount malabsorbed: 81%

For Pre-op MOs: Fat in: 126.0 Fat out: 10.3 Amount malabsorbed: 8.2% -- EXACTLY 10X as much!!

As for RNYers: Fat in: 116.1 Fat out: 44 Amount malabsorbed: 38% --------------------------------------------------------

At the ASBS conference in July, Dr. Gagner published a short paper reporting just this information. It was freely available for a week or so, and then they took it down, but I saved the paper as a .pdf. Unfortunately, the way the table was constructed, it made it very hard to read and impossible to fix (when I delete one of the weird symbols, the number was removed with it!), so I summarized the data underneath:

DECREASED LIPID MALABSORPTION IN BOTH GASTRIC BYPASS AND BILIOPANCREATIC DIVERSION WITH DUODENAL SWITCH Michel Gagner, M.D., Tomasz Rogula, M.D., Gladys Strain, Ph.D., Rita Emerson, Lurent Biertho, M.D., Alfons Pomp, M.D., Department of Surgery, Weill College of Medicine of Cornell University, New York, NY.

Purpose: Bariatric surgical procedures for weight loss are hypothesized to produce weight loss both by restricting food intake and selectively producing malabsorption of fats.

Methods: In an attempt to quantitate fat and protein intake and caloric losses, we measured protein and fat intake and stool fat losses in 9 patients with a body mass index (BMI) 27.8 kg/m2, > 1 year after gastric bypass who were weight stable, 10 patients with a BMI of 26.5 kg/m2 who were weight stable > 1yr after biliopancreatic diversion with duodenal switch (BPD-DS), and 8 obese volunteers with a BMI of 41.2 kg/m2. Fasting lipid and fatty acid profiles were evaluated for fatty acid deficiency. Body composition was measured using bioelectric impedance.

Results: ............................BPD-DS..... GB........... Controls Calories calculated+ 3214  861 2198  307 2709  303 Calories reported+ 2680  1019 1586  362 2311  1013 Basal calories# 1529  260 1464  98 2086  357 % Body Fat # 28.4  8.3 33.0  6.6 43.9  7.8 *All NS Meals/day* 6.9  3.6 4.4  1.1 4.9  2.0 BPD-DS Stools/day 3.6  2.2 1.5  .8 1.9  0.6 &©
NS Protein,g calculated 127.3  30.0 91.0  18.2 114.2  22.2 #BPD-DS Protein,g reported 113.4  38.7 79.1  27.3 97.7  42.6 &GB
NS Fat,g. calculated 168.6  55.0 116.1  13.4 126.0  15.6 Fat, g reported 128.8  73.3 65.0  225.0 91.3  59.4 Fecal Fat, g 136.7  86 44  55.9 10.3  5.7 Stool Wt g. 756  378 270  269 208  79.4 % Fecal Fat* 17.4  4.8 14.9  4.8 5.0  2.7 Triene/tetraene ratio* .019  .022 .010  .003 .012  .006

Conclusions: All triene/tetraene ratios were 0.4, indicating no fatty acid deficiency. Those who underwent BDP-DS ate more calories (p 0.004), more fat (p 0.01), and more protein (p0.004) compared with those who underwent gastric bypass. They did not eat more frequently (p 0.10) or excrete a greater percentage of fat (p 0.29). They did excrete more fat (p 0.02) andhad larger (p 0.007) and more frequent (p 0.015) stools.

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Let me summarize the important stuff:

DSers eat (by the calculated numbers) -- Calories: 3214 -- Protein g: 127.3 -- Fat g: 168.6

RNYers eat (by the calculated numbers) -- Calories: 2198 -- Protein g: 91.0 -- Fat g: 116.1

Preop MOs eat (by the calculated numbers) -- Calories: 2709 -- Protein g: 114.2 -- Fat g: 126.0

DSer's poop: Fecal fat g: 136.7 Stool wt g: 756 % fecal fat: 17.4

RNYer's poop: Fecal fat g: 44 Stool wt g: 270 % fecal fat: 14.9

Pre-op MO's poop: Fecal fat g: 10.3 Stool wt g: 208 % fecal fat: 5.0 *************** SO, for DSers: Fat in: 168.6 Fat out: 136.7 Amount malabsorbed: 81%

For Pre-op MOs: Fat in: 126.0 Fat out: 10.3 Amount malabsorbed: 8.2% -- EXACTLY 10X as much!!

As for RNYers: Fat in: 116.1 Fat out: 44 Amount malabsorbed: 38%

He also said we had larger and more frequent stools.

All I can say is, WOOHOO! I don't mind pooping out 81% of the fat that I eat, even if it requires bigger poops!! Those statistics mean the following: the average DSer can eat over 1200 calories per day in fat FOR FREE! They can eat over 1500 cal from fat, and absorb only 288 calories; that's only 32 g of fat absorbed out of almost 170 consumed.

These numbers are for people over a year out with stable weight; I have also heard that in some cases, there is compensation long-term by growth of the common channel, increased intestinal villi that help with absorption, etc. Maybe so, but Dr. Hess' long term statistics (over 10 years out) show VERY stable weight for DSers, at about 78% of excess weight loss.

And yes, the insurance companies are LIARS -- as I think I said above, while the DS is CLEARLY better on average for those with a BMI over 50, it is also an appropriate surgery for just about anyone who needs WLS -- if you look at the DMHC appeal decisions, you will see the reviewers citing to references that say so, and they are almost always overturning denials by insurance companies who say there is no reason for people with a BMI under 50 to have the DS. And that's the primary reason for making this posting in the first place.

This is just amazing and very informative! Thanks so much for posting this.

Thanks Jeanie! I knew that paper was "coming out"!!!

Thanks so much for this information Jeanie.  It really confirms that I chose the correct surgery for me.

Sounds like a good surgery option.  I had the RNY and have had good results, but as I was reading the statistics, there was one that made me laugh--the bigger poop.   I already have trouble with getting my poop to flush as is--my plumbing can't seem to suck it down. Sally

that is way cool. i wish he'd run DS vs prox RNY vs a distal RNY like me (100cm common channel). We are thought to absorb only about 5% of our fat. I avoid low fat and fat free things like the plague, because they have sugar (taste nasty to me).

nice to see it in writing, at last!

I am a pre-op and curious....along with the malabsorbtion of fat what about the percentage of malabsorption with vitamins and essential minerals?  Is it significantly more with DS then with RNY? In doing my research, I find it significantly hard to find any long-term studies on DS (even the RNY studies are far and few between).  Please don't flame, I genuinely wish to know.

Actually, DSers have fewer vitamin deficiencies generally than RNYers. We usually don't have trouble with iron or B12. The fat soluble vitamins, esp. A and D, are watched by having labs drawn and if needed, you can supplement.  HTH Jeanie