DS Math

Discussion in 'Duodenal Switch' started by DianaCox, Feb 16, 2014.


    DianaCox Bad Cop

    Reposting my article from DSFacts.com:

    This is to explain the "DS Math" for those wondering how DSers can eat 3000+ calories per day and not gain weight. Some people also seem to have difficulty understanding why our arteries aren't clogging up, since most of us eat about 50% of our calories as fat. For those of you who are interested, this is how the math works.

    Note that in this DS math explanation, while the 80% fat malabsorption had been documented by a study by Gagner et al. [68], the 40% malabsorption figure I use for both complex carbohydrates and protein malabsorption are only estimates, and are probably quite a bit more variable person-to-person than the fat malabsorption, because there is SOME digestion and absorption of protein and complex carbs in the small intestine as the result of acid digestion by the stomach and enzymes secreted in the mouth and the jejunum and ilium, together with the much more variable length of the alimentary tract between patients, whereas fat digestion and absorption essentially only occurs in the common channel. The 40% figure comes from conservatively averaging a number of figures -- guesstimates, really -- that I have read and heard from surgeons over the years. These numbers are rough estimates for the purpose of explaining generally how the DS works - these numbers are NOT intended for you to use with any hope of accuracy. And not only will each individual vary in their malabsorption from another person, but each individual's malabsorption will vary over time. This is for illustrative purposes only!

    I (and many if not most DS post-ops over 2 years out) eat about 3000 cal/day most days. But we don't absorb that much, of course. This is the "magic" and the pleasure of how the DS works, and why it works. The DS math of malabsorption looks something like this:

    I always get about 100 g of protein/day (I have never had protein shake -- since surgery; I have eaten all my protein as food). 100 g of protein x 4 cal/g = 400 cal eaten; x 0.6 (60% of protein absorbed) = 240 cal from protein absorbed.

    Since I eat at least 50% of my calories as fat (full fat mayo to my heart's content; butter with my seafood and veggies; full fat salad dressing, and lots of it, with my salads and veggie dips; nice marbled meats including steak, bacon and crispy chicken skin), let's call it 1530 calories which equals 170 g of fat (fat is 9 cal/g) to make the math easier. But I absorb only 20% of the fat I eat, for only 306 cal from fat absorbed.

    So, fat + protein eaten = 1930 calories of the 3000 I eat per day. That leaves 1070 cal or 267.5 g of carbs (4 cal/g). But I only absorb about 60% of complex carbs. I have to account for sugar first, because I do absorb 100% of sugars -- I would guesstimate that I eat about 50 g of sugar/day x 4 cal/g for 200 calories from sugar absorbed; of the remaining 870 calories of complex carbs x 0.6 (60% absorbed) = 522 cal from complex carbs absorbed.

    Here is the DS math. My ABSORBED calories from 3000 ingested calories (eating 100 g of protein, about 50% fat and the rest carbs) is:

    240 calories from protein
    306 calories from fat
    200 calories from sugars
    522 calories from complex carbs
    1268 calories absorbed per day from eating 3000 calories

    And that is why I (and other DSers) can eat like that, not exercise, and still be either maintaining or losing weight. It doesn't suck!

    (Note: I didn't include alcohol, which is FULLY absorbed and 7 cal/gram - and is usually accompanied by more fully absorbed calories. You are warned!)

    To be clear, I am NOT advocating not exercising! Everyone needs exercise for cardiovascular health, bone health, looking toned, etc. My point is, exercise for losing or maintaining weight loss isn't as necessary for most DSers.

    As for arteries clogging from all that fat -- what doesn't get absorbed doesn't get to my arteries, of course! My total cholesterol is 167, my HDLs are 53, and my LDLs are 95. My triglycerides are 95. All of which numbers are EXCELLENT -- my doctor wishes her levels were that good. My CRP (an indicator of inflammation and thus cardiovascular risk, especially in women), which was a dangerous 10 times normal pre-op, and which was not helped much by statins, is now completely normal with NO statins. My cardiologist released me -- there is no need to see him anymore!

    Note that contrary to unfounded accusations, I don't eat huge amounts of food at a time (nor do most of us) -- I do eat smaller, higher calorie meals (full of yummy fat!), and I eat 4-6 times/day. I didn't binge pre-op, and I don't binge now. I usually get at least a snack if not an entire second meal out of a restaurant meal, which for me is generally sharing a couple of appetizers with my husband, sometimes a piece or two of bread with LOTS of butter, an entree of my own, and sharing a dessert, along with a drink (Mai Tai!). I usually take home some of one of the appetizers, and half of my main course, and finish it off before bed or for breakfast the next day.

    I didn't have a major sweet tooth pre-op, but I eat even fewer sweets now -- the DS changes metabolism to correct insulin resistance, and after 2-4 bites of something sweet, I am generally done. I am satisfied with fewer sweets than I was pre-op -- sweets taste DELICIOUS for a couple of bites, and then taste overly sweet. I get both the pleasure of having sweets with no repercussions, and no fear of overindulgence. Sometimes, when I feel inclined to indulge but find myself physically not wanting more, this is almost amusingly annoying. No willpower needed!

    By the way, based on studies on people with short bowel syndrome, intestinal adaptation is generally complete by about 2 years out. The statistics of weight loss maintenance over 10-15 years with the DS supports the theory that the same is true for DSers -- if there was continued adaptation of the intestines after two years, there would likely be significant and ongoing weight gain in long term DSers, which there generally isn't. But slowing down as we age probably DOES put us at risk - just like anyone else.

    Whit Well-Known Member

    Thanks Diana this is very informative. I have a DS Math Excel sheet (from the OH FB group) that does all of the work for me it's very helpful. I would post for others but the site will not let me.
    Will2014 likes this.

    DianaCox Bad Cop

    I cannot emphasize this enough - tracking your intake using "DS Math" is pointless. IT IS NOT A TOOL THAT MEANS ANYTHING - IT IS A HYPOTHETICAL EXAMPLE TO ILLUSTRATE GENERALLY HOW OUR MALABSORPTION WORKS! Any particular person, at any particular point in their journey, is going to malabsorb wildly different amounts of the various nutrients.

    Count your protein, and then check your labs - if you need more protein, eat more. If your protein labs are good but you are gaining (and it's not related to carb intake), eat less protein. Eat as much fat as your body will tolerate - it fills you and isn't likely to cause problems, whether you are absorbing only 10% or 35%.

    But tracking using the numbers above? I'm sorry, that is a waste of time, and very misleading.
    DSRIGGS, Will2014, joyann1968 and 3 others like this.

    ProteinSnob Well-Known Member

    I hadn't heard that before, @DianaCoxDianaCox . Thank you for clarifying.
    BigRed1 and Will2014 like this.

    galaxygrrl Well-Known Member

    This is one of the most helpful posts I have read in 2 weeks of intense research! Thank you
    Ede Murdoch, Will2014 and JuliaDS like this.

    Larra Well-Known Member

    Hey @galaxygrrl@galaxygrrl ! Great to see you found your way here. Keep on reading, there is already so much information posted on this website, and of course ask any questions you still may have. Also, since you are planning on going to Mexicali and Dr. Esquerra, you will find a fair number of his patients here, and I think you'll see they are very happy with the care they received there.

    On the other site, you mentioned you were considering both DS and SADI, aka loop DS aka SIPS. Please, please read the posts here on this topic, and understand that the SADI is not the same as the DS, is not a standard of care operation in the USA, is still experimental (despite the fact that a few surgeons are pushing it), and that all the documentation showing the excellent long term results of the DS for percentage excess weight loss, for maintaining that weight loss, and for resolution of all major comorbidities applies only to the classic DS with 2 anastomoses and NOT to the SADI. Perhaps some clinical trials will someday show how well or how poorly it works compared to the DS, but at this point we don't have that knowledge, and the only positive thing I can say about it is that it is almost certainly better than gastric bypass, but that's not good enough.
    TheWeightIsOver, Will2014 and DSRIGGS like this.

    Mystrys Walk in Beauty,Walk in Integrity

    Love this post...plus it kept me from asking the really dumb question of whether we can actually eat too much....especially early out from surgery. Didn't seem to me that 12-1500 calories would be too much,even a few months out but I questioned it due to a slow down of weight loss at only 7 weeks out.
    I love this place!!:inlove:

    DSRIGGS Yes, that is chocolate covered bacon

    Great advice. On Dr K's group this morning there was a lady who said she absorbed 19% fat and it made me think of this post. My comment was basically that those were rough numbers and that we all absorb differently so don't take them to seriously. I believe this young lady is also high fat determined because she says her cholesterol is dangerously low. I have tried to tell her that you can't make your DS absorb more fat than it is capable of absorbing so I am not sure how much one can actually influence their lipid panel by adding more fat to the diet.....and if cholesterol is really low (I have asked her a couple times but she hasn't told me her numbers).

    One thing that I have learned from this journey is that maybe I need to be taking my A, D, E & K differently. Typically when I get up in the morning I make a cup of coffee and swallow my A, E, D, K1, K2, Multi, probiotic, Copper and PPI. Then I make my eggs and PB&J toast, so 10-15 minutes after ingesting the vites I am eating a meal that has fat in it. Dr K suggests not taking the water miscible vitamins with any fat so maybe I need to take the vitamins and hour after I eat?
    Mystrys likes this.

    Annabelle Active Member

    Wow awesome post. Very informative

    DSRIGGS Yes, that is chocolate covered bacon

    Welcome Annabelle. You will find that this place is a wealth of knowledge and huge help to those adjusting to the DS lifestyle.

    DSRIGGS Yes, that is chocolate covered bacon

    Thanks but I know numerous people who have tried the patches and they don't work for a DS'r. I get vitamin A & D injections.

    DianaCox Bad Cop

    @Munchkin@Munchkin - Can you provide the information from the other website(s)?

    Bottom line - the patches don't work very well or at all for most people.

    southernlady Administrator Staff Member

    @TheWeightIsOver@TheWeightIsOver They HAD a patch group on FB but the results were dismal so they disbanded it.

    Sounds like a great idea but it's not a long term viable option, esp for DS'ers.

    Munchkin Full of Fairy Dust

    It doesn't come up on FB anymore. Quite a few people tried it.

    k9ophile Well-Known Member

    Just my two cents worth: I was on an antidepressant patch. No matter how I cleaned the area, it would not stay on. I know patches have some use, but I will avoid them if at all possible. If I can't keep them attached they aren't doing any good.

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