This is hopefully not being intrusive to LeeAnn … for I am attempting to give an answer on another consultants page and on a topic about which they know far more than I … but, hopefully, LeeAnn will not think ill of me for doing so. While I have minimal expertise in the area, it is one on which I have formed a number of [probably wrong] views over my 40 years in the kidney business. I just couldnt resist!
Premise:
I want my patients - as much as is possible - to eat well!
I worry that too much ‘eat this, dont eat that’ instruction bedevils CKD and CKD patients. We put the fear of God into our patients over diet - and the consequences of too much or too little of this and that … Na+, K+, PO4, Ca++ and protein being chief of these … when, for most, and within reason and commonsense, I am still not sure whether we may do more harm through rules, restriction and limited diets than we do good.
Better dialysis … here I go again, I know … not dietary draconianism, should be the way forward.
No dialysis patient should have to eat other than a normal balanced diet, well protein’d, well everything’d … and yet they must!
Why? … because, in brief, we fail them.
OK … that’s the heresy (to a point) … but let me explain.
Protein:
I have always been of the view that as regards protein, complex animal proteins are more of a ‘renal’ issue (and experimental data supports this view) than are the less complex vegetable proteins – and in this regard, where protein restriction is advised, I try to down-size animal and up-size fish and vegetable-sourced protein – ie: I tell me patients they can eat fish and veggies more often in a week but less (though not nil) meat each week!
Protein restriction as a mechanism to ‘lessen the metabolite load’ – especially urea and other nitrogenous waste levels – has come and gone as a ‘fashion’ over the last 50 years. Giordano and Giovannetti first seriously influenced thinking about protein restriction before the days of maintenance dialysis (the 50’s) but then came dialysis and it was viewed as preferable to have a well-nourished patient, unwasted by severe protein restriction, entering dialysis a little sooner but in better health than trying to delay dialysis (in my view spuriously) through protein restriction and then having a muscle-wasted scarecrow present a few weeks/months later.
In the last 50 years, dietary protein restriction has come and gone, then come, then gone again … its fashion waxing and waning. I, for one, think it largely unhelpful to protein restrict – except perhaps to limits phosphate intake …and again, as pointed out by others already here, the phosphate content of protein foods varies too. I have been in the ‘I don’t restrict protein camp’ – perhaps with the caveat that I also don’t advise a protein dietary glut either … rather, I upsize fish and veggie-based protein and downsize meat-derived protein while allowing, not barring, both. We need somewhere around 0.75gm/kg/day protein to sustain a nice protein balance. Most/many western diets (perhaps above all the US diet) contains much more protein than this. So … rather than limiting protein, I like to ‘dial’ a protein intake that gives plenty for a gentle positive balance while avoiding its over-ingestion.
One problem with protein is that it is also a key source of phosphate.
Here comes the major heresy …
Phosphate:
I think we have over-cooked the dangers of phosphate (and potassium falls into the same boat) … driven NOT by the (wrongly) perceived dietary naughtiness (some use here a word I abhor … non-compliance) on the part of our patients but by inadequacy of the dialysis inadequacy programs we deliver!
So … what am I saying here? I am saying that it is NOT our patients’ failure us by failing to adhere to often impractical (and commonly costly) dietary restrictions that causes all the trouble… it is us failing our patients by delivering inadequate dialysis. We are at fault, not the diet, not the patient, not the dietitian … but the dialysis prescription we prescribe!
Longer, more frequent dialysis has taught us much. It has taught us that our patients can eat what they like! Clearly, I mean here a nutritious diet (not fast foods, not fatty crap, not prepared soft drinks - Coke and its friends are phosphate soups) … but good food, varied food, fresh and of any type you like should be possible for all dialysis patients, if only we provided them with good dialysis!
I have yet to see one of our NHD patients in phosphate excess … in potassium excess … in urea or nitrogen excess … and they eat like they should – normally.
And, they take no binders either.
Phosphate excess (once dialysis starts) should be a thing of the past. It isn’t … but that’s because of our (medical) failing, not your (patient) failing.
Our collective struggle with binders, sevelamer, lanthanum (have you ever seen the ‘rare earth’ abdominal xrays that go with lanthanum?) … etc etc … and the difficulties our patients have with taking them … this struggle is the result of poor dialysis.
Potassium:
The same applies (pretty much the same) to potassium as it does to phosphate … though here, some medications can be also contributory to rising K+ levels. I don’t blanche, I must say, at K+ up to 6 or so. Certainly dialysis patients develop some degree of apparent ‘tolerance’ of not only a potassium of 6+ but also of the rapid serum shifts that occur in potassium during dialysis. Why? Well … potassium is a largely intra-cellular beast! Though we can alter (sometimes markedly) the serum potassium during dialysis, the intracellular potassium is much less affected. We sometime see this when, on return to the ward after dialysis, an inpatient whose potassium is 2.8 post dialysis when it was 6.5 prior, is given potassium by an ill-advised junior doctor to treat the ‘low’ potassium level when, if he/she had just waited 30 minutes or so and repeated the level, the potassium would have equilibrated with the cellular level and bounced to 4!
I am not trying to be blasé about potassium … just I don’t worry about it quite so obsessively as some might.
Furthermore, with better dialysis, potassium issues disappear. Indeed we have had, on occasions, to ADD potassium to the diet and/or medication lists of patents on longer and more frequent dialysis until dietary freedom ‘catches up’ with the better dialysis and restrictions previously ingrained are slowly lost as the diet returns to normal.
What matters most:
Weight management to ‘ideal’ or target weight … and this is nowhere more important than in the diabetic dialysis patient … and exercise.
These are easy to say - but never easy to achieve … especially for weight control in the overweight patients.
These, however, should be the subject of a different discussion for LeeAnn to supervise.
Summary
I am not trying to be dismissive of diet here - it matters for almost all dialysis patients … for almost all dialysis patients are being underdialysed and therefore must adhere to strict limitations on the food they eat to compensate for our failure to better manage them.
A restricted diet is inescapabale, inevitable, and essential for almost all dialysis patients - short of the lucky few who seek (and find) good dialysis.
But … a dialysis patient should be able to eat what he/she wants, without fear of over-this or under-that. At the moment, sadly, only those who can access enough evenly-spaced hours of dialysis a week can achieve that.
For the rest - it is (sadly again) over to the pills, to the dietitian … and to sticks and threats.
There is one caveat to this. That is the (usually short) window of CKD5 prior to dialysis (assuming that that dialysis is good dialysis) when renal excretory control has been lost but dialysis control has not begun. That is a small window. It is rarely, in my experience, a long-enough time for major mischief to ensue - and it can be (and is) managed by medication and some dietary measures. But, once the eGFR falls <10 and dialysis is imminent or is started, the dietary measures of this brief period should be able to be relaxed as dialysis (good dialysis) takes over.
That we rarely reach that balance point is our failing … not yours.
I know everyone thinks these are “healthy.” But that’s not necessarily the case. OTOH, I should warn you that I have ZERO training in nutrition. Strictly an amateur who reads a lot & is trying not to get type 2 diabetes like my dad has.