How does your alkaline diet work?


  • Discussion
  •  Twitter Foodie #47

    I use the PRAL calculation to provide scores for thousands of food items from the USDA database. Then I present groups of foods in various lists throughout Because people who want an alkaline diet must avoid spurious lists of foods based on obsolete ash-based calculations. But the Internet (and many books) is overwhelmed by millions of pages that continue to promote incorrect alkaline food data.

    So this post is a collection of questions from people who want more information about how PRAL-based alkaline diet works.

    Original post continues…

    I’ve been trying to find how an alkaline diet works and I found a tweet about pH Spectrum diet at

    It looks much easier than your alkaline diet charts. Is this better than PRAL?

    PRAL Alkaline/Acid Chart Layout
    PRAL Alkaline/Acid Chart Layout
  •  Keith Taylor #401
    Ŧallars: Ŧ 1,142.29

    Sorry for the delay in replying.

    You are right that the diet looks easier. But, it isn’t an alkaline diet. That chart, and similar looking graphics, are all over the Internet, but they are fundamentally flawed.

    They are all based on a technique that was investigated many years ago. It involves incinerating food, then measuring the pH of the resulting ash. The data is still included in the USDA databases that I use. The difference is, I ignore it because it is meaningless as far as diets are concerned. In fact, it is worse than that – it is misleading.

    Coincidentally, there are many healthy foods in my PRAL tables that also produce alkaline ash. But this is not the basis for a healthy diet.

    PRAL estimates the effect of food on the kidneys. The alkaline affect happens due to how our bodies digest the nutrients that form the PRAL calculation. There are other factors that affect acid load at the kidneys, but those are the most significant food related items.

    This does not mean to say that you cannot eat healthily on an ash-based diet. However, you have no accurate way of planning or assessing your food intake if you rely on ash calculations.

    With PRAL, you can assess your total diet, and you can also use PRAL tables to improve your alkaline diet. By changing some of your food to a lower PRAL value, you will always reduce the acid load on your kidneys.

    Remember though, the objective is not to minimize your PRAL score. A healthy diet must include up to 25% acid forming foods, but the overall balance must always be alkaline. Your best approach is to achieve this with a wide range of different fruits and vegetables.

    I hope this makes it clear. If not, please log-in and ask further questions.

    If anyone has trouble logging in, you can ask questions, and share opinions via the red Help button. This will add a ticket to the Foodary Helpdesk, but please note that I give priority to forum discussions, and helpdesk responses may take several days.

  •  Foodary Helpdesk #403
    Ŧallars: Ŧ -11.05

    Your chart for alkaline baked foods shows (Leavening agents, baking soda) as 0.00 are you sure that’s right? I find it very Alkaline.

    Please explain.

    •  Keith Taylor #405
      Ŧallars: Ŧ 1,142.29

      Hi gwsheetmetal and thanks for your question about PRAL.

      I hope you can see from that PRAL is not directly associated with measuring pH. As I suggested above, you can reduce the average PRAL of your total food intake, and this should increase the pH of your urine – i.e. make it more alkaline.

      This happens due to the way you digest food, and is the result of a complex series of organic reactions. As I said, PRAL is an estimate of what will happen at your kidneys based on normal food digestion. It is designed to measure food intake.

      However, acid load at the kidneys (renal acid load) can also be changed by many other factors. Chemicals from food additives, supplements, medicines, and other sources can affect renal acid load. These chemicals do not occur in food in abundance, so they are ignored from the PRAL calculation.

      This is done to make PRAL useful for food analysis. There is another calculation for estimating renal acid load, called NEAP. This is often deemed to be more accurate, as it includes bicarbonates in the calculation. That might be true in the lab, but it is rarely relevant in the kitchen.

      In a healthy diet, baking soda should not form a significant part of your total food intake. Therefore, PRAL is accurate enough to guide us towards healthier eating. There is no doubt that bicarbonates in baking soda and other chemicals will reduce the acid load on your kidneys. However, this is not relevant to healthy diet.

      If you have a medical condition where alkalizing urine is important, such as certain kidney stones, then bicarbonate supplementation usually helps. Sodium bicarbonate (baking soda), potassium bicarbonate, and potassium citrate are all used medically for this purpose. However, they are usually irrelevant to PRAL calculations, and they are not food.

      The whole point of PRAL is to use it as a guide towards healthy diet. However, it is not a target in itself. False alkalization using chemicals will not improve your health. Alkaline foods balanced with less acid foods is the only way to achieve good health. In the same way, you should ignore any processed supplements and drinks that claim to be healthy just because they are alkaline.

      Alkalizing is a product of a healthy diet. Alkalizing is not a goal in it’s own right.

  •  Keith Taylor #459
    Ŧallars: Ŧ 1,142.29

    I’ve just had a further thought about PRAL scores in different circumstances. Prompted by a comment on my alcoholic alkaline drinks page.

    That comment, and my response, are about the physical pH measurement of drinks, compared to the effects of drinks on alkalizing urine after digestion.
    I wonder if there are some illnesses where the physical pH matters? Please let me know your thoughts.

  •  Foodary Feedback #691

    Acid-Alkaline Nut and Seed Products Food Chart
    I appreciate all your hard and detailed work for a great cause, but I don’t understand the meaning of the numbers, especially those with the negative signs.

    Very confusing, so the figures in this nuts chart was minimally helpful. I did find out that my beloved cashews are quite acidic 😔 but the numbers mean nothing.

    I was looking for an explanation or for captions, like those you’d find on two adjacent sides of a graph. The K cals column is confusing too.

    [Posted via Feedback Form. But note that form is designed for non-urgent suggestions about improving Foodary information. So if you need personal replies you should Start a new Healthy Eating Forum Topic.]

    •  Keith Taylor #693
      Ŧallars: Ŧ 1,142.29

      I also realized the importance of understanding PRAL table layouts. So I started each chart in that series with:

      Please see my explanation of the values for this acid-alkaline Nut and Seed Products food chart, and related charts, in my Basic Acid Alkaline Food Chart Introduction.

      Hopefully, that answers all your questions. But I understand that adding links to the table headings makes finding the information easier. So I started doing that in the second series of PRAL tables.

      Now, based on this type of feedback, I can see that I need to completely overhaul all the PRAL alkaline diet tables. So once I work out a better structure, I will do that.

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  •  Foodary Feedback #731

    Alkaline Food Lists Explanation
    Your PRAL score has no given range so it’s essentially useless!

    [Posted via Feedback Form. But note that form is designed for non-urgent suggestions about improving Foodary information. So if you need personal replies you should Start a new Healthy Eating Forum Topic.]

    •  Keith Taylor #736
      Ŧallars: Ŧ 1,142.29

      I don’t understand why having a range is helpful when planning a PRAL-based alkaline diet. More importantly, you don’t say if you need a range for your total PRAL target. Or a range of PRAL scores for individual food items.

      Typically, you would start your PRAL planning by measuring your historic score. So I find the easiest way to do this is to look at my food purchases. But others find that measuring each meal gives better information for them.

      Whichever way you do it, you end up with an average daily PRAL score. In the page you refer to, I explain that the average PRAL value for a 2000 calorie diet is -20. But you always want a more negative score than that. So for planning purposes, you might target a PRAL range of -20 to -50 per day. Then you can adjust your range as you progress with your healthier diet.

      On the other hand, you might be referring to a range of PRAL values for individual food items. In which case, that information is already included in each chart on the page you are asking about. Because all those charts start with the most alkaline PRAL score first. Then items are listed in PRAL order, ending with the most acidic. So all you have to do is click the arrow on the PRAL Score heading to reverse the sort order.

      For example on the Alkaline Vegetables List, it starts with raw spinach at the top with a PRAL score of -51 for a 435-gram serving. Then when you click the arrow next to the PRAL Score heading, the chart switches to most acidic at the top. Alternatively, you can scroll all the way to the bottom of the list. In either case, the most acidic vegetable is boiled frozen green peas with a PRAL score of 3 for a 128-gram serving. So the PRAL range for vegetables (alkaline to acid) is -51 to 3.

      Remember that these tables are just a selection of the most common foods. So in my example, you might find vegetables that are outside that range. Also, from your personal point of view, you have to adjust the PRAL score for your meals according to serving size.

      TL;DR – Forget about ranges and focus on healthier eating. All you need to do today is eat a more alkaline PRAL total than you did yesterday.

  •  N. Patricia #627

    PRAL Chart formats

    I have just discovered you websites, and the information is personally very useful, indeed invaluable and timely due to a number of serious health issues. THANK YOU.

    I have a few suggestion to improve three of the Charts, and will submit my observations/comments separately

    N. Patricia

    [sent via feedback form – additional responses below]

    Re: Breakfast Cereals Chart

    I have noted that:-

    1) The column headed “Very Alkaline” has both positive and negative entries.

    2) Various positive entries in the “Very Alkaline” column seem to be too low to indicate “very alkaline”

    Re: Vegetables and Vegetable Food Products Chart

    Various positive entries in the “Very Alkaline ” column seem to be too low to indicate “very alkaline”. It might be that I do not fully understand the concept. Please clarify

    Re: Baked Products

    Here also, various entries in the Very Alkaline” column seem too low to indicate “very alkaline”

  •  Keith Taylor #648
    Ŧallars: Ŧ 1,142.29

    I’m very sorry about the formatting issues on the pages you mention. As I’ve noted elsewhere, this is a transitional problem that I’m aware of. But unfortunately, I cannot find a quick fix. So, I’m going to rewrite the tables that you mention plus all the others in that series.

    At the same time, I want to make my PRAL food charts easier to use if I can. So if you have any suggestions for the type of layout and information that is best for you, I would love to know.

    In the meantime, please note that the PRAL values shown are correct. But, they are not aligned in columns. However, those columns never had any real meaning, and I dropped them in subsequent PRAL charts.

    In any event, it would help me enormously to learn how individuals are using my PRAL food charts in practice. That way, I can get insight that might help me improve future layouts.

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