Interested in trying the alkaline diet but not sure which foods to avoid? This guide explores the top acidic foods to limit or eliminate, including meat, dairy, and processed treats. Learn how simple swaps in your diet can shift your pH and potentially improve your overall health.

Ready to be basic? We mean having a basic (alkaline) pH — the measurement of how acidic or alkaline something is.

Cue the alkaline diet that claims eating alkaline foods can alter your body’s pH. The science is iffy, but the claim is that an alkaline (basic) bod is more resilient from disease than an acidic one.

So what are the most acidic foods to avoid on an alkaline diet?

Acidic foods include:

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If you’re into tracking your body’s pH or actively following an alkaline diet, here’s the deal with acidic foods.

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The values of pH range from 0 to 14:

  • Acidic: 0.0–6.9
  • Neutral: 7.0
  • Alkaline (or basic): 7.1–14.0

Acidic foods fall into the acidic range of the pH scale and are different from acid-forming foods. Acidic foods have an acidic pH that doesn’t always leave acidity behind. Whereas acid-forming foods promote acidity in the body.

Foods also have different potential renal acid loads (aka PRALs). PRALS are based on acid excretion in your pee or the acid load your kidneys need to get rid of to keep a balanced pH.

Acid-forming foods tend to have high PRALs, which have been connected to Western diets high in animal protein. According to a 2019 meta-analysis, consuming a diet high in PRALs have been associated with high triglyceride levels and obesity.

Low PRALs are often related to plant-based diets full of fruits and veggies — even acidic ones like citrus fruits and tomatoes. A 2018 review found diets low in PRALs may be beneficial for kidney, heart, and bone health.

But can you actually change your pH?

In reality, what you eat can’t change your body’s blood pH — regardless of high or low PRALs. Your body naturally regulates your blood’s pH at 7.35 to 7.45. Certain foods can impact how much acid is in your urine, since that’s where uric acid exits the body.

Overall, your body stays slightly basic, but different body parts can have a completely different pH. Take your stomach for instance. In order to break down food, stomach acid needs to stay very acidic with a pH of 1.35 to 3.5.

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Still want to get alkaline? Here’s the breakdown on acidic foods that have high and low PRALs.

Soft drinks

Sipping on soda adds a bunch of phosphoric acid to your body, which causes an increased acid load. Phosphoric acid is often seen in Western diets and is highly absorbable.

Red and processed meats

Another high phosphorus food is red and processed meats. Phosphorus, plus the high protein content of these foods, equals an even higher dietary acid load. It’s not just red and processed meat either. Eating any animal protein, such as eggs and poultry, also creates an increased acid load.

Processed grains

Refined grains include foods like baked goods, fast food, and white bread. These noms all wind up contributing to a higher acid load. According to a 2014 article, adding fruits, vegetables, and other alkaline foods to these grains can help to reduce the dietary acid load.

Dairy products

When you eat dairy foods such as cheese, milk, and ice cream, you’re eating high amounts of phosphorus. Research also links dairy with other acid-forming compounds like sulfur-containing amino acids and chloride.

Acidic fruits

Although citrus fruits like oranges, lemons, limes, and grapefruit have a low pH level, they don’t create acid in your body when eaten.

On the other hand they’re considered reflexogenic foods, which can make acid reflux worse. For this reason, the National Institute of Health recommends avoiding or reducing citrus fruit intake if you have GERD (aka acid reflux).

Tomato products

Similar to citrus fruits, tomatoes and tomato products have a high acidity that can trigger acid reflux and make symptoms worse.

But eating raw tomatoes may be more tolerable compared to tomato products like ketchup, tomato sauce, and tomato paste. This is because raw tomatoes are slightly less acidic than their canned counterparts.

Acidic veggies

There are very few acidic vegetables (yes, tomatoes are a fruit!), but some veggies can become acidic depending on how they’re prepped. Pickled cucumbers or cabbage made into sauerkraut turn acidic, but in their natural form they stay alkaline.

Just because foods are acid-forming or just straight up acidic doesn’t mean they’re all bad.

But some acid-forming foods, like soft drinks, don’t provide any nutritional benefit. Research has found excess phosphoric acid from drinking tons of soda is linked to health issues like kidney problems and kidney stones, increased bone fracture risk, and prediabetes.

So if you’re worried about acid load health effects, it may be wise to cut down your soda intake or nix it all together.

Diets high in PRALs (think dairy and red meats) are also linked to heart and kidney disease. But that doesn’t mean these foods can’t have a place in a healthy diet if you balance your meals with fruits and veggies.

Foods like citrus fruits and tomatoes should only be avoided if you deal with GERD, otherwise keep them around. Since they’re low PRAL foods, they’re actually considered alkaline. According to a 2015 article, citrus fruits contain properties that are:

  • anti-inflammatory
  • antioxidative
  • cardiovascular protective
  • neuroprotective

The same goes for tomatoes that contain a beneficial antioxidant called lycopene. A 2020 article links lycopene to a decreased risk of:

  • cardiovascular disease (CVD)
  • obesity
  • type 2 diabetes
  • cancer
  • neurodegenerative disorders

It’s good to keep in mind that lycopene is relatively low in fresh tomatoes and significantly higher in cooked tomatoes. Combining cooked tomatoes with healthy fats helps your body absorb lycopene.

tl;dr: It’s all about balance

It’s fine to eat acid-producing foods like dairy and processed meats in moderation, maybe skip or limit the soda, and increase your intake of low PRAL fruits and veggies.

It’s generally believed this approach will keep ya healthy.

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Enough on what not to eat on an alkaline diet, the top alkaline foods to nosh on include:

While the claims of the alkaline diet are bold, many of these foods do have promising health benefits.

For example, the foundation of the Mediterranean diet is similar to the alkaline diet and limits red meat, cheese, and processed foods and is high in fruits and veggies. A 2018 article found following this type of eating pattern may help reduce the risk of developing chronic diseases like:

Wondering where your fave foods rank from acidic to alkaline? To make things simple, here’s where certain foods fall on the pH scale after being metabolized.

PSA: foods like limes, lemons, and tomatoes have an acidic pH, but are considered alkaline because of their low PRALs.

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When your diet is high in processed foods, red meat, and soda your acid load increases, which may cause health issues.

When eating in the name of health, limiting these acid-forming foods and increasing low PRAL foods like fruits and vegetables can be beneficial. But some acidic foods, such as citrus fruits and tomatoes, only need to be avoided if they trigger GERD symptoms.

There isn’t sufficient evidence that the alkaline diet can actually improve your health, but eating a balanced diet of acidic and alkaline foods does the body good. So before making any drastic changes to your diet, be sure to consult with a health professional to see if it’s the best switch for you.