An alkaline diet centers on fruits, vegetables, nuts, and legumes while limiting meat, dairy, cheese, and most grains. The basic idea is to eat more foods that produce an alkaline effect in the body and fewer foods that produce acid. Most versions of the diet recommend that 60% to 80% of your plate come from alkaline-forming foods, with the remaining 20% to 40% from everything else.
What makes a food “alkaline” or “acidic” in this context has nothing to do with how it tastes. It refers to what happens after your body digests it. Lemons taste sour but leave behind alkaline byproducts. Bread tastes neutral but produces acid. Researchers measure this using something called PRAL (potential renal acid load), where negative scores mean alkaline and positive scores mean acid-forming.
Alkaline Foods to Build Your Diet Around
Fruits and vegetables are the foundation of the alkaline diet. Nearly all of them have negative PRAL scores, meaning they produce alkaline byproducts during digestion. The most potent options include spinach, kale, celery, cucumber, bell peppers, broccoli, and cauliflower. Root vegetables like beets, carrots, and turnips also score well. Among fruits, bananas, avocados, watermelon, and citrus fruits (despite their acidity on the tongue) are all strongly alkaline-forming.
Beyond produce, these foods fit comfortably into the diet:
- Nuts and seeds: almonds, chestnuts, flaxseeds, pumpkin seeds
- Legumes: lentils, navy beans, lima beans, soybeans
- Herbs and spices: ginger, garlic, turmeric, parsley, basil
- Plant milks: almond milk, coconut milk, soy milk
- Tofu and tempeh
Potassium-rich foods are especially emphasized. A study published in the American Journal of Clinical Nutrition found that older adults with higher potassium intake (from fruits and vegetables) had meaningfully more lean body mass. Those with the highest intake could expect roughly 1.6 kg more lean tissue than those eating half as much. So loading up on potassium-rich alkaline foods like bananas, leafy greens, and sweet potatoes may help preserve muscle as you age.
Acid-Forming Foods to Limit
Protein-rich animal foods and most grains sit on the acid-forming side. The strongest acid producers, measured per 100-gram serving, are hard and processed cheeses. Parmesan tops the list at +34.2, followed by processed cheese at +28.7 and cheddar at +26.4. Egg yolks score +23.4. These are the most acid-forming foods you can eat.
Meat falls in a moderate range. Corned beef scores +13.2, turkey +9.9, chicken +8.7, and lean beef +7.8. Fish like haddock comes in at +6.8. You don’t necessarily have to eliminate these entirely, but they should make up the smaller portion of your meals.
Grains are mildly to moderately acid-forming. Brown rice scores +12.5 and oats +10.7, while white bread is only +3.7 and white rice +1.7. Whole grain pasta lands around +7.3. This surprises many people since whole grains are considered healthy by most dietary standards, and they are. On an alkaline diet, you’d simply pair them with generous amounts of vegetables to offset their acid load.
Other acid-forming items include alcohol, coffee, refined sugar, and most processed foods.
Neutral Foods: Fats, Starches, and Sugars
Some foods land near a PRAL score of zero, meaning they don’t push your body significantly in either direction. Natural fats like olive oil and butter fall into this category. So do certain starches like corn and sweet potatoes, along with simple sugars. Most alkaline diet plans suggest using these in moderation rather than making them the center of your meals. Olive oil as a cooking fat or salad dressing is perfectly fine. It just doesn’t “count” toward your alkaline intake.
What a Day of Eating Looks Like
There is no single official alkaline diet, which can make getting started confusing. The most common guideline is the 80/20 rule: aim for roughly 80% of your food from alkaline sources and 20% from acid-forming or neutral sources. A more relaxed version uses a 60/40 split, which is easier to maintain long-term and still shifts your overall dietary pattern significantly.
A practical day might look like this: a smoothie with spinach, banana, almond milk, and flaxseeds for breakfast. A large salad with mixed greens, cucumber, avocado, chickpeas, and olive oil dressing for lunch. A dinner of roasted vegetables and lentils with a small portion of grilled chicken or fish. Snacks could include raw almonds, celery with hummus, or fresh fruit.
The pattern is consistent: vegetables take up most of the plate, plant proteins appear frequently, and animal protein becomes a side dish rather than the main event. If you eat grains, pair them with a larger volume of vegetables. If you eat cheese, keep portions small and infrequent.
What the Diet Actually Does in Your Body
One common misconception is that eating alkaline foods changes your blood pH. It doesn’t. Your blood pH is tightly regulated between 7.35 and 7.45, and your body maintains that range regardless of what you eat. What changes is your urine pH. A high-protein, low-vegetable diet produces very little change in blood chemistry but significant changes in urinary chemistry. Your kidneys handle the balancing act, excreting more acid when you eat more acid-forming foods.
This is where the diet may matter most for certain health conditions. A typical modern diet produces 50 to 100 milliequivalents of acid per day. Your kidneys can excrete roughly 45 milliequivalents daily using phosphate as a buffer. For healthy people, this works fine. But for people with chronic kidney disease, that excretion capacity drops below 20, meaning the daily acid burden accumulates faster than the body can clear it. Research from clinical practice has shown that reducing dietary acid load by eating more fruits and vegetables and less animal protein can slow the progression of kidney disease, and occasionally even improve function.
Bone and Muscle Health Claims
The alkaline diet is frequently marketed as a way to prevent osteoporosis. The theory is that acid-forming diets force your body to pull calcium from bones to neutralize the acid, gradually weakening them. The evidence here is mixed. A systematic review and meta-analysis found no strong support for the idea that an alkaline diet specifically protects bones through acid-base mechanisms. Several randomized controlled trials have shown that high-protein (acid-producing) diets don’t significantly affect bone density or bone turnover markers.
That said, fruits and vegetables clearly benefit bone health. An umbrella review found that adequate intake of vegetables, fruits, and key micronutrients reduces osteoporosis risk. The benefit likely comes from the vitamins, minerals, and other compounds in these foods rather than from their effect on pH. So the diet’s emphasis on produce is genuinely good for bones, just not necessarily for the reason proponents claim.
The muscle preservation angle has slightly better footing. The potassium salts found abundantly in fruits and vegetables appear to counteract the muscle-wasting effects of mild metabolic acidosis that occurs with aging. In older adults, higher potassium intake correlates with greater lean body mass, though the relationship hasn’t been proven to hold over time in long-term studies.
Making It Sustainable
The biggest practical challenge with the alkaline diet is that it restricts several nutrient-dense food groups. Dairy is the most concentrated dietary source of calcium. Meat and eggs provide complete protein and iron. Whole grains deliver fiber and B vitamins. Cutting these sharply means you need to be intentional about getting those nutrients from plant sources: fortified plant milks for calcium, legumes and tofu for protein, leafy greens for iron, and nuts and seeds for trace minerals.
Starting with the 60/40 approach is more realistic than jumping to 80/20. Focus first on adding more vegetables to every meal rather than eliminating foods. A plate that’s two-thirds vegetables and one-third grains or protein is already a significant shift for most people. Over time, you can experiment with higher alkaline ratios and see how you feel. The core of the diet, eating far more fruits and vegetables than the average person, aligns with virtually every evidence-based dietary guideline, regardless of what you think about pH.