A 2025 study published in Frontiers in Nutrition offers compelling evidence that dietary acid load (DAL) may play a critical role in metabolic health. In a randomized, controlled crossover trial, researchers compared a low-fat vegan diet and a Mediterranean diet over 16 weeks each. Both diets were nutrient-rich and calorie-matched, but only the vegan diet led to a clinically significant reduction in DAL, as well as greater improvements in weight loss, body fat percentage, and BMI.
What Is Dietary Acid Load (DAL)? DAL reflects the balance between acid-forming and alkaline-forming foods in your diet. A high DAL doesn’t alter blood pH (which your body tightly regulates), but it does increase the physiological burden on systems like the kidneys, bones, and muscles, especially in people with age-related or chronic health concerns. DAL is commonly measured using PRAL (Potential Renal Acid Load) and NEAP (Net Endogenous Acid Production) scores. Diets high in animal protein, refined grains, and processed foods tend to be acid-forming. In contrast, plant-based foods rich in potassium, magnesium, and fiber are more alkaline-forming.
Foods That Raise or Lower Dietary Acid Load
Acid-Forming Foods That Raise DAL:
- Red meat, poultry, eggs
- Cheese and other hard dairy
- Refined grains (white bread, pasta)
- Processed snack foods
- Sugary drinks and sodas
Alkaline-Forming Foods That Lower DAL:
- Leafy greens (spinach, kale, arugula)
- Cruciferous vegetables (broccoli, cauliflower)
- Root vegetables (beets, carrots, sweet potatoes)
- Legumes (lentils, chickpeas, black beans)
- Fruits (bananas, oranges, watermelon, berries)
- Whole grains (quinoa, oats)
- Nuts and seeds (almonds, chia)
A low-fat vegan diet naturally emphasizes many of these alkaline-forming foods, helping reduce DAL scores while also promoting satiety, energy, and micronutrient density.
What the Study Found Participants in the vegan diet group: Lost more weight, average 6.4 kg (14.1 lbs) vs. 4.1 kg (9.0 lbs) Had greater reductions in fat mass and BMI Experienced a statistically significant decrease in DAL (as measured by PRAL/NEAP)
Interestingly, these benefits occurred even though calorie intake was identical between the two diets, highlighting that what you eat may be just as important as how much.
Why This Matters Chronic high DAL has been linked to increased risk of bone loss, insulin resistance, type 2 diabetes, cardiovascular disease, and chronic kidney disease. Over time, a high-acid diet can lead to low-grade metabolic acidosis, which may stress your body’s buffering systems, even in people without kidney disease.
This study suggests that choosing more plant-based, alkalinizing foods may help reduce this burden, improve metabolic markers, and support overall health. It's not about blood pH, but about the metabolic cost of maintaining it. The low-fat vegan diet in this study significantly reduced dietary acid load and promoted more fat loss, without cutting calories more than the Mediterranean diet. For those exploring sustainable, food-based strategies for better health, this research underscores the power of plant-forward eating patterns.
If you're curious about practical steps to lower DAL:
- Try swapping meat for lentils or beans
- Add spinach or arugula to meals
- Choose whole fruits over processed snacks
- Replace soda with herbal teas or infused water
Over time, these small changes can ease metabolic strain and support long-term wellness.
Have you paid attention to dietary acid load before? How do you think food quality, not just calories, impacts energy and health? Would love to hear your experience.
Full study: https://www.frontiersin.org/articles/10.3389/fnut.2025.1634215/full