Balanced Alkaline Diet: The Plate Rule and PRAL

---

What “balanced” means

Balanced is not a diet. It is a distribution: every food group shows up, and none dominates. The German Nutrition Society (DGE) sums this up in ten rules and a food circle. The Harvard plate rule turns it into a picture you can apply to every meal.

The plate rule:

• Half the plate: vegetables, salad, fruit. The more colorful, the more different vitamins and phytochemicals you get. Potatoes don’t count here.
• One quarter: whole grains, potatoes, rice, pasta. Whole grains provide fiber, magnesium and B vitamins, and they keep you full longer.
• One quarter: protein. Legumes, nuts, fish, eggs, dairy, poultry; red meat rarely, sausage hardly ever.
• On the side: one to two tablespoons of plant oil (rapeseed, olive), water or unsweetened tea.

---

Amounts per day and per week

Group	Amount	What that looks like in practice
Vegetables	at least 400 g per day	three handfuls: salad at lunch, a vegetable side at dinner, raw vegetables as a snack
Fruit	250 g per day	two pieces, whole rather than as juice
Grains, potatoes	4 to 6 servings per day	rolled oats in the morning, bread, potatoes or rice with one meal
Dairy	3 servings per day	a glass of milk or a cup of yogurt, 30 g of cheese
Fish	1 to 2 times per week	once of those as fatty ocean fish
Meat	no more than 300 to 600 g per week	two to three meals, sausage included
Legumes	several times per week	lentils, beans, chickpeas as a protein source
Nuts	25 g per day	one handful
Oil	2 tablespoons per day	rapeseed or olive oil, butter sparingly
Fluids	1.5 liters per day	water, unsweetened tea; coffee counts
Sugar, salt	little	under 50 g of sugar, under 6 g of salt

---

Where PRAL fits in

PRAL (potential renal acid load) measures whether a food leaves acid or base behind after digestion. Protein and phosphorus act as acids; potassium, magnesium and calcium act as bases. That leads to a simple observation: the two plate quarters for grains and protein are acid-forming, and the vegetable and fruit half is alkaline. A balanced meal that follows the plate rule therefore almost always has a PRAL close to zero.

The reverse is also true: a clearly positive daily value shows that the vegetable half is missing. Not because acid is dangerous, but because the plate is out of balance. That makes PRAL a measure of exactly what “balanced” means.

Two examples from this table:

• Chicken breast with pasta and a little salad (50 g): +12.3 +6.2 −2.2 = +16.3. Protein and grains, no vegetables. Not balanced, and acid-heavy by PRAL.
• Chicken breast with potatoes and vegetables (200 g): +12.3 −13.1 −7.5 = −8.3. The same protein serving, balanced by the plate rule, and alkaline by PRAL.

---

A balanced day

• Breakfast: rolled oats (50 g) with yogurt, an apple and a handful of nuts. PRAL about +3.
• Lunch: lentil and vegetable curry with brown rice, salad with rapeseed oil. PRAL about −5.
• Afternoon: a banana, wholemeal bread with 30 g of cheese. PRAL about 0.
• Dinner: oven-baked salmon (120 g) with potatoes and broccoli. PRAL about −2.
• Drinks: 1.5 liters of water and tea, two cups of coffee. PRAL about −9.

All together, about −13: every group is represented, with two servings of dairy, fish, legumes, whole grains and more than 400 g of vegetables. The PRAL calculator lets you check your own days.

---

Common mistakes and easy fixes

• Vegetables only as garnish. Two lettuce leaves are not half a plate. Fix: put vegetables on your plate first, then the rest.
• Protein only from meat and cheese. Both are acid-forming and high in salt. Fix: replace two meat meals per week with legumes or fish.
• Fruit as juice. A glass of orange juice has the sugar of three oranges and no fiber. Fix: eat whole fruit, and drink juice as a spritzer.
• Forgetting whole grains. White flour provides energy and little else. Fix: switch bread, pasta and rice step by step, and have rolled oats in the morning.
• Forgetting to drink. Thirst is often mistaken for hunger. Fix: drink a glass of water before every meal.