diff --git a/nextcloud_mcp_server/models/cookbook.py b/nextcloud_mcp_server/models/cookbook.py
index c058989a..a53f79ba 100644
--- a/nextcloud_mcp_server/models/cookbook.py
+++ b/nextcloud_mcp_server/models/cookbook.py
@@ -2,7 +2,7 @@
 
 from typing import List, Optional, Union
 
-from pydantic import BaseModel, ConfigDict, Field
+from pydantic import BaseModel, ConfigDict, Field, field_validator
 
 from .base import BaseResponse, IdResponse, StatusResponse
 
@@ -40,6 +40,36 @@ class Nutrition(BaseModel):
 
     model_config = ConfigDict(populate_by_name=True)
 
+    @field_validator(
+        "calories",
+        "carbohydrateContent",
+        "cholesterolContent",
+        "fatContent",
+        "fiberContent",
+        "proteinContent",
+        "saturatedFatContent",
+        "servingSize",
+        "sodiumContent",
+        "sugarContent",
+        "transFatContent",
+        "unsaturatedFatContent",
+        mode="before",
+    )
+    @classmethod
+    def coerce_to_str(cls, v: object) -> object:
+        """Coerce numeric values to strings.
+
+        The schema.org/NutritionInformation spec allows values as either
+        strings (e.g. '650 kcal') or numbers (e.g. 650). Nextcloud Cookbook
+        stores whatever the source provided.
+        """
+        if isinstance(v, bool):
+            msg = "boolean values are not valid for nutrition fields"
+            raise ValueError(msg)
+        if isinstance(v, (int, float)):
+            return str(v)
+        return v
+
 
 class RecipeStub(BaseModel):
     """Stub of a recipe with basic information."""
diff --git a/tests/unit/test_nutrition_model.py b/tests/unit/test_nutrition_model.py
new file mode 100644
index 00000000..4e9870b4
--- /dev/null
+++ b/tests/unit/test_nutrition_model.py
@@ -0,0 +1,74 @@
+"""Unit tests for Nutrition model numeric coercion (issue #708)."""
+
+import pytest
+from pydantic import ValidationError
+
+from nextcloud_mcp_server.models.cookbook import Nutrition
+
+NUTRITION_FIELDS = [
+    "calories",
+    "carbohydrateContent",
+    "cholesterolContent",
+    "fatContent",
+    "fiberContent",
+    "proteinContent",
+    "saturatedFatContent",
+    "servingSize",
+    "sodiumContent",
+    "sugarContent",
+    "transFatContent",
+    "unsaturatedFatContent",
+]
+
+
+@pytest.mark.unit
+@pytest.mark.parametrize("field", NUTRITION_FIELDS)
+def test_nutrition_field_accepts_string(field: str):
+    """String values should be accepted as-is for every nutrition field."""
+    n = Nutrition(**{field: "650 kcal"})
+    assert getattr(n, field) == "650 kcal"
+
+
+@pytest.mark.unit
+@pytest.mark.parametrize("field", NUTRITION_FIELDS)
+def test_nutrition_field_coerces_int(field: str):
+    """Integer values should be coerced to strings for every nutrition field."""
+    n = Nutrition(**{field: 260})
+    assert getattr(n, field) == "260"
+
+
+@pytest.mark.unit
+@pytest.mark.parametrize("field", NUTRITION_FIELDS)
+def test_nutrition_field_coerces_float(field: str):
+    """Float values should be coerced to strings for every nutrition field."""
+    n = Nutrition(**{field: 260.5})
+    assert getattr(n, field) == "260.5"
+
+
+@pytest.mark.unit
+@pytest.mark.parametrize("field", NUTRITION_FIELDS)
+def test_nutrition_field_accepts_none(field: str):
+    """None should remain None for every nutrition field."""
+    n = Nutrition(**{field: None})
+    assert getattr(n, field) is None
+
+
+@pytest.mark.unit
+@pytest.mark.parametrize("field", NUTRITION_FIELDS)
+def test_nutrition_field_rejects_bool(field: str):
+    """Boolean values should not be silently coerced to strings."""
+    with pytest.raises(ValidationError):
+        Nutrition(**{field: True})
+
+
+@pytest.mark.unit
+def test_nutrition_mixed_types():
+    """Nutrition model should handle a mix of string, int, and None values."""
+    n = Nutrition(
+        calories="650 kcal",
+        proteinContent=18,
+        fatContent=None,
+    )
+    assert n.calories == "650 kcal"
+    assert n.proteinContent == "18"
+    assert n.fatContent is None