Food Allergy vs Food Intolerance vs Food Sensitivity: What's the Difference?

Have you ever noticed that certain foods leave you feeling bloated, tired, uncomfortable or simply not yourself?

Food-related symptoms can be frustrating, particularly when you struggle to identify which foods are responsible. Some reactions happen almost immediately, while others appear hours later, making it difficult to recognise a consistent pattern.

Terms such as food allergy, food intolerance and food sensitivity are frequently used interchangeably, but they describe very different physiological mechanisms.

What Is a Food Allergy?

A food allergy involves the immune system reacting to a particular food protein. In an immediate, IgE-mediated allergy, the immune system mistakenly identifies a normally harmless substance as a threat, triggering an allergic response.

Symptoms may include itching, hives, facial swelling, digestive cramping or wheezing. Common allergens include peanuts, tree nuts, eggs, milk, wheat, fish and shellfish. Food allergies can be serious and require appropriate medical diagnosis.

What Is a Food Intolerance?

Unlike an allergy, a food intolerance does not involve the immune system creating antibodies against proteins. Instead, it typically stems from a chemical, enzyme or digestive limitation. For instance, lactose intolerance occurs when the body produces insufficient lactase enzyme to break down milk sugars.

Histamine intolerance is another common example: when the body has reduced DAO enzyme activity to degrade histamine from aged cheeses, wine, or fermented products.

What Is a Food Sensitivity?

Food sensitivities often involve delayed, non-IgE immune pathways or increased intestinal permeability ('leaky gut'). Reactions might appear 24 to 72 hours later, causing joint stiffness, fatigue, migraines, or brain fog.

The Conscious Nutrition Approach

Rather than permanently eliminating half of your diet, our goal is to identify active triggers, support the gut barrier, and restore digestive tolerance so you can enjoy a wide variety of nourishing foods.