Experiencing a headache and nausea after eating a meal can be frightening, particularly if it happens consistently. Any one of a number of underlying health issues could be to blame, particularly a food allergy or a food intolerance.

Tapioca flour, or tapioca starch, comes from the cassava plant. This gluten-free starch can help improve the flavor and texture of gluten-free baked goods. Gluten is responsible for building the structure of breads and other baked goods, giving these foods a characteristic chewy texture.

Food allergies occur when the immune system has a negative reaction to the proteins found in a certain food. MayoClinic.com states that 6 to 8 percent of children under age 5 have food allergies, as do 3 to 4 percent of adults.

A food allergy develops when the body has an abnormal response to a certain food or ingredient. In the case of white bread, the allergen is typically wheat. Because symptoms can be extreme and affect the quality of life, it’s important to understand why an allergy to white bread occurs and how you can treat it.

Food allergies can cause swelling and itching of the face, lips, mouth, tongue and extremities, and may be accompanied by hives. Symptoms range from mild to severe, and represent a response by your body's immune system.

Gluten is a protein found in wheat that can cause problems for people whose bodies can't digest it. This condition, known as gluten intolerance or celiac disease, is different from an allergy to wheat or wheat gluten that can cause sinus congestion, runny nose and a sinus headache.

Dairy is a common food allergen that can have a direct effect on your skin. Common skin problems linked to dairy consumption are generally itchy skin, hives and eczema, according to KidsHealth.org. A person with a dairy allergy has a hypersensitivity to the proteins found in cow’s milk.

Gluten and casein are proteins that either add depth and flavor to your food or cause notorious discomfort to your body. The difference stems from your ability to digest both proteins. Gluten is found in wheat, rye and barley, while derivatives include malt, soy sauce and grain vinegar.

Flavonoids are phytonutrients in plant-based food products that often contribute to the color of the foods. They provide antioxidant activity which may play a significant role in cardiovascular health and may help to prevent against diseases such as cancer caused by free-radical damage.

There are a number of reasons people choose to eliminate gluten -- a protein found in wheat, barley and rye - from their diets. Celiac disease is an allergy to gluten that causes irritation in the small intestine and can lead to more serious consequences including skin rash, diarrhea and depression.

Allergic reactions to shellfish or peanuts can be serious or even life-threatening. If you are allergic to one or both of these foods, you should check for their presence in any medications you take. Shellfish is commonly found only in dietary supplements, not prescription medications.

Watery eyes are a minor symptom of gluten intolerance, also called gluten allergy. A gluten allergy is a different condition than celiac disease, which causes the immune system to damage your small intestines when you eat products that contain gluten.