Food allergy is very common. Although 25 percent of people think they're allergic to certain foods, studies show that about only 6 percent of children and 1 to 2 percent of adults have a food allergy. Babies and young children are most often allergic to milk, eggs, wheat, soybean products and peanuts. Some people are allergic to sugar. This doesn't happen with sugars and fats.
Milk allergy is very common and causes diarrhea in adults.
It isn't a true allergy. People with food allergies are allergic to many foods. Food allergy makes people hyperactive. The most common chronic illnesses associated with food allergies are eczema and asthma. Allergy to food dye is common.