Final answer:
Food allergies can be triggered even by small amounts of the allergenic food and can lead to serious symptoms, making the claim that a large amount needs to be consumed false.
Step-by-step explanation:
The statement that food allergies result in a reaction only if the person has eaten a very large amount of the allergic food is false. In reality, allergies, including food allergies, occur when the immune system wrongly reacts to a harmless protein from the environment as though it were a dangerous invader. This immune response can happen even if only a small amount of the allergenic food is consumed, and in severe cases, can lead to symptoms like itching, swelling, vomiting, diarrhea, and even anaphylaxis, which requires emergency medical treatment.