Our bodies require food but food covers a lot of different things and sometimes that food can be damaging or upsetting to people suffering allergies and various medical conditions. Sometimes whether the food is cooked or uncooked can be a deciding factor as well.
Certain people also react to food whether it is processed or unprocessed. Types of food such as carbohydrates, protein, fat and various nutrients can have adverse results as well. But our reactions to food at not necessarily immediate, obvious or severe enough to warrant direct investigation. We just don't feel that we are operating at 100% sometimes.
Eating an unbalanced diet can be a problem. Too much of certain types of food can create imbalances in your body chemistry as well. Food that is too rich, too sweet or too salty can cause problems even it is tastes good to us. Our bodies can fail to process certain foods for a variety of reasons.
Allergies and reactions can occur when our immune system misidentifies a normally harmless food as a foreign attack on the body. The immune system will then mount a vigorous defense to protect the body from what is otherwise a harmless energy giver. The food itself is not the problem but the body's reaction and its defense mechanism that is activated to combat it. This is a standard "allergic reaction."
Some allergic reactions are so severe to certain foods (peanuts, for example) that even a very small amount can cause a deadly immune reaction that can result in severe incapacitation and even death.
In other instances, the body simply doesn't process the food appropriately. This can lead to conditions such as diabetes. Diabetes results when the pancreas fails to produce enough (or any) of the insulin that the body requires to process carbohydrates and sugars. When no insulin is being produced it is called Type 1 diabetes. This is often discovered in children, teens and young adults.
When insulin is being produced but not enough to do the job it is called Type 2 diabetes and is usually diagnosed in older people (generally over the age of 40).