Weight gain aside, I would rarely think of any other complications or side effects the food may cause. Side effects are attributed to medications or medical procedures, but not food, right? Well, guess again. Turns out, the food we eat may also cause side effects. Some side effects are serious, some are disturbing, and some may put you into embarrassing situation.

1. Body Odor. Researchers found that red meat consumption negatively influences on body odor [1].
   


2. Acne. Foods that are high in saturated fat and trans fatty acids increase the sebum production in the body, which in turn increases acne. Researchers suggest that there is a positive association between milk consumption and acne.


3. Allergy. Allergy is a number one foods side effect. In theory, any food can cause an allergy. But in fact there are 8 foods to blame for 90% of allergic reactions to food: milk, eggs, peanuts, tree nuts (including Brazil nuts, hazelnuts, almonds and walnuts), fish, shellfish, soy and wheat.


4. Candidiasis (Yeast infection). Yeast infections are caused by an overgrowth of the normal yeast in the body, so foods that affect the yeast levels may contribute to a yeast infection. These foods are: sugars, vinegar, starches, refined carbohydrates, yeast and yeast containing products.


5. Heartburn and Acid Reflux. There is a relatively long list of foods that cause heartburn. Some foods cause the lower esophageal sphincter - a muscle that helps to keep stomach contents out of the esophagus - to become weaker, and some cause the stomach to produce more acid than usual. Both of these problems can increase acid reflux. Most common food triggers for heartburn are citrus fruits, fried and fatty foods, vinegar, tomatoes, chocolate.


6. High Cholesterol (Hyperlipidemia). Cholesterol is found mostly in animal foods. Consumption of cholesterol-rich foods can elevate blood cholesterol level, which may increase the risk of heart attack or stroke. High cholesterol foods are: brains (beef, pork, lamb), eggs, organ meat (liver, kidneys, spleen).
   


7. Kidney stones. People whose diets are high in animal protein and low in fiber and fluids may be at higher risk for stones. Several studies have shown that increasing dietary calcium and restricting salt, animal protein, and foods rich in oxalate, such as rhubarb, spinach, cocoa, nuts, pepper, and tea, can help prevent calcium oxalate stones from returning [2].


8. Memory and Cognition Impairment. Among older adults whose diets are high in saturated fats and trans fats, a high intake of foods containing copper may cause a fast decline in their ability to think, learn, and remember, according to the study from Rush University Medical Center in Chicago [3]. The research studies have linked fat intake, especially that of saturated and trans fats, to Alzheimer's disease and other forms of cognitive difficulties.


9. Edema and Water Retention. Foods high in salt, sodium or sugar may cause the body to retain considerable fluids and worsen edema. The body needs a constant concentration of salt in its tissues. When excess salt is taken in, the body dilutes it by retaining fluid.
   


10. Migraine and Headache. Foods may trigger not only migraine but also tension type headache, which feels like tightening of a band around the head, making the whole head ache. Foods cause headaches by affecting the brain chemistry or changing the size of blood vessels. Certain foods cause headache in most vulnerable people because of their high content of the amino acids tyramine and phenyethyamine. The tyramine increases blood flow to the brain, which can lead to a headache. Common headache food triggers are aged cheese, beer, red wine, chocolate, nitrite-containing foods.