Some people just love to gossip about the health benefits of certain foods (like eating oysters for better sex), but it’s not so great when they end up spreading food myths instead of truths. It’s not that they’re intentionally lying. It’s just that they don’t have the whole story. There are a few myths (or you might call them half-truths) that I hear again and again. Here they are, “busted” with the cold, hard facts. 
Eating oysters helps get you “in the mood.” That oysters or other foods can spark your libido is more fable than fact, according to the U.S. Food and Drug Administration, which reviewed the science on the subject. So why, then, do some people report heightened arousal after eating “aphrodisiacs,”  such as oysters, chocolate or chile peppers? Some experts say that feeling friskier after eating oysters is a little like feeling better after taking a pill that’s really a placebo: it’s all in the mind. But then again, “getting in the mood” is often a state of mind, too, so if you find a food that works for you, go for it. (In the mood for something sweet? Dark chocolate may not boost libido after all, but eating it sure makes us—and our hearts—happy. So indulge! )
Turkey makes you sleepy. Go ahead and have that Turkey & Tomato Panini  for lunch. Turkey alone will not make you feel tired. It’s true that L-tryptophan, an essential amino acid found in turkey and many other protein-based foods, can have a soporific effect on some people. But its effects are blunted by other amino acids in turkey, which compete for the same binding sites in the brain. Lots of other foods, including ground beef and chicken, contain L-tryptophan, too, and don't have this reputation. But turkey is often associated with big meals such as Thanksgiving—which make you sleepy because a full stomach means that blood is directed away from other bodily functions and systems, including your nervous system.
Food allergies can make you fat. Food allergies may cause symptoms like hives, gastrointestinal or respiratory distress.  (In severe cases, they progress to anaphylaxis, a potentially fatal condition.) But there is no evidence at all to suggest that food allergies contribute to weight gain, says Brian Smart, M.D., an allergist with DuPage Medical Group in Glen Ellyn, Illinois. “Food allergy is related to IgE antibodies and these have no influence at all on hormones that affect weight, such as thyroid hormone, growth hormone or insulin, or on any other regulatory process that can affect overall metabolism.”
So, the moral of this story: “food gossip” is fun but it’s not always true…