Everyone’s heard that oysters can give lovers a boost in the bedroom, but a lot of foods can have the exact opposite effect.

“In general, eating unhealthily will lower your libido,” says Nashville-based sex therapist David Yarian. “You will have less energy and less vitality, and that translates into less sexual desire.”

Surprisingly, even some relatively healthy foods can deflate desire, most commonly by introducing compounds that alter the delicate balance between the sex hormones testosterone and estrogen. Here’s a list of foods to avoid on a romantic night:

Microwave popcorn. Few things can put you in the mood for love more than watching a good romantic movie in the privacy of your home theater and snuggling with your sweetheart in the dark. Just steer clear of that microwave popcorn. Microwave cooking bags contain the endocrine-disrupting chemical PFOA, which can leach into the popcorn. And messing with your hormones like that can definitely spoil a romantic evening.

Sugar. The sweet white demon is now being blamed for contributing to just about every chronic disease known to man. Now you can add sexual dysfunction to the list, according to the latest nutritional research. Besides rotting your teeth, weakening blood vessels, feeding cancer cells, and throwing blood chemistry out of whack, sugar produces belly fat. That, in turn, lowers testosterone levels, virility, and desire.

Artificial sweeteners. Don’t think you can get around the sugar issue by eating and drinking foods sweetened with chemicals. Aspartame, in particular, is thought to decrease levels of the “happy hormone” serotonin. Researchers have linked the sweetener used in NutraSweet and Equal to both a lowering of the libido and depression.

Deli meat. Here’s another food you should avoid for a variety of reasons, this one mainly due to its high content of salt, fat, and chemical preservatives called nitrates. Oddly enough, it’s the plastic used to wrap the meat that can put a crimp in your sex life. Most plastics contain PVC (polyvinylidene chloride), a chemical that can mimic estrogen, throwing hormones off kilter when it seeps into your baloney.

Dairy products. Cows are often given hormones to ramp up their milk production, and those hormones can wind up in the milk and anything made from it, including cheese, butter, yogurt, and ice cream. But you can still enjoy dairy. Just be sure to use products from cows with hormone-free diets. Organic, grass-fed is best.

Mint. Fresh breath may be conducive to intimacy, but lay off the peppermint and spearmint. Researchers have linked both to a drop in testosterone levels. You’re better off just brushing your teeth.

Soy. This legume is widely thought to be healthy because it has a lot of nutrients and a decent amount of protein for something from the vegetable kingdom. Studies show it also lowers cholesterol. On the dark side, soy contains isoflavones, compounds that have estrogenic qualities that can disrupt hormonal balance. Some studies claim soy reduces testosterone levels and sperm count. The evidence remains inconclusive, but why take chances if you have a hot date?

Beer. Sadly, the ubiquitous brew delivers a double-whammy to the libido. First, it contains alcohol, which is a depressant. Drink too much and it depresses desire in both sexes. Secondly, the hops used as a bittering agent in beer contain phytoestrogens similar to what’s in soybeans. The alcohol can also impede liver function, further fouling up the hormonal system.

In any case, sex therapist Yarian tells Newsmax Health that no single food is likely to make or break your love life.

“People are always looking for a quick fix to everything,” he says. “The truth is that healthy eating and getting enough exercise and sleep may be boring, but it has a cumulative effect. And that’s what will help your sexual function in the long term.”