(CNN) -- Can't sleep? Got the PMS blues? Before you open your medicine cabinet, step into your kitchen.
"Real, whole, fresh food is the most powerful drug on the planet," says the author of "The Blood Sugar Solution" cookbook, Dr. Mark Hyman. "It regulates every biological function of your body." In fact, recent research suggests not only what to eat but when to eat it for maximum benefit. Check out the latest smart food fixes.
Problem: I'm bloated
Food fix #1: Dig in to juicy fruits and vegetables
When you're feeling puffy, you may not want to chow down on watery produce, but consuming foods like melon, cucumber and celery is an excellent way to flush out your system, says the author of the book "Food & Mood," dietician Elizabeth Somer.
"We need sodium to survive," she explains, "but because we often eat too much of it, our bodies retain water to dilute the blood down to a sodium concentration it can handle. Eating produce with high water content helps the dilution process, so your body can excrete excess sodium and water."
Food fix #2: Load up on enzymes
Bloating can also be a sign that your intestines are out of whack. "If you're irregular or experience gas right after eating, papaya can help," explains the author of the book "Food as Medicine," Dr. Dharma Singh Khalsa. "Eating 1 cup several times a week helps rejuvenate the gastrointestinal system, thanks to papaya's digestive enzyme papain, which breaks down protein."
The fiber also helps push food through your intestines, improving regularity. Try a smoothie with papaya, pineapple (it also contains digestive enzymes), protein powder, ice and almond milk.
Problem: I'm on an emotional roller coaster
Food fix #1: Say yes to breakfast
"People who eat within an hour or two of waking up have a more even mood throughout the rest of the day and perform better at work," Somer says. British researchers found that study participants who skipped their morning meal did worse on memory tests and were more tired by midday than those who had eaten.
The optimal breakfast includes a whole grain to supply glucose for your brain to run on, protein to satisfy hunger and keep your blood sugar levels steady and one or two antioxidant-rich fruits or vegetables. Somer's suggestion: a 100% whole-grain cereal that contains at least 4 grams of fiber and no more than 5 grams of sugar, eaten with fruit and low-fat milk.
Food fix #2: Stock up on selenium
A lesser-known trace mineral, selenium -- found in Brazil nuts, tuna, eggs and turkey -- helps keep you on an even keel. Women whose diets are deficient in the mineral are more prone to feeling depressed.
Why? Selenium is crucial for the production of thyroid hormones, which govern metabolism and mood. You don't need much, though: The recommended daily allowance for selenium is 55 micrograms, and you can get that amount by eating one 3-ounce can of tuna.
Problem: My skin is acting up
The food fix: Eat your onions
Battling breakouts? The antioxidants in onions and other sulfur-rich veggies tamp down the inflammation that leads to acne, says Dr. Valori Treloar, a dermatologist in Newton, Massachusetts, and co-author of the book "The Clear Skin Diet." The sulfur in onions, leeks and scallions helps produce a detoxifying molecule called glutathione, which a 2011 study found to be lower in the skin of people who were prone to breakouts.
This antioxidant is most potent when eaten in raw or lightly cooked foods. Try adding chopped scallions to your salad or stirring diced onions into your salsa or stir-fry. Taking folate and vitamin B6 and B12 supplements may also boost glutathione levels.
Problem: I get crazy-bad jet lag
The food fix: Don't snack on the plane
It's no fun spending the first days of your vacation trying to acclimate. One surprising secret to avoiding the headaches, irritability and upset stomach of jet lag is to fast for several hours before arriving at your destination. That's because when you eat influences your circadian rhythms, in much the same way that exposure to light and dark does.
Let's say you're headed to France. On the plane, steer clear of most food (but drink plenty of water), set your watch to Paris time and eat a high-protein breakfast at 7 a.m., no matter where you are on your trip.
"The fast depletes your body's energy stores, so when you eat protein the next morning, you get an extra kick and help your body produce waking-up chemicals," explains Dave Baurac, spokesperson for the Argonne National Laboratory, a research institute based in Illinois.
Problem: I'm tossing and turning
Food fix #1: Have a late-night morsel
We've all been told to avoid eating too close to bedtime, but applying this rule too strictly could actually contribute to sleep woes. As anyone who has tried a fast knows, hunger can make you feel edgy, and animal studies confirm this.
"You need to be relaxed to fall asleep, and having a grumbling stomach is a distraction," explains Kelly Glazer Baron, an instructor of neurology at Northwestern University and spokesperson for theAmerican Academy of Sleep Medicine. "It makes it hard to get to sleep and wakes you up at night."
The trick is to tame the munchies 30 minutes to an hour before bed with a small snack that includes complex carbohydrates. "Since you metabolize sugars more slowly at night, a complex carb like whole wheat is a better choice," Baron says. "It keeps your blood sugar levels even." Try cheese and whole-wheat crackers or almonds and a banana.
Food fix #2: Add cherries
You can boost your snack's snooze power by washing it down with a glass of tart cherry juice. A recent study of folks with chronic insomnia found that those who downed 8 ounces of juice made from tart Montmorency cherries (available in most grocery stores) one to two hours before bedtime stayed asleep longer than those who drank a placebo juice.
These sour powerhouses -- which you can eat fresh, dried or juiced -- possess anti-inflammatory properties that may stimulate the production of cytokines, a type of immune-system molecule that helps regulate sleep. Tart cherries are also high in melatonin, a hormone that signals the body to go to sleep and stay that way.
Problem: I have wicked PMS
The food fix: Keep an eye on iron
You might be more susceptible to the monthly blahs if you have low levels of iron, according to a new study. Researchers looked at the diets of 3,000 women over 10 years and found that those who consumed more than 20 milligrams of the mineral daily had about a 40 percent lower risk of PMS than those who ingested less than 10 milligrams.
You can get almost your full daily dose by eating 1 cup of an iron-fortified cereal; other great sources include white beans (4 milligrams per one-half cup) and sautéed fresh spinach (3 milligrams per one-half cup).
Problem: I'm so sensitive to the sun
The food fix: Pile on protective produce
While you still need the usual sun protection (SPF 30 sunscreen as well as a wide-brimmed hat), you may be able to bolster your skin's own resistance to UV rays with what you eat. The details: Micronutrients called carotenoids in fruits and vegetables protect the skin against sunburn, recent science shows.
"Most topical sunscreens work by filtering out the UV component from the solar light that reaches the skin," explains researcher Wilhelm Stahl, a professor of biochemistry at Heinrich Heine University in Düsseldorf, Germany. "But these micronutrients, if you have enough in your system, actually absorb UV light and prevent damage."
The most potent carotenoids are the beta-carotene found in carrots, endive and spinach -- and the lycopene in watermelon and tomatoes. Keep in mind that the effect isn't instantaneous; you would need to eat a carotenoid-rich diet for at least 10 to 12 weeks in order to get the full benefit, says Stahl. Still, there is a reward for your patience: skin fortified to fend off sun damage and wrinkles.