When you're pregnant, your body undergoes immense changes—and so does your mood. You may be over the moon about impending mamahood one day and a bump-bearing basket case the next. Keeping your emotions under control at all times is next to impossible—pregnant or not—but that doesn't mean you're completely helpless. In fact, science suggests that what you eat on a daily basis can have a significant impact on your mental state. That is, consuming a nutrient-rich diet can help create a more positive outlook on your day while eating copious amount of junk food could send you into a deep funk. Want to feel your best? Find out how to nourish your mood. Swinging mood Before diving into the main course, it's important to understand the menu of factors affecting a mama-to-be's temperament. Stress The very thought of motherhood is enough to raise an expectant woman's stress levels. You may be worried about the health of your baby, whether you'll be a good mom or how your pregnancy will progress. Although these concerns are common, too much worry over them can be a bad thing. When brain cells continuously undergo stress signals, they have very little time to recover, which can actually hinder connections to other brain cells and directly impact our thoughts and emotions. Fatigue Considering your body is working on overdrive to meet the needs of both you and your budding baby, it's no surprise you're feeling drained. Extreme exhaustion can negatively impact your frame of mind, so seeking natural energy sources (including food!) will be key. Metabolism Due to an increased metabolism during pregnancy, you need to consume more protein, complex carbohydrates and fat. You'll want to up your caloric intake to meet your body's demands. When your metabolism is stressed, your mood becomes unstable, which can lead to an inability to handle stress—certainly not a domino effect you want to set in motion. Hormones Mood swings caused by hormone fluctuations are most common from weeks 6 to 10 of pregnancy. They tend to level off in the second trimester, but many women experience an encore in the third trimester as their bodies prepare for delivery. Keep these time frames in mind, as sometimes simply knowing why you seem to be all over the map can help you navigate the detours. Food to the rescue You know that eating healthily is critical to provide your baby with vital nutrients, but be mindful, too, that food is also an incredibly powerful tool when it comes to managing your mood. Depending on how you choose to use it, it can hinder the way you feel, or it can dramatically improve your well-being. In addition to ingesting good-for-you fare, you'll also want to steer clear of nutritionally void eats. Because stress causes cortisol levels to rise and cortisol increases food cravings, it's reasonable to want to quell your anxiety over a looming deadline (or due date) with a piece of cake that's as big as your baby bump. In fact, the frosted slice of heaven will actually calm you temporarily. But low-nutrient, sugary foods deplete your neurochemical levels, and once depleted, your mood will be affected. Before indulging your craving for salt and vinegar potato chips or mint chocolate chip ice cream, consider how you will feel afterward, advises Stefanie Senior, RD, a private practice dietician in Toronto. "You should be limiting your amount of processed foods, including refined sugar, foods and beverages with added sugar (i.e., soda) and refined grains, including white bread, white crackers and granola bars, whenever possible," she says. Simple sugars found in white bread make your blood sugar spike—and when you come down from your sugar high, you're likely to feel lethargic. Instead, Senior says expectant ladies should focus their attention on eating natural whole grains and starches such as oats, quinoa, brown rice, yams, squash, peas, beans and lentils. Mamas-to-be should also consume natural sources of sugar from milk, yogurt and fruit. "These complex carbohydrates release sugar more sustainably and will yield a constant source of energy," explains Senior. "Try to eat a carbohydrate source every three to four hours, and combine it with a protein to slow down the absorption of sugar into the bloodstream, which can help manage blood sugar levels, energy levels, appetite and food cravings." Remember: Even-keeled blood sugars equate to even-keeled moods. Additionally, omega-3 fatty acids like EPA may help prevent and manage depression during and after pregnancy. Try incorporating salmon, trout, halibut, herring and mackerel into your regular meal rotations to ensure you meet your quota for DHA and EPA and reap their benefits. Just be sure to avoid predatory fish that are high in mercury, such as king mackerel, swordfish and tilefish. If you're not a fan of fish or are unable to meet your weekly minimum of two servings (5 ounces total), talk to your doctor or dietitian about omega-3 supplements. When it comes to fatigue, you're not doomed to feeling sluggish for nine months. It's natural to feel tired during pregnancy, but remember that food is fuel. Without proper nutrients, energy levels begin diminishing. With adequate intake, however, you'll have more energy and an improved 'tude.