Some persistent food and health myths just don't seem to go away. To really be healthy this summer, stick to common sense and don't get duped by these five summer food myths.

The Myth: Garlic is a natural mosquito repellent.
The Truth: Garlic wards off vampires, but it won't keep mosquitoes at bay. Researchers at the University of Connecticut tested the theory without success, although they did suggest that perhaps participants hadn't eaten enough garlic to see results.

The Myth: Doing crunches is the only way to get a flat belly.
The Truth: Crunches may help tone your belly, but they're not the only route to a flatter stomach. Eating whole grains, such as quinoa, brown rice or bulgur wheat, may actually help you shed belly fat. People who ate 3 servings of whole grains (such as a 1/2 cup of cooked oatmeal, a slice of whole-wheat bread and 1/2 cup of cooked brown rice) a day lost more weight and, specifically, more abdominal fat than those who ate less than a quarter of a serving, according to findings reported in a study in The Journal of Nutrition.

The Myth: Watermelon's tasty, but not terribly nutritious.
The Truth: Even though watermelon is very watery (read: hydrating) and low in calories (only 46 per cup!), it packs a healthy nutrition punch. In addition to some vitamin C (20% of the Daily Value per cup), watermelon delivers lycopene-the same red-tinged antioxidant found in tomatoes, linked to a lower risk of certain cancers.

The Myth: Buying fresh produce at farmers' markets is expensive.
The Truth: Farmers' markets might seem more expensive than grocery stores, but prices at farmers' markets for conventionally grown produce items were lower than they were at supermarkets in a study conducted by Jake Robert Claro for the Northeast Organic Farming Association of Vermont, according to a blog on the topic written by Barry Estabrook. The same was true for organic produce.

The Myth: Raw foods are healthier than cooked foods.
The Truth: Raw-foodists claim that eating food in its raw state preserves all its nutrients, including enzymes that get destroyed by cooking. They make a point…kind of. Cooking can destroy water-soluble vitamins, such as vitamin C, but it also makes other nutrients, like lycopene in tomatoes, more absorbable. While cooking does break down, or "denature," enzymes, so does stomach acid. Meaning that even if you preserve the enzymes by sparing them the cooking process, most of the enzymes will be destroyed through digestion anyway. This is not to say that eating a raw-food diet is necessarily unhealthy. On the contrary, a 2005 study in The Journal of Nutrition found that raw-foodists were far less likely than the general population to register high levels of "bad" LDL cholesterol. On the flip side, 38% of the study's 201 subjects were deficient in vitamin B12, a nutrient that's also important for heart health.

What summer myth do you want to know the truth about?

Kerri-Ann, a registered dietitian, is the associate editor of nutrition for EatingWell Magazine, where she puts her master's degree in nutrition from Columbia University to work writing and editing news about nutrition, health and food trends. In her free time, Kerri-Ann likes to practice yoga, hike and paint.