Are you doing everything right but not able to drop a pound? Or you’re eating only healthful foods but still aren’t feeling great?

Maybe what you think you know isn’t so accurate after all. Cardiologist Dr. Mike Fenster, author of The Fallacy of the Calorie as well as a chef and martial artist, offers these eight myths many of us have assumed were true.

MYTH 1: “Light” salad dressing is a great option.
Salad dressings, low-fat or regular, tend to be packed with omega-six polyunsaturated plant oils which, according to Fenster, are associated with an increased risk of cardiovascular problems. “When opting for salad, stick with just a little olive oil, vinegar, fresh lemon juice or nothing at all,” he recommends.

MYTH 2: For health, choose deli meat over burgers.
Whereas typical deli sandwiches are made with highly processed meat, which has shown to be associated with heart disease, cancer and mortality, fresh red meat in hamburgers has not indicated that same association, according to Fenster. “Many restaurants today, outside of the fast food variety, offer freshly ground, quality burgers,” he notes. “Some even use beef that’s organic, grass-fed and pasture-raised.”

MYTH 3: Diet drinks are safe.
“The common misconception that you can avoid or compensate for poor food choices with diet drinks is a double-edged exercise in futility,” Fenster says. “In fact, studies have shown that women who drink more diet drinks are heavier and have an increased risk of diabetes and heart disease.”

MYTH 4: Don’t salt your food.
A properly seasoned meal will leave you more satisfied and less likely to binge later in the day, Fenster says. In addition, adding salt to fresh food accounts for only about 5% of the daily intake; more than 75% of an average person’s daily sodium intake comes from eating highly processed and prepared foods. Eat fresh, and you can add a little table salt without worry.

MYTH 5: Choose low-cholesterol foods.
Fenster says that the cholesterol consumed has little to do with blood cholesterol levels. “Foods promoted as ‘low in cholesterol’ are often loaded with fat, sugar or other additives that cause more harm than a three-egg omelet ever could,” he adds.

MYTH 6: Bars are the new super food.
While they’re marketed as a nutritious choice, energy bars, protein bars and granola bars often are highly processed and contain high levels of low-nutrient fillers and sweeteners like high fructose corn syrup, according to Fenster. “Diets high in added sugars—fructose in particular—have been associated with an increased risk of developing hypertension, obesity, cardiovascular disease and other life-threatening medical conditions,” he says. “Bars are also often loaded with artificial sweeteners such as aspartame, which is linked to myriad ailments.” Any short-term energy boost the bars provide are often followed by a crash that can cause you to eat yet more unhealthy bars to get revved back up.

MYTH 7: Bagels are more healthful than bread.
Really, bagels are just white bread in a different form. In fact, Fenster points out, each of today’s big bagels is equivalent to several slices of white bread and may contain significant amounts of refined sugar and fat in the form of detrimental omega-six polyunsaturated fatty acids.

MYTH 8: Count calories for weight control.
“The caloric content of a food or beverage item doesn't have much to do with how we actually metabolize our food,” Fenster believes. “Additionally, calories alone do not accurately reflect a food’s nutritional value. For example, a 100-calorie soft drink is not the nutritional equivalent of a 100-calorie apple. Healthful eating isn't about focusing on the quantity of calories, but rather about the quality of the consumable.”