There are plenty of misconceptions when it comes to weight loss, such as all carbs or fats are bad. The best formula for losing weight, according to the National Institutes of Health, is simple: Eat fewer calories than you burn. We’ve singled out five of the biggest myths that muddy the message.

The NIH recently completed a large study, with 811 participants assigned to one of four weight-loss diets with varying levels of fat, carbohydrates and protein — all with individual calorie reduction goals. The subjects were asked to stick to the specified percentages of nutrients and given menu plans. “After two years,” says Catherine Loria, Ph.D., a nutritional epidemiologist at NIH, “we found no difference in weight loss at all.” Still, some carbs are better for dieters than others. Dariush Mozaffarian, M.D., an associate professor of medicine and epidemiology at the Harvard School of Public Health, insists that not all carbs are created equal when it comes to weight loss. He led a study published this year in the New England Journal of Medicine that found that certain carbohydrates, such as refined breads and cereals, do seem more likely to cause weight gain than whole grains.

Um, not really. Loria says that while she hasn’t studied this factor in a specific trial, she’s noticed that the biggest “losers” in weight-loss studies weighed themselves almost every day or every day. “It’s kind of hard for people to get on the scale,” Loria concedes. You need to be aware of your weight, though, to make any necessary corrections in your diet. “There may be a couple of pounds day-to-day fluctuation that’s normal,” she says, “but if you get beyond a couple pounds over your target weight, you probably want to rethink what you’re eating or increase your activity.”

Exercise, obviously, is great for your health in myriad ways — from the psychological (it has been shown to help with depression) to building strong bones with weight-bearing activity. But there’s a caveat, warns Loria: “You have to be careful not to eat more calories than you just expended.” Consult a fitness book or website to learn exactly how many calories your workout requires. That bike ride or long walk may not burn as many calories as you think.

According to the Harvard study, Mozaffarian says, “fat content per se has little relation to which foods or beverages were associated with weight gain.” That doesn’t mean you can eat all the fat you want, of course. Even if calorie control is all that really matters for shedding pounds, we aren’t mere machines: We have to consider our overall health, and the excessive intake of certain fats may increase your risk of important risk factors for heart disease. The NIH advocates a heart-healthy diet, low in saturated fat and trans-fatty acids but high in dietary fiber – whole grain foods, fruits, and vegetables.

This doesn’t work. People who avoid beloved foods nearly always return to their old habits once “The Diet” is over. Loria suggests that rather than choosing a specific diet, people do best by “changing their eating habits so it becomes part of their lifestyle.” Think smaller serving sizes in general, and — for your health’s sake — a balanced diet high in fiber, and low in saturated fats and processed food. One way to develop healthy new habits is by keeping a food diary — even without actually calculating calories consumed, Loria says, so you’re more aware of what you’re eating. The key to keeping the weight off, she adds, “is to make the changes that you think you can maintain for the rest of your life.”