Updated

When it comes to bad weight loss recommendations, dietitians have heard it all from their clients. Here are the tips they wish you'd stop believing, plus some proven strategies to use instead. (Get a flat belly in just 10 minutes a day with this reader-proven plan!)

"Stop eating gluten."
We've said this before, but let's say it again: Unless you have celiac disease or non-celiac gluten sensitivity, there's no reason to eliminate gluten from your diet, and there's no evidence that doing so will help you shed pounds.

"Going gluten-free just makes eating more expensive, takes good-tasting bread and pizza off the menu, and doesn't guarantee a lower calorie intake," said Georgie Fear, RD, author of “Lean Habits for Lifelong Weight Loss.” "Even if going gluten-free keeps you away from pasta and bread, there are plenty of gluten-free goodies like cookies and cake that sneak all those calories back into your diet anyway."

Instead, keep enjoying gluten-containing foods in moderation, like everything else. (These 9 proven ways to lose stubborn belly fat, on the other hand, are based on sound research.)

"It's all about exercise."
You might have heard the phrase you can't outrun a bad diet—and it's true.

"I've had clients place exercise on a pedestal above diet and other lifestyle behaviors," said Devon Golem, PhD, RD, director of the Didactic Program in Dietetics at New Mexico State University."

Truth is, scientific evidence reveals that diet alone is more effective than exercise alone when it comes to short-term weight loss. And for long-term weight loss, you need a combination of diet, exercise, and other lifestyle behavior changes." (Have more than 50 pounds to lose? Here are 10 tips for getting started.)

"As long as it's healthy, you don't have to watch how much you eat."
We know, we know—nobody likes breaking out the measuring cups and spoons. But portions really do matter, especially when it comes to calorie-dense fats, explained Lisa Young, PhD, RD, nutrition professor at NYU and author of The Portion Teller.

"I have had clients who have actually gained weight by thinking this way," she said. "Nuts, avocados, and olive oil are healthy fats—but you have to watch your portions!" Luckily, we've got an easy primer on proper serving sizes right here.

"Taking a cheat day will keep your metabolism up."
Sorry, cheat day lovers: The big increase in calories you eat on a cheat day will probably be stored as body fat, Fear explained.

"The best way to keep your metabolism up and lose fat is not to down a whole pizza on Sunday, but to eat some carbs every day, strength train several times a week, get enough sleep, and eat within your calorie needs—every day of the week," she said.

"Diet and exercise are the only things you need to worry about."
Sleep, stress, and environment all play a huge role in your weight loss efforts.

"The link between sleep and weight is undeniable: The less we sleep, the more we weigh," Golem said. "Stress is another factor that needs to be considered, especially if food or alcohol is being used as a calming strategy. Chronic stress not only influences appetite-regulating hormones, but it also affects hormones that regulate the way your body burns calories."

It also pays to consider your environment, Golem explains. Research shows that people who keep unhealthy foods like soda or cookies on the kitchen counter can weigh up to 20 pounds more than those who don't, so take a look at what kinds of foods you're regularly stocking at home and at work. (Need more motivation? Check out these 8 things that happen when you finally stop drinking diet soda.)

"Buh-bye to all the unhealthy food in my life."
Go ahead and break out your happy dance: You don't need to cut out fries or ice cream (or whatever "bad for you" foods you love) completely.

"There's room for fatty, sugary, and salty foods, as well as alcohol," Golem said. "It's a matter of eating well the majority of the time."

Besides, making your diet too strict will likely backfire, leading to deprivation and bingeing. How can you actually achieve moderation?

"Setting boundaries," Golem said. "For example, I love desserts, but they're one of my trigger foods—I have a hard time eating a proper serving size when they are around. So, my boundaries for desserts are that I eat a single portion just once a week—on Friday nights."

This article originally appeared on Prevention.com.