Dietitians Share the 12 Biggest Mistakes That Prevent Weight Loss

Extreme dieting usually involves overexercising and extreme calorie restriction — you never want to dip below 1,200 calories per day. Registered dietitian Leslie Langevin, MS, RD, CD, of Whole Health Nutrition, says "cutting out too much" isn't sustainable. Find a nourishing, simple (yet delicious) way of eating that offers you enough calories, nutrients, and energy to live a healthy, happy life, whether that's by eating a plant-based diet, going Mediterranean, or following another nutritious eating plan.

Saying no to bread, chocolate, cookies, or french fries can be downright depressing. Since including these foods in small amounts on a regular basis can help prevent an urge to go overboard later, registered dietitians Stephanie Clarke, RD, and Willow Jarosh, RD, of C&J Nutrition encourage clients to have a "treat bank" of 150 to 200 calories each day. Or find healthier ways to indulge — these three-ingredient healthy brownies are 141 calories!

While you shouldn't swear off sweets forever, the typical Western diet tends to be high in sugar, refined carbohydrates, and processed food. It's not just the empty calories you need to worry about; it's how these foods affect your insulin. Jason Fung, MD, a nephrologist (kidney specialist), explained that processed carbs and sugary foods such as ice cream, cookies, muffins, crackers, bagels, and white bread spike your insulin levels, which can causes weight gain.

Aside from being high in carbs and calories, these foods don't offer your body any nutrition, so you end up feeling hungry, which makes you eat more. Eating sugary foods also increases your cravings for them, another contributor to overeating.

Every bite, taste, spoonful, and handful adds up, so if you're not keeping track of your daily calorie intake, it's easy to go over. Follow a diet with appropriate calories for your needs, because eating too much can lead to greater fat deposits, explained Seattle-based registered dietitian nutritionist and Arivale Coach Ginger Hultin, MS, CSO.

Figure out your daily calorie needs either by meeting with a dietitian, or by using this formula. Measure and weigh your food, and track your intake by writing it down in a food journal or by using an app like MyFitnessPal. Once you get in the habit, you will start to understand portion size better, too.

Stephanie Clarke also recommends planning ahead as much as possible, because when hunger strikes and you're not prepared, that's when unhealthy decisions are made (hello cookies for lunch!).

At the beginning of the week, plan out your meals and snacks, then hit the grocery store to stock up on everything you need from eggs, to veggies, to the containers you need to make a week of salads. It means that you'll have the food you want to eat on hand when you want to eat it, "which is the key for sticking to healthy eating for the long term," Stephanie said.

Working out just so you can eat more, or eating a ton and "punishing" yourself with a grueling workout to burn it all off not only promotes an unhealthy relationship with food, but it can also lead to weight gain, warns Stephanie.

A 30-minute run only burns about 250 calories, so if you devour 300 calories worth of dessert, it's no wonder you're not losing any weight and actually gaining instead. Use workouts to complement your healthy diet, not to make up for unhealthy eating habits.

Having the support of everyone around you will make it much easier to stay on track with your a weight-loss goals, so don't go at it alone! Willow suggests telling your family, friends, gym buddies, and co-workers that you're trying to lose weight, so instead of suggesting going out for ice cream after work, they'll invite you for a predinner workout. They'll keep you fired up about your goals, and be there to celebrate when you conquer them.

Drastically reducing your daily calorie intake seems like the simplest and easiest way to lose weight, which is why many people try it. "While calorie deficit is a must for weight loss," registered dietitian Lisa Bunn, director of nutrition at the Genavix Wellness Network said, "the nuance is that we don't want it to be too much of a deficit."

Without enough food for survival (including our normal daily functions), your body will send signals to conserve calories, slowing down your metabolism. Your body will then choose to get its energy from a more efficient source than our fat stores — our muscles. The American College of Sports Medicine recommends that women should eat at least 1,200 calories per day, and men should eat at least 1,800.

Your kale salads and HIIT workouts are on point all week, so when the weekend rolls around, you deserve a little reward, right? Not so fast. "One cheat day can undo all the weight-loss work you've put in during the week," warns Willow. If you devote an entire day to eating foods that don't push you toward your goal, "the only person you're cheating is yourself . . . and that's not good in the short term or long term." Plus, a cheat day can easily turn into a few cheat days, making it harder to get back on track.

Instead, stick to the one small treat each day to satisfy your cravings, and you shouldn't need a whole day to let loose. It also helps to make sure the healthy foods you're eating are enjoyable. Take a healthy cooking class, order a plant-based cookbook — get excited about the healthy meals you're eating and you'll be loving your food so much, you won't need a "cheat day."

Vegetables are the food group you want to be filling up on the most. "They are high in volume and weight and fill up our stomachs, which helps us register the feeling of fullness," Ilana said. Stephanie and Willow agree and say that veggies are also high in fiber, so they'll satiate your hunger longer, helping you consume fewer daily calories.

Leslie adds that veggies aren't just for dinner! She said to include veggies in every single meal and snack. During breakfast, throw greens or beans in fruit smoothies or add spinach to overnight oats or zucchini to oatmeal. For lunch, make a week of mason jar salads to ensure you get a daily salad. And for dinner, make sure your plate is half-filled with veggies like cauliflower rice or roasted sweet potato.