"Sometimes people can feel unmotivated because they lose sight of why they're making changes in the first place," says Edwina Clark, R.D., head of nutrition and wellness at Yummly. The reason why you're losing weightshould be as specific and unique to you as possible. Not only will having a mission statement on tap help you build momentum in the beginning, it will help you refocus after any setbacks you experience along the way. 

"Lack of motivation can be a symptom of other factors, such as fatigue, high stress levels, and feeling overwhelmed," says Clark. Explore why you're feeling unmotivated and create strategies to help you fight back. For example, you can use what's holding you back to define the parameters of your goals. If you're terrified of failure, for example, you might start with changes that take five minutes or less, like making a smoothie or meditating. By the time you start talking yourself out of it, you'll have already checked it off your to-do list (and boosted your confidence in the process).

Creating a game plan can be overwhelming, especially if you have no idea where you're starting. Enter, food journaling. Tracking your intake can make you feel more in control of your eating habits, and in turn, motivated to make small changes to your current diet. "Because you're making small modifications to your current behaviors, as opposed to trying to adhere to a new diet altogether, many find it more sustainable, as well as educational," says San Diego-based culinary dietitian Nancy Snyder, R.D. In time, you'll have proof of the legit progress you're making, which can help you stay motivated over the long haul.

Just make sure you approach the process with an opportunistic mindset for setting goals, not as a forced recalling of "good" and "bad" behavior, says Snyder. That will make you lose sight of the big picture.

No, but seriously. "Focusing on numbers can only result in frustration if there's a plateau or if the degree of weight loss isn't what's expected or desired," says Adrienne Youdim, M.D., director of the Center for Weight Loss and Nutrition in Beverly Hills. "In the long run, this results in sabotage." Instead, set small goals that aren't weight-related—such as swapping out your usual 2 p.m. soda with sparkling water, going for a walk after dinner, or adding a side of veggies to your meals. To prevent feeling overwhelmed, focus on one goal at a time. "Trying to overhaul your entire lifestyle at once is incredibly difficult and ultimately leads to disappointment," says Clark. "Knocking off goals one by one builds confidence and self-efficacy."

Once you've decided what your first goal is going to be, you have to put all the pieces in place to make sure that happens, says Susan Bowerman, R.D., director of nutrition at Herbalife. If your first goal is to pack a healthy lunchthree times a week, for example, you need to choose lunch recipes, shop for the food you need, buy storage containers, and set aside time to prep your meals. Making sure you have what you need within arms reach will ensure that you'll actually follow through.

It takes time to replace a bad habit with a good one, so keep practicing until your new habit feels natural and comfortable, says Bowerman. Then, keep a log as proof that you're meeting your goals. "No matter how insignificant your goals may seem—I once had a patient whose only goal was to switch from whole milk to 2 percent—having that proof in hand encourages you to keep practicing your new habits," she says.

Fails are inevitable—so instead of letting them defeat you, use them as a learning experience. "Many of the behaviors you're trying to change have been with you for a long time," says Bowerman. "Try to figure out what leads you to slip up, and figure out how you can prevent it from happening again." Then, you can try to make it up to yourself by balancing the scales. If you went overboard on birthday cake at your friend's shindig, for example, then eat an extra serving of veggies the next day.