Losing weight is hard work. It takes staying committed to cutting calories, monitoring portion sizes and making time for exercise. To get the work done — day after day, week after week — you may find yourself looking for motivation in the falling numbers on your scale, measuring tape or clothing tag.

But when those numbers stall, it can feel frustrating, gut-wrenching, totally demotivating — leaving you wondering how you're going to break your weight loss plateau.

"Oftentimes, when I ask someone why they think they've gained weight or stopped losing it, they'll mention exercise — either that they're not being active enough or they can't find time for it," explains Dr. Nabil Tariq, weight loss surgeon at Houston Methodist. "Exercise is, of course, an important component of weight loss. But, in most cases, it's not the predominant factor that leads to hitting a weight loss plateau."

So what is?

Why weight loss plateaus

When you're trying to lose weight but the scale won't budge, just know that weight loss is more complicated than your activity level. In fact, what you're eating is far more important.

"The weight loss equation is heavily skewed toward your dietary choices — not your activity level," explains Dr. Tariq. "You can eat or drink 400 calories in just a minute or two. To burn those 400 calories off, however, you would need to run (at a sprinting pace) for about 30 to 40 minutes. And this just isn't something the majority of people can do."

The reality — and brace yourself, it's a tough one — is that when weight loss stalls, it's usually because you're consuming more calories than you can feasibly expend. For the majority of people, exercise just can't make up for having a second slice of cake several times a month. And it can't make up for that large order of fries you inhale every week.

The key to avoiding a weight loss plateau is to make lasting changes to your diet — and letting time do the rest.

"This doesn't mean, however, that you can toss exercise by the wayside. You still have to work on both sides of the equation: Diet and exercise," says Dr. Tariq. "It's like when you're trying to save for a large purchase, such as a new car or a home. It takes spending less money as well as putting more aside. The same goes for weight loss. Eating less is a must, but so is getting plenty of exercise."

What to do when weight loss stalls

Like we said, losing weight is hard, and hitting a weight loss plateau is common. But don't let stalling numbers lead you to abandon your efforts completely.

Here are five ways Dr. Tariq recommends fighting back when your weight loss stalls:

1. Forget the crash diets

It's tempting to try one of those popular diets your friends (or the Internet) recommend, such as a juice cleanse, the keto diet, intermittent fasting or some other low-carb option. And while these diets lead to quick results, they may be doing more harm than good for your long-term weight loss success.

"We actually refer to these crash diets as "yo-yo diets," since they often result in a person dropping a lot of weight during the diet, only to regain it almost immediately afterwards. Then, he or she starts the diet again — and the yo-yo-like cycle continues," explains Dr. Tariq. "Crash diets simply aren't sustainable. In addition, these diets slow your metabolism and reduce lean body mass, making it harder to keep weight off long-term."

Because most crash diets leave you feeling hungry more frequently, Dr. Tariq says the more effective approach is to avoid crash diets altogether and learn how to better manage your hunger.

2. Control your hunger by making the right food choices

When it comes to sustaining a weight loss plan, controlling your hunger is crucial.

"Not all foods are created equal. Some foods are full of nutrients that help fill you up and keep you feeling full longer. Other foods are full of empty calories, contributing nothing towards your health or level of fullness," explains Dr. Tariq. "Most people hit a weight loss plateau or fall off of a weight loss plan because they aren't properly controlling hunger."

Here are Dr. Tariq's do's and don'ts of controlling your hunger:

• Do choose foods with high fiber and less sugar
• Do fill yourself up by eating plenty of non-starchy vegetables (green beans, broccoli, cauliflower, etc)
• Do swap sweet snacks or desserts for fresh fruits
• Do choose healthy fats, such as nuts or seeds, over saturated ones
• Don't eat foods full of added sugar
• Don't drink your calories
• Don't assume a food is healthy — check the label!
  
  

"Added sugar, in particular, can become an addiction and a huge contributor to experiencing a weight loss plateau," warns Dr. Tariq. "Added sugar provides no nutritional benefit and lights up the same areas of the brain that a drug does, albeit to a lesser extent. Plus, it's almost everywhere — even in foods you may think are healthy. It's really hard to lose weight if you're not avoiding added sugar as often as possible."

(Related: Are Your Taste Buds Sabotaging You From Eating Healthier?)

3. Track your diet and exercise

The weight loss equation really is an equation. Losing weight is all about the math surrounding the number of calories going in versus the number of calories coming out. A calorie deficit leads to weight loss. A calorie surplus leads to weight gain.

And while you can guess how many calories you eat per meal — just as you can guess how many calories you burn during a walk — tracking both your diet and exercise gives you a much more detailed picture of where you may be overdoing (or underdoing) it.

"There are plenty of free apps available for calorie monitoring, and fitness trackers can help you understand how effective your workouts are," says Dr. Tariq. "Diet-tracking apps are particularly useful for helping you understand which foods and meals are particularly calorie-dense or unhealthy — so you can learn what to avoid."

In addition, tracking your exercise can help you be more realistic about the right way to reward yourself for working out. To avoid stalling your weight loss goals, the 150 calories you burned on the elliptical shouldn't be rewarded with a 300-calorie coffee drink. In fact, tracking your exercise may illuminate that rewarding yourself with something other than food is actually the most effective strategy for weight loss.

4. Add strength training to your exercise routine

Cardio is the holy grail of weight loss exercises. But did you know that building muscle can help boost your overall metabolism?

"Cardio is an efficient way to expend calories as you're working out, but building muscle can help you burn calories even when you're not exercising," says Dr. Tariq. "Lean body mass, which includes muscle, uses energy throughout the day — and it gets this energy by burning calories. The more muscle you have, the more calories you will burn while at rest."

And you don't need to become a powerlifter or bodybuilder to add muscle, either. Even spending just 15 minutes doing simple bodyweight exercises or resistance-band workouts can help you build muscle. Don't drop your cardio altogether, but adding resistance training into your workout a few times a week can help you build lean muscle mass and boost your metabolism.

5. Shift your weight loss mindset

While we'd all love for weight loss to happen overnight, it just doesn't happen that way. Crash diets can provide short-term results, but long-term weight loss success requires making healthy choices more days than not and simply just being patient.

"A sustainable diet doesn't provide the degree of rapid weight loss that a crash diet can, but you have to accept this reality to be successful long-term," says Dr. Tariq. "When it comes to losing weight, 'slow and steady wins the race' really is true. A crash diet is a temporary fix, but you need an actual solution."

While it's slower than you may like, the right way to approach setting weight loss goals is to aim for about a pound of weight loss every two to three weeks. Over the course of the year, that can add up to 20 to 25 pounds of weight loss.

Ultimately, the key is to stop thinking of dietary changes as a temporary phase — because even after you lose the weight, the task of keeping it off begins and relies on many of the same principles. Weight loss and weight maintenance will always be challenging. But if you can shift your mindset and build lasting healthy eating behaviors, both become much more manageable.

(Related: What Is the Best Weight Loss Program?)