"Why Am I Not Losing Weight?" 7 Weight Loss Mistakes You're Probably Making

You've hit another weight loss plateau while trying to lose weight , and it's time to face the truth: your workout plan and diet aren't working. You've been doing everything right… or so you thought. You meal prep on Sundays, you hit the gym, you even swapped your afternoon soda for sparkling water. But no matter what you try, the scale is not moving. You're left wondering, "Why am I not losing weight?"

The truth is, no matter how much time or effort you put into a weight loss plan, if you're making a few common mistakes, it just won't work. Weight loss isn't just about eating less and moving more; it's a complex interplay of biology, behavior, and environment. Many factors can prevent weight loss, and most of them are things the diet industry conveniently forgets to mention.

Let's talk about the most common exercise and diet mistakes people make, so you can finally understand why you're not losing weight and break through that frustrating plateau for good.

Table of Contents

Underestimating the Power of Energy Balance

One of the single biggest weight loss mistakes is misunderstanding (or completely underestimating) the power of energy balance. This is the non-negotiable of weight management, and if you get this wrong, nothing else matters.

Energy balance is the relationship between the energy you consume (calorie intake from food and drink) and the energy you expend (calories you burn through basic body functions and physical activity).

This is the fundamental principle that determines whether you're in a caloric deficit (losing weight), a caloric surplus (gaining weight), or at maintenance.

If you've ever said, "I work out and eat well but can't lose weight," this is almost certainly the mistake you're making.

Many people focus solely on eating "healthy" foods, which is a great start, but it can be a trap. Focusing only on the quality of food without considering the quantity ignores energy balance.

It is entirely possible to overeat nutritious foods like avocados, nuts, and olive oil and push yourself out of a caloric deficit. A calorie is a unit of energy, regardless of where it comes from.

To lose body fat, you must be in a caloric deficit, meaning you consume fewer calories than your body expends. When this happens, your body turns to its stored fat for energy, which leads to fat loss.

Another common pitfall is focusing only on exercise. If you've been working out consistently but not losing weight, you are still underestimating energy balance.

Exercise is an important part of maintaining or improving overall health. While it can't compensate for a diet that exceeds your calorie goals, it plays a key role in offsetting some health risks associated with weight loss and supporting your well-being.

A lot of people think they can use exercise to create a caloric deficit, but focusing solely on the calorie burn from exercise often misses the point. If you're not paying attention to how many calories you consume versus what you expend, you likely won't achieve the necessary deficit to lose weight effectively.

If you are not in a caloric deficit, you will not lose weight. Period. You need to be mindful of both the calories you consume and the calories you burn to make progress.

Not Eating Enough Protein

Most people don't just want to lose weight, they want to lose fat. And trust me, there's a big difference.

Weight loss is basically just the number on the scale going down. It could mean you've lost water, muscle mass, bone density, or fat (or maybe a mix of all of the above). Fat loss, though, is all about losing body fat while holding onto that lean body mass (muscle and bone density), which is super important for your long term health

If your goal is to feel stronger, healthier, and more energized, prioritizing fat loss is key! A common weight loss mistake is obsessing over the number on the scale instead of focusing on body composition. Building muscle not only makes it easier to maintain your weight long-term but also supports bone and joint health while playing a crucial role in your overall health.

This is where protein becomes your weight loss best friend.

Protein is the most significant nutrient for fat loss because it helps you preserve muscle mass while you're in a caloric deficit. When you begin to eat fewer calories, your body is primed to break down muscle mass for energy. Eating enough protein provides the building blocks (amino acids) your body needs to repair and maintain that muscle.

Protein isn't just great for keeping your muscles strong, it's also a superstar at keeping you satisfied between meals, keeping your energy up, and supporting your appetite. which means you might end up eating fewer calories with less effort.

Your weight loss program should prioritize high-protein foods. The current research suggests that people with fat loss goals should aim for 1.6-2.4g of protein per kg of body weight. 

Getting enough protein in your diet doesn't have to be complicated. Focus on basics like meat, poultry, fish, eggs, dairy, and legumes, these are all powerhouse protein sources. If you're on the go or need to add some more, throw some protein powder into a smoothie or shake. The key is to mix it up! Including a variety of proteins ensures you're covering all your bases with amino acids and other important nutrients.

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Skipping Meals to "Save" Calories

Many people skip meals, especially breakfast, thinking it's a clever hack to create a bigger caloric deficit while restricting calories . This is a huge weight loss mistake, and it almost always backfires. The problem with this "strategy" is that it messes with your body's natural hunger and energy cues.

Skipping meals can throw your energy balance completely off-kilter. When you skip a meal, your blood sugar can drop, putting unnecessary stress on your body. Then, when you finally do eat, you're often ravenously hungry. 

That primal hunger makes it much more difficult to make mindful, healthy choices. Instead, you're more likely to overeat and choose high-calorie, low-nutrient foods to get a quick energy spike. This pattern, repeated, can easily lead to weight gain, not loss.

If you've ever found yourself saying, “I'm eating less but not losing weight,” you might be eating too few calories at once and then accidentally overcompensating later, which completely ruins your caloric deficit.

The goal isn't to eat as few calories as possible. The goal is to eat as many calories as possible while still maintaining a slight, sustainable deficit. 

Instead of skipping meals, focus on eating smaller, balanced meals and snacks regularly throughout the day. This will help keep your energy levels stable, manage hunger, and prevent the impulsive overeating that can sabotage your weight loss efforts.

Not Drinking Enough Water

Water is absolutely essential for your overall health, but it's also a non-negotiable tool for effective fat loss. It's involved in nearly every bodily function, including digestion, nutrient absorption, circulation, and temperature regulation.

When it comes to fat loss, staying hydrated is crucial for metabolism. When you're in a caloric deficit and your body starts breaking down stored fat for energy—a process called lipolysis—it needs water to function efficiently. Dehydration can slow this process down, and hinder your weight loss progress.

Not drinking enough water is an incredibly common and easily fixable weight loss mistake. The Institute of Medicine (IOM) recommends about 91 ounces (2.7 liters) of fluids for women and 125 ounces (3.7 liters) for men per day, which includes water from all beverages and foods.

However, individual needs can vary based on your body size, activity level, and climate. If you find plain water boring, add some flavor with calorie-free options like sparkling water, unsweetened tea, or a squeeze of lemon. I find that keeping my water bottle with me at all times can serve as a constant reminder to stay hydrated!

Focusing Only on Exercise, Not Daily Movement

One of the most common fitness mistakes that prevent weight loss is focusing too much on your 60-minute gym session and ignoring the other 23 hours of your day. There's an important distinction between exercise and physical activity, and both are vital for overall health and supporting weight loss.

Exercise is structured, planned, and repetitive movement intended to improve physical fitness like running on a treadmill, lifting weights, or taking a spin class.

Physical activity, on the other hand, is any movement that contracts your muscles and expends energy. This includes exercise, but also everyday actions like walking to the store, taking the stairs, gardening, cleaning your house, or playing with your kids.

This non-exercise activity, often referred to as Non-Exercise Activity Thermogenesis (NEAT), plays a huge role in improving overall health and maintaining a healthy metabolism. While NEAT does contribute to your total energy expenditure, its benefits go far beyond just calorie burn. 

Regular movement throughout the day reduces the risks of chronic diseases, improves circulation, supports joint health, and helps manage stress, all essential for long-term weight loss and overall well-being.

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To optimize your overall physical activity, it's helpful to know the general guidelines. Experts recommend healthy adults aim for at least 150 minutes of moderate-intensity aerobic activity (like brisk walking or cycling) or 75 minutes of vigorous activity (like running) per week, combined with muscle-strengthening activities on two or more days a week. 

For weight loss, between 300 and 400 minutes of moderate intensity activity is recommended, but even beyond meeting these exercise guidelines, increasing your daily movement is key.

If you're spending long periods sitting, even a great workout won't fully counteract the effects of a sedentary lifestyle. Adding more activity into your day supports your body's health during weight loss and beyond. 

Start small: try parking farther away, taking the stairs instead of the elevator, using a walking pad while you work, or setting a timer to get up and stretch or walk every hour.

Sacrificing Sleep for Early Morning Workouts

Are your 5 a.m. gym sessions actually a weight loss mistake? They might be if they're cutting into your sleep. Sleep deprivation can wreak havoc on your body and completely derail your weight loss efforts in several ways.

First, a lack of sleep messes with the hormones that regulate hunger and appetite. It increases ghrelin (the "hunger hormone") and decreases leptin (the "satiety hormone"). This hormonal shift can lead to intense cravings, especially for high-calorie, sugary foods.

Second, sleep deprivation raises levels of the stress hormone cortisol. Chronically high cortisol is linked to increased fat storage, particularly around the midsection.

Third, when you're tired, you have less energy and willpower. This makes you more likely to skip your workout or be less physically active throughout the day, further reducing your calorie expenditure.

Most adults need 7-9 hours of quality sleep per night. Try your best to establish a consistent sleep schedule (even on weekends), create a dark and cool sleep environment, and avoid caffeine and screens for a few hours before bed. Getting enough rest is crucial for your overall health and a key component of a successful weight loss journey.

Trying to Lose Weight By Overhauling Everything at Once

I get it, you're excited to make a change and want to hit the ground running, so you take on your diet, exercise, sleep, and stress all at once. But trying to do everything can quickly lead to feeling overwhelmed and burned out. That "all-or-nothing" mindset can make sustainable weight loss feel impossible, especially when one small slip-up feels like failure. 

That's why I always encourage my clients to take it one step at a time. The secret to sustainable change is to focus on one small thing at a time. Making small, manageable behavior changes is far more effective than attempting a massive overhaul. 

When you make small changes, you build confidence with each success. These small wins (called self-efficacy!) are cumulative and build on each other, leading to significant results over time.

Instead of trying to lose weight by doing everything perfectly, pick ONE or two small adjustments to focus on for a few weeks at a time. Here are a few examples:

• Add a source of protein to one meal each day.

• Increase your daily step count by 500 steps.

• Go to bed 15 minutes earlier than usual.

• Drink one extra glass of water in the morning.

Focusing on small, consistent habits will make the weight loss process feel less daunting and more sustainable, helping you build a lifestyle that supports your long-term goals.

Your Next Steps

It doesn't matter how hard you work if your diet and exercise plan isn't built on the right foundation. If you're struggling to reach your weight loss goal, remember that many lifestyle factors contribute to your success. By avoiding these common weight loss mistakes, you can troubleshoot your approach and start making real progress.

Struggling to lose weight even though you're giving it your all? You're not alone—and sometimes, all you need is a fresh pair of eyes to figure out what's holding you back. That's where a health behavior coach comes in. Think of it like having a personal guide who gets to help you build healthy habits that stick. Sign up for Health Behavior coaching today and take the first step toward the healthier, happier version of you!