9 Reasons You’re Not Losing Weight When Dieting and Exercising

5 minutes read

Few things are more frustrating than hitting a wall on your weight loss journey, especially if you’re watching your calories and exercising regularly. While things like genes and medical conditions all play a role in your weight, there are other factors within your control that may be affecting your ability to lose weight. In this article, we’ll walk through nine reasons you may not have considered and what to do about them.

graphic depicting relationship between insulin resistance and weight loss

1. You have insulin resistance

Insulin resistance, a condition that affects 4 out of 10 non-diabetic Americans, occurs when your cells stop responding properly to the hormone insulin. Insulin plays a key role in allowing glucose (from the food you eat) to enter your cells, where it is then transformed into adenosine triphosphate (energy). Insulin resistance and weight gain exist in a positively reinforcing loop. Put another way, having insulin resistance can lead to additional fat storage, which in turn makes you more insulin-resistant, and so on [1]. Not only does insulin resistance make it more challenging to maintain a healthy weight, but studies show that people with insulin resistance tend to lose more muscle mass and less fat mass, which continues to exacerbate the problem [2].

Here’s what you can do:

Reversing insulin resistance requires a two-part solution: (1) improving insulin sensitivity and (2) stabilizing your glucose levels.

The best way to improve insulin sensitivity is by exercising regularly — current guidelines suggest that 75-150 minutes of resistance training/aerobic exercise per week (depending on intensity level), spread out amongst ~3 sessions, can help improve metabolic health. Research has found that even just walking 50-70 minutes 3 times per week for 12 weeks resulted in weight loss and improved insulin sensitivity [3]. Other factors like getting good sleep and managing stress levels are also important for insulin sensitivity.

To stabilize your glucose levels, eat a diet that’s centered around fiber-rich, nutrient-dense whole foods. This means eating more colorful vegetables, whole grains, lean proteins, and healthy fats, as well as minimizing refined sugar and ultra-processed foods.

2. You’re too focused on the number on the scale

It’s easy to become fixated on the digits flashing on the scale, but your body weight isn’t the most accurate metric for tracking weight loss. Regular exercise, especially resistance training, can lead to significant changes in your body composition that a scale can’t capture. When you lift weights, for example, you’ll gain lean muscle mass and appear more toned — your clothes will fit better, and you may notice slimming, especially around your waistline. That’s because muscle takes up less space than fat (it’s more dense). That said, a pound of muscle still weighs the same as a pound of fat [4]. This means that you could be losing fat and gaining muscle at the same time, leading to aesthetic differences you can notice in a mirror without a dramatic shift in your actual body weight.

Here’s what you can do:

Instead of basing your sense of achievement on the scale, try other ways of tracking your progress. This could mean noting improvements in strength — like lifting more weight at the gym or performing more reps — or simply noting how much better you feel in your daily activities. You may also want to consider weekly progress photos taken at a consistent location and time of day, or tracking inches lost off of your waist rather than pounds lost.

3. You’re focusing on calories rather than nutrient density

When you’re trying to manage your weight, it’s easy to get caught up in counting calories. But the “calories in, calories out” model of weight loss, where you consume fewer calories than you expend, doesn’t account for a key part of the equation: nutrient density. Think of it like this: if your body is a car, calories are the fuel that keeps it running. But the quality of the fuel makes a difference in whether or not your car runs smoothly.

In other words, what you eat affects your glucose levels, hormones, and other systems in your body that regulate satiety, appetite, and energy levels — all of which can affect how much you eat and your ability to lose weight. A 400-calorie meal that’s made up of refined carbohydrates (bread, sugar, etc.) and minimal fiber may spike your glucose levels, leading to a crash that triggers cravings and, over time, makes your body more insulin-resistant and prone to weight gain. On the other hand, a 400-calorie meal that consists of fiber-rich vegetables, lean protein, and minimal carbs will promote stable glucose levels and keep you full for longer, potentially helping with weight loss.

Here’s what you can do:

Instead of counting calories, prioritize whole foods that are nutrient-dense, like fruits, vegetables, whole grains, healthy fats, and lean proteins. Make sure you’re getting enough fiber, and avoid added sugar and processed foods. Since everyone has a different biological makeup, consider using a tool like a continuous glucose monitor to see how your unique body responds to different foods and adjust your diet accordingly.

graphic depicting different macronutrients

4. You’re not eating enough protein and fat

Protein and fat play a crucial role in our body’s metabolism, the process that converts what we eat into energy. Both have a slower digestion rate compared to carbohydrates — eating a meal that contains proteins and fats results in a more gradual release of glucose into your bloodstream, preventing a spike. These spikes and crashes not only affect your energy levels and mood but, over time, can strain your body’s ability to manage glucose effectively, leading to insulin resistance and weight gain.

Of the three macronutrients, protein is also the most satiating. In other words, it fills you up more than carbs and fats, which can help prevent overeating. It’s also a key part of building muscle mass, which burns more calories than fat and absorbs more glucose from the bloodstream, improving insulin sensitivity [5]. Similarly, fat can support satiety as well as help your body better absorb important vitamins and minerals. Some fats, like omega-3s, can even help improve insulin sensitivity, reduce inflammation, and lower triglyceride levels [6].

Here’s what you can do:

Incorporating a good balance of protein and healthy fats in your meals can support sustained energy levels, reduce cravings, and help your body regulate blood sugar more effectively. Lean meats (chicken, turkey), fish (salmon, tuna, sardines), eggs, extra-virgin olive oil, nuts, seeds, and avocados are excellent sources of protein and fat. For a complete list, check out our Mediterranean Diet Grocery List.

5. You’re eating your carbs at the wrong time

Carbs are essential fuel for your body and cells, but eating them at the wrong time may add to the challenge of losing weight. Research suggests that we tend to be more insulin sensitive earlier in the day. In the evening, when our bodies are slowing down and preparing for rest, we are more insulin resistant [7, 8]. By eating carbs when your body is insulin resistant, like at night, you increase the risk of blood sugar spikes, which over time can lead to chronic insulin resistance, which can contribute to weight gain. So if you’re skipping breakfast and snacking or eating meals late in the evening, this may be making it harder for you to lose weight.

Here’s what you can do:

Even if you’re not an early riser, try eating your carbs earlier in the day rather than at dinner and lunch. You may see better blood glucose levels, fewer cravings, and stable energy levels. In the evening, work with your body by moving your typical dinnertime an hour earlier (or more!) and see how your glucose responds. Lower-carb, lighter fare in the evenings supports restful sleep and improved insulin sensitivity.

6. You have leptin resistance

The hormones leptin and ghrelin regulate hunger levels. Ghrelin is the hunger hormone, telling you when to eat, and leptin is the fullness hormone, telling you when to stop eating [9]. If you continuously overeat past fullness, your body may become resistant to leptin, making it hard to stop eating when you are full.

Here’s what you can do:

To combat leptin resistance, be conscious of portion sizes and eat high-fiber foods that fill you up without being highly energy-dense. Research shows that time-restricted eating may be a good strategy to combat leptin resistance so you can lose weight effectively.

7. You’re not getting enough sleep

Sleep is a crucial component of your metabolic health. When you sleep, your body reduces glucose utilization, and your metabolism slows down so you can rest and recover from the activity of the day. However, when you are not getting enough sleep or your sleep quality is poor, your glucose regulation during the day can be impacted. Studies show that glucose tolerance during the day decreased by 30% in people who slept 4-6 hours a night, and having a widely variable bedtime and wake time can increase the risk of high glucose, insulin resistance, and weight gain [10, 11]. Lack of sleep can also cause you to crave more sugar and refined carbohydrates, which leads to blood sugar spikes and consumption of excess empty calories. All of these things can cause you to gain and retain weight, even if you are exercising and eating right.

Here’s what you can do:

To fix this, aim to get 7-9 hours of sleep a night, and try to get up each morning and go to sleep each night consistently within a 30-minute window of time. You can try some of these tips to improve your sleep hygiene and get a better night’s rest.

8. You’re overestimating how much exercise you are doing

Don’t misunderstand: exercise is one of the best ways to improve and maintain your glucose levels, insulin sensitivity, and weight. But relying on exercise as your only way to lose weight might not be sufficient – especially if you exercise once during the day and then remain sedentary for the rest of the day. Being sedentary throughout the day, especially after meals, can lead to poor insulin action, meaning higher glucose levels and fluctuation throughout the day.

Here’s what you can do:

Try to incorporate short bursts of exercise throughout the day to keep glucose levels stable and insulin sensitivity high and to prevent weight gain. For example, try taking a walk after a meal, going up and down the stairs a few times, or just doing squats at your desk. Research shows that as little as 2 minutes of walking after a meal can help curb a glucose spike [12]. Staying active throughout the day in addition to regular exercise may be the edge you need to maintain healthy glucose levels and achieve stable weight loss.

9. You’re chronically stressed

We are all familiar with stress occasionally, but feeling stressed constantly over time can contribute to problems with losing weight. Chronic stress increases the release of cortisol, the stress hormone. While some degree of stress is healthy, chronic stress over time can cause a number of problems, like high blood sugar, overeating, fatigue, and insulin resistance.

Here’s what you can do:

Notice when you are stressed and try a short breathing exercise, a quick walk, or some time in nature. All of these can reduce stress levels by slowing heart rate and lowering glucose levels.

Key takeaways

Reverse insulin resistance by improving insulin sensitivity via consistent exercise and stabilizing your glucose levels via a metabolically healthy diet.
Instead of focusing too much on the scale numbers, track your weight loss journey with other metrics, such as progress pictures or the number of reps you’re able to do at the gym.
Instead of counting calories, focus on nutrient-dense whole foods that don’t spike your glucose levels. Use a CGM to track your body’s response to specific foods and make the right choices for you.
Eat lean proteins and healthy fats with your meals to improve satiety and stabilize glucose levels.
Eat carbs earlier in the day, when your body is more insulin-sensitive, and skip carb-heavy snacks or meals late at night.
Eat high-fiber foods and practice time-restricted eating to overcome leptin resistance, which may be dysregulating your appetite.
Get 7-9 hours of sleep a night at consistent times.
Stay active throughout the day, in addition to your usual exercise routine, to keep your glucose levels in check.
Manage chronic stress with breathing exercises, a quick walk, or time in nature.

References:

Written by: Emily Johnson, MSc RD

Reviewed by: Dr. Vimal Ramjee, MD, FACC

Table of Contents

1. You have insulin resistance
2. You’re too focused on the number on the scale
3. You’re focusing on calories rather than nutrient density
4. You’re not eating enough protein and fat
5. You’re eating your carbs at the wrong time
6. You have leptin resistance
7. You’re not getting enough sleep
8. You’re overestimating how much exercise you are doing
9. You’re chronically stressed
Key takeaways