A decrease in your size but not on the scale may be caused by losing fat while gaining muscle at the same time. Other causes may be temporary water retention or a weight loss plateau.

If you’re trying to lose weight, you might be using a scale to gauge your progress.

If so, it can be demotivating and upsetting to find that you’re not losing weight, even if you notice non-scale indicators like your clothes fitting more loosely or the need to tighten your belt.

This article looks at why you may be losing inches but not weight and explains what you can do about it.

If you’re losing inches but maintaining your weight and you regularly strength train, you may actually be losing fat and gaining muscle. The process of gaining muscle and losing fat at the same time is called body recomposition.

Most scales don’t differentiate between the amounts of body fat and muscle you have. For example, two people can weigh 150 pounds (68 kg) but have completely different body fat and muscle proportions.

In this example, the person with a higher ratio of muscle to body fat likely wears smaller clothes and has smaller body measurements because muscle is denser and takes up less room than body fat.

Strength training combined with a reduced-calorie and high protein diet favors muscle gain and fat loss, resulting in body recomposition (1, 2, 3).

The simultaneous gain in muscle and loss in fat can result in no weight loss or much slower weight loss over time.

This is one reason you shouldn’t rely solely on the scale to measure your progress when trying to lose weight. Besides, your ratio of muscle to fat is a better indicator of health than your body weight is.

While it’s not completely accurate, you can measure your body fat and muscle mass at home using a body fat scale (4).

A body fat scale is like a typical bathroom scale, but it estimates your body composition by sending a weak electrical signal through your body (5).

Summary

Your body weight doesn’t tell the whole story. You may be simultaneously building muscle and losing fat through a process called body recomposition.

Weight loss is not a linear process — it’s full of peaks and valleys.

Some days you may lose weight, some days you may gain weight, and some days your weight may not change at all. Part of the reason your weight fluctuates is because of fluid shifts or water retention.

You may retain water for a number of reasons, including:

  • Sodium. Eating a high sodium meal can cause your kidneys to retain water, resulting in increased weight (6).
  • Stress. Whether it comes from major life changes, relationship issues, or financial problems, stress can increase hormones that cause water retention (7).
  • Menstruation. Water retention and bloating are common during the menstrual cycle (8).
  • Creatine. While creatine effectively increases muscle strength and power, it can temporarily increase the amount of water in your muscle cells (9).
  • Medications. Certain medications, such as those for lowering blood pressure, controlling blood sugar, and managing inflammation, can cause fluid retention (10).

Water retention in these instances tends to be only temporary and go away on its own.

Summary

High sodium meals, stress, menstruation, creatine supplements, or certain medications can promote temporary fluid retention, which may lead you to believe you’re not losing weight.

Most weight loss tends to occur within the first 4–6 weeks of calorie restriction (11).

This weight loss tends to happen more rapidly in people who follow a low carbohydrate or keto diet than in those who follow a low fat diet due to the loss of stored carbohydrates and water (12).

Over time, weight loss may cause your metabolism to slow, significantly decreasing the rate at which you lose weight (13).

Your weight loss may even come to a plateau after months of restricting your calories. However, this decrease in metabolism is generally not significant enough to cause a plateau in your weight loss (14).

Instead, a weight loss plateau where you experience little to no weight loss tends to occur when you’re consuming more calories than you’re expending on a regular basis (14).

In other words, although you may think you’re consuming fewer calories than you burn each day, you might be consuming more.

Therefore, it can help to track your calories for at least 1 week to determine whether your calorie intake is too high based on your needs.

Remember that you’ll need to continuously adjust your calorie intake as you lose weight, based on factors like your age, gender, and activity level.

If you find that you’re maintaining a calorie deficit, other factors such as stress or a lack of sleep can increase hormones that can prevent weight loss and even promote weight gain (15, 16).

Summary

A weight loss plateau commonly occurs after several months of restricting your calories. For continuous weight loss, you may need to track your calories to ensure you’re maintaining a calorie deficit.

Weighing yourself is a good way to monitor your progress.

It can also reinforce the idea that factors like diet and exercise move you closer to your weight loss goal, while others, like a lack of sleep and excess stress, push you farther away.

Indeed, people who weigh themselves and engage in other self-monitoring behaviors, like tracking diet and exercise, seem to be more successful at both losing weight and maintaining the loss in the long term (17, 18, 19, 20).

Despite daily weight fluctuations that may occur due to factors such as water retention, most research suggests that daily weighing is more effective for weight loss and maintenance than weekly or monthly weighing (21, 22, 23, 24).

This may be because people who weigh themselves more often are more likely to engage in healthy behaviors like reading nutrition labels, eating whole grains, drinking less soda, and exercising vigorously (25).

While weighing yourself has not been strongly linked with poor body image, disordered eating, or anxiety, some people may experience these effects (26, 27).

If you find that daily or even weekly weighing leads to discouragement or obsessive behaviors, it may be better to monitor your progress in other ways.

In either case, remember that your weight is not always a reliable indicator of your health.

Summary

Daily and more frequent self-weighing has been associated with more weight loss and weight loss maintenance. Still, your weight is not the best indicator of your health.

There may be several reasons you’re losing inches but not weight.

You could be simultaneously gaining muscle and losing fat through body recomposition or experiencing temporary water retention.

You may have hit a weight loss plateau, meaning you may need to adjust your calories or better manage your stress and sleep schedule.

Weighing yourself daily or several times a week has been associated with increased weight loss and weight loss maintenance compared with less frequent weighing, but you shouldn’t rely on the scale alone to measure health.