Fat loss vs. weight loss: what’s the difference?

Fat loss vs. weight loss comes down to what your body is losing. Weight loss is any drop in body weight, whether from fat, muscle, or water, while fat loss is a reduction in body fat only. For many people, a helpful goal is to lose weight mainly from body fat while maintaining muscle. Knowing the difference can help you decide which to prioritize and how to track your progress.

For many people, the goal is not to choose between fat loss vs. weight loss. It is to lose weight primarily from body fat while maintaining muscle. That is because research suggests that maintaining — or building — muscle mass may support a faster metabolism, which can make it easier to manage your weight over time, while also providing other important health benefits.

Prioritize fat loss if you want to maintain muscle, which may support:

• The ability to walk, lift things, and generally move around

• A longer life overall

• A healthier brain and lower risk of dementia

Prioritize weight loss (at least initially) if too much body fat is affecting your health. Excess body fat can lead to negative health outcomes, such as:

• Higher cholesterol and blood sugar levels

• An increased risk of heart disease, diabetes, sleep problems, and certain cancers

• Joint problems and pain when walking around

• Lower emotional well-being and quality of life

When you are trying to lose weight, it is easy to develop tunnel vision over the numbers on the scale. But the scale does not paint the whole picture. It only shows how much you weigh, not how much of that comes from muscle, fat, or water.

Moreover, if you are exercising while losing weight, there may be weeks when your body weight does not change at all, even if you are losing fat. That is because muscle is denser than fat, so gaining muscle can offset the fat you lose on the scale. It is also why other tracking methods, such as body measurements, can be more insightful (and motivating) while losing weight.

Either way, the aim is to lose weight mainly from body fat while building or maintaining lean muscle mass, which can help you maintain a healthy weight.

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Fat loss describes a reduction in body fat. Weight loss describes a reduction in overall body weight, which can come from fat, muscle, and water. Put another way, all fat loss is weight loss, but not all weight loss is fat loss.

In reality, weight loss often involves a combination of fat, muscle, and water. The goal is to lose fat without losing too much lean muscle mass. This helps you reap the benefits of fat loss — such as a healthier heart and a lower risk of metabolic conditions — without the issues that can come with muscle loss.

Losing too much muscle mass may increase the risk of sarcopenia, a condition marked by a loss of muscle mass and strength that is more common with age. Sarcopenia has its own range of health problems, such as reduced function and mobility, which may increase the risk of falls, injury, and fatigue. Research suggests that muscle loss may also lower your resting metabolic rate, which can make it harder to lose weight or maintain your weight.

You can lose too much muscle mass when you do not actively incorporate strength training into your weight loss journey. It can also happen when you lose weight too quickly, such as through a crash diet.

In other words, body fat percentage and other measures of body composition can give a clearer picture of your progress than the number on the scale alone.

Weighing yourself on a traditional scale will not tell you whether you are losing fat, muscle, or water. There are other ways to find out how much body fat you have:

• Consider using a body fat scale. This can estimate how much fat and lean muscle mass your body contains. At-home body fat scales may not be as accurate as body fat assessments at a healthcare facility, but they can give you a general idea of your body fat percentage.

• Try a skinfold caliper. This instrument pinches specific areas of the skin to estimate body fat. When used correctly, it can measure body fat fairly accurately.

• Measure your waist circumference. Since higher levels of belly fat are linked to an increased risk of metabolic disease, it can help to know if your waist circumference is in a healthy range. The National Heart, Lung, and Blood Institute (NHLBI) says a waist circumference of more than 40 inches for men or 35 inches for women increases the risk of heart disease and type 2 diabetes. And certain populations, such as Asian Americans, have even stricter cutoffs because of their higher risk of metabolic diseases.

A 2018 review found that some of the most popular eating plans for weight loss — such as low-calorie, keto, and high-fiber — may cause weight and fat loss but can also reduce lean muscle mass. These eating plans were also more likely to produce short-term weight loss than long-term results.

On the other hand, eating plans high in protein may help you maintain muscle mass and lose body fat. According to research, consuming 1.4–2 grams of protein per kilogram of body weight per day is sufficient for most people who exercise to build and maintain muscle mass. A healthcare provider can help determine the right protein intake for you.

Still, following a high-protein eating plan may not be enough to support the right balance of fat and lean muscle mass. Experts suggest that the best way to reduce fat and maintain lean muscle mass may be to combine the following:

• Follow a high-protein, nutrient-dense eating plan.

• Reduce calorie intake.

• Adopt an exercise program that combines cardio and strength training.

In addition to getting enough protein, an eating plan that is low in sugar and simple carbohydrates and focuses on whole grains, fruits and vegetables, healthy fats, and lean proteins may support overall health.

Weight loss happens when the body is in a calorie deficit, meaning it uses more calories than it takes in, whether by eating less, burning more through exercise, or both. Cutting calories drastically or losing weight too quickly is generally not recommended.

The Centers for Disease Control and Prevention (CDC) notes that people who lose weight at a gradual, steady pace of about 1–2 pounds a week are more likely to keep the weight off. Losing weight faster than that can be unsustainable and may lead to muscle loss and rebound weight gain. Reducing your calorie intake by 500–750 calories per day, along with exercise, can support this healthy rate of weight loss.

Exercise can help you lose weight, and combining aerobic exercise with strength training may help maintain lean muscle mass. The NHLBI recommends 150–300 minutes of moderate-intensity or 75–150 minutes of vigorous-intensity aerobic activity per week. Experts recommend adding at least two days of resistance training per week.

Building muscle as you lose fat can change your body composition and offers several important health and wellness benefits.

People with overweight or obesity have a higher risk of cardiovascular and metabolic disease. Body mass index (BMI) measurements do not always account for a person’s body composition, meaning the ratio of fat to lean body mass. Research suggests that people with high levels of belly and body fat, not just higher BMIs, may be more likely to develop these diseases.

Losing excess fat while maintaining or gaining muscle becomes especially important with age, because muscle mass naturally declines over time. This can lower quality of life and may increase the risk of injury or falls. Experts encourage older adults to focus on getting enough protein and doing exercise routines that include strength training.

Building muscle may help protect against negative health outcomes and can support weight loss and weight management. That is because muscle tissue burns calories even when you are at rest. The more lean muscle mass you have, the higher your resting metabolic rate tends to be, according to research.

Fat loss and weight loss can affect health and metabolism in different ways. Here is what may happen as you start losing weight:

• Fat loss benefits: Retaining muscle and losing excess fat may lower your risk of type 2 diabetes, heart disease, metabolic syndrome, joint pain, and certain cancers.

• Muscle loss risks: Research suggests that calorie cuts without strength training may cause the body to break down muscle for energy. This may lower your resting metabolic rate and make long-term weight management harder, while also increasing your risk of sarcopenia.

• Appetite changes: When you start eating fewer calories, you may feel surges of hunger. Your metabolism may also slow down in response to the lower calorie intake, and levels of hunger and fullness hormones can stay changed for a year or longer after weight loss.

• Sleep changes: Initially, you may find it harder to sleep if you are experiencing hunger pains. Over time, losing weight and body fat may improve obstructive sleep apnea, making your sleep more restful.

• Mobility benefits: Losing weight may lessen the stress on your joints and reduce inflammation, which may ease joint pain. As you build muscle through exercise, you may feel stronger and more capable day to day, too.

Tracking both weight and body composition gives a fuller picture of progress. Try these methods to track your progress:

• Weigh yourself on a regular schedule. The scale shows how your total weight is changing, but not whether it is coming from fat, muscle, or water, so it works best alongside other measures.

• Take body measurements. Use a tape measure to record your waist circumference and waist-to-hip ratio, and log your progress in a journal or app. Both can give you an idea of how much belly fat you are losing, and research suggests they may be better than BMI at flagging heart attack risk.

• Take progress photos. Monthly photos can show how your body is changing shape. For an accurate comparison, take each photo from the same angle in the same clothes. You can also keep an old outfit from when you started losing weight to see how it fits over time.

• Get a dual-energy X-ray absorptiometry (DEXA) scan. This imaging test, done at a healthcare facility, is most often used to measure bone density but can also estimate how much fat and lean muscle mass your body contains.

• Use at-home body fat tools. At-home tools such as smart scales and skinfold calipers are less accurate than a DEXA scan, but they can still show how your body fat percentage is changing over time.

See if you qualify

Losing weight and improving your health is about more than the number on the scale. For many people, a helpful goal is to lose weight mainly from body fat while maintaining or building lean muscle mass.

• Losing excess body fat may lower the risk of metabolic conditions, heart disease, sleep problems, diabetes, certain cancers, and joint pain.

• Losing too much muscle may slow your metabolism and contribute to fatigue and mobility issues.

• To prioritize fat loss, aim for a nutritious, high-protein eating plan, a modest calorie reduction, and an exercise program that combines cardio and strength training.

• Body measurements, progress photos, smart scales, skinfold calipers, and DEXA scans can help track fat loss in ways the scale alone cannot.

• If lifestyle changes alone are not getting you where you want to be, a healthcare provider, such as on Ro, can talk with you about prescription weight loss medications and other medical weight loss support.