CLAIM:
Fat loss and weight loss are not the same.
FACT:
True. Weight loss and fat loss are not the same. Weight loss refers to a reduction in overall body weight, which can include fat, muscle, water, or glycogen, while fat loss specifically targets excess body fat, improving body composition, metabolic health, and long-term well-being. Experts suggest combining structured exercise, resistance training, adequate protein intake, and proper recovery to maximise fat loss while preserving muscle and maintaining overall health.
You’ve been trying too hard to lose weight, and then someone stops you mid-journey and says, “Fat loss is more important than weight loss.”
In a viral Instagram reel, fitness coach and influencer Priyank Mehta, who has 9.89 lakh followers, has reignited the debate around fitness goals and whether people should focus on losing weight or improving body composition and overall health instead.
The reel has sparked an online discussion on whether fitness should be measured by the scale or by overall strength, energy, and long-term well-being.
Is there a difference between fat loss and weight loss?
Weight loss and fat loss are often used interchangeably, but they represent very different physiological changes. Weight loss refers to a reduction in overall body weight, which can result from the loss of fat, muscle, water, glycogen, or even bone mineral content.
Fat loss, on the other hand, specifically means the reduction of body fat, and it is this change that improves metabolic health and physical well-being. The number on the weighing scale only shows how much total weight has been lost, not what part of it is fat. Losing fat is far more beneficial than losing muscle or water weight, as it positively alters body composition.
Body composition refers to the proportion of fat mass and lean mass in the body. Fat mass includes all the body’s stored fat, while lean mass or fat-free mass consists of muscles, bones, organs, and body water. A healthy body composition is characterised by a higher proportion of lean mass and lower fat mass. Understanding this difference is crucial because focusing only on the scale can give misleading results about actual health improvements.
What is the role of water and glycogen in weight fluctuations?
Water makes up around 50 to 60 per cent of a person’s total body weight. The term water weight refers to extra water that the body retains, which can change daily based on diet, hydration, and hormonal balance. However, drinking less water will not lead to fat loss. Drinking more water can help a person lose weight more effectively. Water also helps in transporting carbohydrates and proteins through the bloodstream for efficient energy use.
Healthily reducing water weight often involves lowering sodium intake, since excess sodium causes the body to retain water to maintain salt balance. Glycogen, the stored form of carbohydrates, also plays a key role in short-term weight changes. For every gram of glycogen stored, the body retains approximately three grams of water. This explains why people on low-carbohydrate diets experience rapid weight loss initially, as it is largely the result of glycogen and water depletion rather than fat reduction.
Why should fat loss be the goal?
Losing weight without considering body composition can be harmful. Rapid weight loss often results in the loss of muscle and water rather than fat. A 2018 review found that losing lean body mass can lead to reduced metabolism, fatigue, loss of neuromuscular function, emotional distress, and an increased risk of injury. The review also noted that metabolic decline caused by muscle loss often leads to the regaining of fat mass later on, worsening overall body composition.
“A comprehensive approach, integrating evidence-guided macronutrient and calorie intake, resistance exercise, and chromium picolinate, may be the most effective approach to preserving or increasing lean body mass while maximizing body fat mass reductions,” the review added.
How to distinguish fat loss from other weight loss?
Measuring fat loss is more complex than simply tracking changes on a weighing scale, as overall weight reduction can include fat, muscle, or water. Health professionals often use anthropometric devices to estimate body fat, but a 2021 review indicates that no single method is completely accurate. Many commonly used techniques can be expensive, complicated, or prone to measurement errors.
One common method is using body fat scales, which estimate body fat percentage through bioelectrical impedance. These scales can help individuals track changes in fat over time, although results may vary depending on hydration levels and other factors. Callipers are another tool used to measure fat thickness in specific areas of the body, such as the abdomen, but they require proper technique to yield reliable results. A tape measure can also track changes in body measurements to show where someone is losing inches, though it cannot determine whether the loss is from fat or lean tissue.
Body Mass Index, or BMI, is a widely recognised anthropometric measurement that classifies a person’s weight relative to their height. While a reduction in BMI may indicate fat loss, it does not differentiate between fat and lean mass, making it an imperfect tool for assessing true body composition. Similarly, measurements such as waist circumference or waist-to-hip ratio can provide insight into fat distribution, particularly around the midsection, but they should be used alongside other methods for a more accurate understanding of fat loss.
How to lose fat and maintain muscle?
The challenge in healthy weight management lies in losing fat without compromising muscle. A 2018 review comparing various diet plans, including low-carbohydrate, ketogenic, and high-fibre diets, found that although all could lead to weight loss, they also resulted in the loss of lean body mass.
In contrast, high-protein diets led to greater fat loss while preserving muscle mass. The same review suggested that dietary supplements such as chromium picolinate and green tea catechins may support lean mass retention, but the most effective strategy involves a combination of evidence-based nutrition and resistance exercise. Strength training, in particular, helps maintain muscle during calorie restriction and promotes better metabolic function.
What is the importance of age, exercise, and nutrition?
As people age, body composition naturally shifts. Fat mass increases while lean muscle and bone density decline. This process, known as sarcopenia, can lead to weakness, slower metabolism, and a higher risk of chronic diseases such as cardiovascular disorders, diabetes, and osteoporosis.
To counter these effects, older adults should engage in muscle-strengthening exercises at least twice a week, focusing on all major muscle groups, including the legs, back, chest, and arms.
Nutrition is equally important. Adequate protein intake is necessary to preserve muscle and promote fat loss. Research suggests that adults should consume 30 to 35 per cent of total daily calories from protein to maintain muscle mass and support fat reduction. Maintaining this balance of diet and physical activity also contributes to a positive mental state, helping individuals feel more energetic, motivated, and emotionally balanced throughout their weight management journey.
What do experts say about fat loss vs weight loss?
Dr Rajiv Kovil, Head of Diabetology and Weight Loss Expert at Zandra Healthcare, explains that during weight loss, the majority of the reduction comes from fat mass. “So whenever there is weight loss, the majority of the weight lost is fat. The lean mass, or fat-free mass, typically accounts for only about 10 to 15 per cent of the total weight lost,” he said.
He highlighted that clinical trials of anti-obesity medications, such as Surmount 3 and Surpass 3, have confirmed these findings. “When anti-obesity drugs are used, about 85 to 90 per cent of the total weight lost is fat, and only 10 to 11 per cent is skeletal muscle,” Dr Kovil noted.
He emphasised that observing someone’s appearance alone cannot accurately determine whether they have lost fat or muscle. “There is no way to tell just by looking. You need proper imaging like a DEXA scan or MRI to differentiate fat mass from skeletal muscle,” he explained. In addition to the medications mentioned, drugs such as tirzepatide and semaglutide have also undergone Phase 3 trials, with DEXA scans showing similar results- the majority of weight lost is fat, while skeletal muscle loss remains minimal.
Interestingly, Dr Kovil pointed out that despite some muscle loss, functional capacity and quality of life improve significantly. “Even with this small loss of skeletal muscle, a person’s functional capacity can increase two to three times. Studies using quality-of-life questionnaires have shown that patients feel stronger and more capable after losing weight, primarily due to fat reduction,” he said.
Currently, there is no approved therapy to treat sarcopenia associated with weight loss, though research is ongoing. “The closest potential therapy is bimagrumab, an IV injection being studied in combination with semaglutide. It has shown promise in improving muscle mass during weight loss, but the earliest it might be available is around 2029 to 2030,” Dr Kovil added.
He stressed the importance of exercise and nutrition in preserving muscle during weight loss. “Whether you are using anti-obesity drugs or following a stricter diet, you will lose some skeletal muscle unless you include core-strengthening and functional exercises. A high-protein diet, adequate hydration, at least 60 minutes of aerobic activity, and three to four resistance-training sessions per week can minimise muscle loss,” he explained.
Dr Kovil further highlighted the metabolic benefits of maintaining muscle mass. “When you convert muscle mass instead of white adipose tissue, insulin sensitivity improves, overall insulin resistance decreases, and inflammation markers related to insulin resistance improve as well. Muscle fibres require at least six to ten weeks of consistent exercise to show meaningful changes,” he concluded.
This story is done in collaboration with First Check, which is the health journalism vertical of DataLEADS.