Obesity is a major global health challenge, affecting more than two billion adults, 35 million children under five, and 390 million children and adolescents worldwide. Central obesity – excess fat around the waist – fuels inflammation and raises the risk of diabetes, heart disease, and cancers, making waist circumference a better risk marker than BMI.
In India, the National Family Health Survey -5 (2019-2021) measured abdominal obesity for the first time, and revealed worrying trends. While only 23% of women qualified as obese by BMI, more than half in their 30s and 40s carried excess abdominal fat. In fact, 40% of women were abdominally obese compared to just 12% of men – showing how “normal” BMI often conceals hidden metabolic risk.
Sarcopenia
Body composition is more than just fat. It includes fat-free mass (bones, organs, water, and skeletal muscle), lean body mass, and fat mass. Of these, skeletal muscle is the engine of health – vital for mobility, metabolism, and strength.
Sarcopenia — the progressive loss of skeletal muscle mass, strength, and function — was once thought to be inevitable with age. Today, it is recognised as a clinical syndrome with profound consequences: frailty, falls, disability, and reduced quality of life. It may also result from chronic disease, malnutrition, or inactivity. Prevalence estimates range from 8-36% in those under 60 to 10-27% in older adults, with men generally more affected.
Sarcopenic obesity
When obesity and sarcopenia coexist, the result is sarcopenic obesity (SO) – a dangerous mix that worsens outcomes far more than either condition alone. Because fat masks muscle loss, SO is often missed, yet it is strongly linked with frailty, disability, cardiometabolic disease, and early death.
Muscle mass and strength peak between ages 30-50 before steadily declining. With over 1.4 billion people globally now above the age of 60, this age-related muscle loss is a growing public health issue. Muscle weakness reflects not just shrinking mass, but also declining quality, as fat infiltrates muscle and undermines its functional capacity.
Why muscle matters
Muscle is far more than mechanical tissue – it drives metabolism, regulates glucose, maintains energy balance, supports thermoregulation, and stores glycogen, protein, and fat. In obesity, fat accumulation inside muscles reduces both strength and quality, a process accelerated by ageing. Sarcopenia compounds these effects, worsening bone health, metabolic balance, and cardiovascular risk.
Protecting muscle during weight loss is therefore critical. Without it, people risk slipping into sarcopenic obesity – losing strength while retaining fat. Tools such as bioimpedance, DEXA, CT, MRI, and simple grip-strength or gait-speed tests can help detect risk early.
Obesity management
Obesity management includes pharmacological, surgical, and lifestyle-based approaches, often backed by behaviour change and public health policy. Yet across many treatments, one common side effect is overlooked – muscle loss.
Take pharmacological agents such as GLP-1 receptor agonists. In India, sales crossed ₹600 crore in just four months. While effective at reducing weight, they are linked with side effects including thyroid cancer, pancreatitis, gallbladder disease, depression, and suicidal behaviour – and importantly, with lean muscle loss. Research shows that one year after stopping therapy, participants regained two-thirds of their lost weight, alongside worsening metabolic health, implying much of the “weight loss” possibly came from muscle.
Bariatric surgery, though highly effective for fat loss, also strips away lean tissue – about 8 kg of fat-free mass and 3 kg of skeletal muscle in the first year. This decline not only weakens metabolism, but may also heighten appetite, increasing the risk of weight regain.
In contrast, lifestyle interventions – structured exercise and balanced nutrition – are safer, free from drug-related side effects, and sustainable long term.
Training and balance
At its core, obesity arises when calorie intake consistently exceeds energy expenditure. Effective management requires creating a calorie deficit, either by reducing intake, increasing activity, or both. Designing a diet modestly below daily energy needs supports sustainable fat loss without sacrificing lean tissue.
This is where resistance training plays a pivotal role. Combined with adequate protein intake (1- 2 gm/kg body weight/day), it preserves and builds muscle mass, sustains metabolism, and improves insulin sensitivity. Aerobic exercise complements it by boosting calorie burn and cardiovascular fitness. Together, they form the foundation for long-term obesity and metabolic risk management.
Resistance training does not require a gym or intimidating equipment. Bodyweight moves such as squats, lunges, push-ups, and planks can yield significant benefits. Strength training helps older adults maintain independence, supports women through pregnancy and menopause, benefits people with obesity, and improves outcomes in cancer recovery, diabetes, and heart disease.
Experts recommend the FITT principle (Frequency, Intensity, Time and Type: train 3-5 times a week for 30-60 minutes, with 6-8 key exercises performed in 10-15 repetitions, while allowing rest days for recovery. Even modest levels pay off: 30-60 minutes of muscle-strengthening activity per week is linked with 10-17% lower risk of cardiovascular disease, diabetes, certain cancers, and all-cause mortality. Resistance training also boosts mental health, improving memory, mood, and reducing anxiety and depression.
Building strength
Obesity and muscle loss are two sides of the same coin, and when they overlap as sarcopenic obesity, the risks multiply. India cannot afford to view health only through the lens of weight reduction. Protecting muscle through resistance training, smart nutrition, and recovery is the true shield against obesity, diabetes, heart disease, cancer, other non-communicable diseases, and frailty in old age. The message is clear: don’t just lose fat – build strength.
(Dr. Vid Karmarkar is chief scientific advisor with fitness company FITTR and Institute of Nutrition & Fitness Science. vid@fittr.com; Jitendra Chouksey is founder and CEO, FITTR jc@fittr.com)