BMI has been the benchmark in evaluating health and fitness for many years. The formula is quite simple: weight in kilograms divided by the square of height in meters. This would easily tell if one is underweight, within the healthy weight range, overweight, or obese. But with new research findings, scientists are now questioning its accuracy and usefulness as a total measure of body composition.

The report, published in The Lancet Diabetes & Endocrinology, has sparked a global conversation on rethinking BMI. Supported by more than 50 international medical experts, the report suggests classifying obesity into "clinical" and "pre-clinical" types for better diagnosis and treatment. The shift underscores a growing consensus: BMI alone may not tell the full story of your health.

While BMI is simple to calculate and universally accessible, it is far from perfect. It does not consider muscle mass, bone density, or fat distribution, leading to misleading conclusions in some cases. For example, athletes with a high muscle mass may be considered overweight, whereas individuals with normal BMI might carry unhealthy amounts of visceral fat.

A landmark study in JAMA Network Open studied more than 155,000 postmenopausal women and found that women with a normal BMI but a waist size over 35 inches were more likely to die from heart disease or cancer compared with their counterparts whose waists are smaller. That makes a great case for how BMI can be insufficient and fat distribution must be factored into account.

Not all body fat is equal. Subcutaneous fat, which lies just beneath the skin, is relatively harmless. The real health danger lies in visceral fat—fat that surrounds internal organs. Unlike subcutaneous fat, visceral fat is metabolically active, releasing stress hormones like cortisol and inflammatory substances that raise blood pressure, blood sugar, and cholesterol levels. These effects significantly increase the risk of conditions such as heart disease, type 2 diabetes, and certain cancers.

BMI Isn't Always the Best Measure of Body Composition — Here's What to Use Instead

Since BMI is not the most reliable measure, scientists and doctors have sought other means to measure body composition more accurately.

1. Waist Circumference

A simple tape measure can provide valuable insight into your health. Measure your waist at the level of your belly button, ensuring the tape is parallel to the ground. For women, a waist measurement under 35 inches is considered healthy, while for men, the goal is under 40 inches.

2. Waist-to-Hip Ratio

This is the ratio of your waist circumference to that of your hips. To calculate it, divide your waist measurement by your hip measurement. According to the National Center for Biotechnology Information, a ratio under 0.8 for women and 0.9 for men is considered healthy.

3. Body Roundness Index (BRI)

A newer method that seems to be receiving more attention involves the Body Roundness Index or BRI: height, weight, and girth are placed together to represent a more advanced view of what body composition says. Research presented in JAMA Network Open offers evidence that this BRI predicts mortality risk greater than BMI in some cases- a promising weapon for public health.

Also Read: Using BMI To Classify People As Obese Is Flawed Say Experts

Ways To Cut Off Unhealthy Fat

The good news is that visceral fat responds well to lifestyle changes. Here are three evidence-based strategies:

Time-Restricted Eating

Adopting an eating window of 12 hours—such as from 7 a.m. to 7 p.m.—can significantly reduce visceral fat, according to a study published in Nutrition Research Reviews. This approach not only helps control caloric intake but also reduces late-night snacking, a known risk factor for abdominal obesity.

Limit Alcohol Intake

Excessive alcohol consumption is associated with increased belly fat. A 2017 study published in Public Health Nutrition revealed that alcohol increases the levels of insulin and encourages the storage of fat in the abdominal area. Limiting alcohol to occasional indulgence helps avoid weight gain in this region.

High-Intensity Interval Training (HIIT)

HIIT involves repeated episodes of high-intensity exercise separated by periods of rest. A review in *Sports Medicine* concluded that HIIT is very effective in reducing visceral and total body fat. It can be noted that adding just 20 minutes of HIIT two times a week can make all the difference.

The reliance on BMI as a sole indicator of health is increasingly being challenged. While it remains a convenient screening tool, its limitations necessitate a broader approach that considers factors like fat distribution, waist circumference, and new metrics such as BRI.

In the simplest of words, health is multi-dimensional, and shifting perspectives from considering weight solely to broader measures of body composition will get people a much clearer understanding of where their health risks are so that they can take the action required for a better quality of life. Through adjustment to diet, exercise, or perhaps through innovative metrics like BRI, health is well within reach of the individual.

This dynamic conversation raises the point about personalized health screenings, which helps everyone get more relevant tools fitting their unique lives and circumstances. As body composition research is enhanced, so do the futures look brighter and brighter for the times of measurement when it comes to health.

Definition and diagnostic criteria of clinical obesity. The Lancet Diabetes & Endocrinology.

Association of Normal-Weight Central Obesity With All-Cause and Cause-Specific Mortality Among Postmenopausal Women. JAMA Netw Open. 2019

Waist-Hip Ratio. NIH.

Physiological responses to food intake throughout the day. Nutr Res Rev. 2014

Association between abdominal obesity and alcohol drinking pattern in normal-weight, middle-aged adults. Public Health Nutr. 2017

Physical fitness isn’t the only reason why astronauts exercise in space. Their daily workouts are a medical necessity meant to protect the heart, muscles and bones from the effects of microgravity.

New research based on 13 astronauts suggests that this strategy may be working.

Echocardiograms taken during six-month missions showed that the astronauts experienced mild changes in heart structure and function after entering microgravity, but these changes stabilised during the mission and returned to normal after they came back to Earth. The findings were published in Circulation.

The results are particularly important as space agencies prepare for longer missions, including journeys to Mars.

What Does Zero Gravity Do To The Heart?

On Earth, gravity constantly pulls blood and other body fluids towards the lower half of the body. In microgravity, that pull largely remains absent.

As a result, fluids shift towards the chest and head. The cardiovascular system initially receives more blood than it is accustomed to handling, but over time the body adapts by reducing blood volume. The heart also does not have to work against Earth's gravitational shift in the same way.

NASA says this can reduce cardiovascular function and contribute to problems like low blood pressure and dizziness when astronauts return to Earth.

Longer missions can make these changes more concerning. NASA notes that cardiovascular deconditioning can begin within days of entering a low-gravity environment.

Also read: Obesity Should Not Be Defined Solely By BMI: AIIMS Director Explains Fat Distribution & Metabolic Health

Astronauts Exercise For Around 2 Hours A Day

Astronauts aboard the International Space Station use a treadmill, stationary bicycle and resistance-training equipment.

NASA says crew members currently average around two hours of exercise per day, while another NASA health-care overview schedules astronauts for about 2.5 hours of daily exercise, including time for preparation and recovery.

The goal is not simply to burn calories. Aerobic exercise helps maintain cardiovascular fitness, while resistance training provides mechanical loading that the body no longer receives naturally from Earth's gravity.

NASA describes exercise as a vital practice for maintaining astronaut health and performance in low to zero gravity.

Also read: Are Gaming Chairs Actually Bad For Your Back? Why Cushioning, Posture And Long Sitting Matter

What Did The New Study Find?

The researchers went beyond measuring astronauts' heart rate and blood pressure. The crew members were trained to perform their own echocardiograms, allowing researchers on Earth to remotely guide them through ultrasound imaging of the heart while they were in space.

The scans showed that the heart adapted to microgravity, but the changes did not continue worsening throughout the six-month missions. After returning to Earth, the astronauts' cardiac structure and function returned to their earlier state.

Benjamin Levine, NASA cardiologist, said the findings were “really reassuring” for future Mars missions. He noted that when astronauts were exposed to simulated Martian gravity, equal to three-eighths of Earth's gravity, none showed a cardiovascular response more stressed than standing upright on Earth before the mission.

Essential For Longer Space Missions

A Mars mission would be far longer than a typical six-month stay aboard the ISS.

A planned mission could involve roughly six months travelling to Mars, an extended stay followed by another six-month journey home.

The heart therefore cannot simply rely on the possibility of recovering after returning to Earth.

Levine said future spacecraft will need exercise equipment capable of preserving “the entire spectrum of human adaptation to physical activity”, including the heart, skeletal muscles, bones, and even mental health.

One of the myths about chairs is that the more cushion you have, the better the support. However, comfort and support are not the same thing. A soft feeling chair may allow the body to sink into a position that is not in proper alignment of the spine, pelvis, neck and shoulders.

Gaming chairs often come with plush padding, deep seats, high backrests, and reclining mechanisms. These features may make the chair cozy for long gaming sessions. But this comfort can be at the expense of posture if the chair does not have enough lumbar support or the person is sitting in a slumped posture. The problem isn’t necessarily that a gaming chair is soft. The bigger issue is how the chair supports the body and how long the person sits in the same position.

How Long Hours Of Sitting Can Strain The Spine

When person sit for hours on end, the muscles that support the spine are working non-stop to maintain the correct posture. A backward roll of the pelvis and rounding of the lower back can put additional strain on the muscles and structures that surround the spine.

This can lead to pain, stiffness and discomfort in the lower back over time. Sometimes a firm office chair can provide a more stable base and help maintain a neutral sitting position. This does not mean that a hard chair is healthier than all gaming chairs, but that the right firmness and support might be better than too much padding that allows the body to sink.

The position of the lower back is especially important. The chair should curve to fit the natural curve of the lower back. Feet should be comfortably on the floor and hips and knees should be in a comfortable position. A bad sitting posture can also affect the neck and shoulders. If the monitor is placed too low, the head will move forward and downward. This may result in a stiff neck, shoulder pain and headaches over the following several hours.

Also read: Physiotherapy Day – Are Hourly Breaks Enough To Minimise Risks From Prolonged Sitting: Doctors Warn Office Workers

Why An Expensive Gaming Chair Cannot Fix Long Sitting

Another myth is that buying an expensive gaming chair automatically solves the problem of long sitting. A chair’s appropriateness is not dependent on the amount of cushioning. The height of the chair should correspond to the height of the person, the proportions of the body, the arrangement of the desk, and the daily activity.

More importantly, no chair can make long, uninterrupted sitting healthy. Those who work or game for several hours should get up regularly, walk a few minutes, stretch and change their sitting position.

Persistent back pain, numbness, tingling, weakness or pain traveling into the legs should not be simply put down to the chair and may require medical assessment. So, the healthiest chair may not be the softest or most expensive one. It’s the chair that gives good support, allows natural movement and doesn’t leave one in one position for too long.

By Dr. Mohit Muttha, Consultant Spine Surgeon, Manipal Hospital Kharadi

Millions of office workers spend eight to 10 hours at a desk on a regular basis. While sitting in one place may seem harmless, staying in the same position for prolonged periods can gradually affect muscles, joints, mobility and even metabolic health. Those are some of the reasons why experts call "sitting the new smoking".

Physiotherapists agree that the problem is not just 'bad posture'. The bigger concern is spending too much time without changing positions or moving your body.

HealthandMe spoke to Dr. Swapnil Keny, Consultant Orthopaedics & Joint Replacement, Fortis Hospital, Kalyan and Dr. Preeti Tare, Physiotherapist, P. D. Hinduja Hospital and Medical Research Centre, Khar about what office workers need to do to minimise the risks from sitting for prolonged periods.

Effects Of Prolonged Sitting

Dr. Swapnil Keny explains, "When sitting at a place becomes uninterrupted and constant posture, it builds pressure on the muscles of the neck, shoulders, back, and hips. The hip flexor muscles may become tight, and the glutes muscles along with other postural muscles may become inactive. The effects are not limited to the spine: prolonged sedentary behaviour is also associated with poorer metabolic and cardiovascular health."

Dr. Preeti Tare similarly points out that the earliest consequence may simply be a reduction in movement rather than an obvious injury.

Dr. Tare says, “The first change I notice is usually not an injury, but reduced movement. The hip and ankle joints spend hours in limited positions, while the glutes, deep abdominal muscles and upper-back muscles contribute less. The neck and shoulders compensate, especially when we lean towards a screen. Over time, this can reduce joint mobility, muscle endurance, and tolerance for everyday movement. Prolonged sitting can also affect blood circulation and metabolic health, so the impact goes well beyond back pain.”

Also read: That 3 PM Energy Crash May Be More Than Work Stress: Are You Missing Key Nutrients?

One Habit Experts Want Office Workers To Change

If there is one change office workers should make, both experts agree that it is to stop sitting continuously for hours.

“I would ask office workers to stop sitting continuously for hours. Set a reminder to stand up, walk a little or change position regularly. This simple habit reduces the time the same muscles and joints remain under static load. It is more useful than trying to maintain a “perfect” posture all day,” says Dr. Keny.

Dr. Tare recommends being even more proactive rather than waiting for discomfort to appear. She says do not wait for symptoms to appear. From time to time, make it a habit to get up and move around consciously.

These small changes, like walking to speak to a colleague instead of sending a message, standing during a phone call or taking the longer route to refill a water bottle, can help break up prolonged periods of inactivity and alleviate risks.

She says, “Break up sitting before your body starts complaining. Don’t wait for back pain or stiffness to remind you. Every 30–45 minutes, get up, walk to refill your water, speak to a colleague, or simply move around for a couple of minutes. From a physiotherapy perspective, frequent movement is important because tissues respond better to changing loads than to staying in one position for hours. The best posture is ultimately your next posture.”

Also read: World Physiotherapy Day - Beyond Surgery: Why Physiotherapy Decides How Well You Really Heal

Is An Hourly Break Really Enough?

One of the most important points office workers must remember is that moving around once every hour is bare minimum. It should also not become an excuse for remaining inactive for the rest of the day.

“Hourly breaks are a good starting point, but they are not a complete solution. The total amount of movement across the day matters too. A few minutes of walking every hour cannot fully replace regular exercise, walking during breaks and an active commute. Think of movement as a daily habit, not just a reminder on the computer,” says Dr. Keny.

Dr. Tare agrees that movement breaks and overall physical activity play different roles. In other words, the goal should be to reduce sedentary time while also building regular physical activity into the day.

“Both matter, but they serve different purposes. Short movement breaks interrupt the long, uninterrupted periods of sitting, while your overall daily activity builds strength, endurance and cardiovascular fitness. Someone who gets up every hour but remains inactive outside work is still largely sedentary. I encourage patients to think in layers: break up sitting during work, walk whenever possible, and include structured exercise during the week. No single movement break can compensate for an otherwise inactive day.”

Routine Movement For Desk Workers

Office workers do not necessarily need elaborate exercises between meetings. Instead, experts recommend weaving frequent movements throughout the existing workday.

“It is good practice to sit and stand alternatively and walk while on calls wherever feasible, throughout the day. Add a few gentle exercises such as shoulder rolls, neck movements, hip stretches and repeated sit-to-stand movements. Outside work, aim for regular walking and exercise. The idea is not to work out at your desk, but to maintain the movement of the body all the time,” says Dr. Keny.

Dr. Tare suggests a similar approach built around consistency rather than intensity. Desk workers need to stop treating movement as a separate activity.

Stand during calls, walk during breaks, change sitting positions, take regular short walks and incorporate simple movements throughout the workday.

“I prefer a routine that is realistic enough to follow every day. Alternate between sitting and standing, take a short walk every 30–45 minutes and use phone calls as opportunities to move. Twice or three times during the day, do a few sit-to-stands, shoulder movements, gentle spinal rotations and calf raises. Walk during your lunch break if possible. The aim isn't to turn your workstation into a gym; it is to prevent eight hours from becoming eight hours of almost no movement.”