A new report published in The Lancet Diabetes & Endocrinology challenges the conventional definition of obesity, and urges a shift from the reliance on Body Mass Index (BMI) to a more nuanced approach. This is supported by over 50 global medical experts. The report also recommends splitting the term "obesity" into two categories: "Clinical obesity" and "Pre-clinical obesity". This aims to improve diagnosis and treatment for over a billion people worldwide living with obesity.

Clinically Obese

This applies to individuals whose obesity has progressed to a disease state, manifesting in organ damage, heart disease, type 2 diabetes, or other health complications. These individuals could also experience symptoms like breathlessness, joint pain, or impaired daily functioning. Treatment also involves medical interventions, including weight-loss medications or surgery.

Pre-Clinic Obese

Whereas the term "pre-clinic obese" refers to those who are overweight but not yet exhibiting health issues. While they may be at risk of developing obesity-related conditions, their organ function and overall health remain intact. What they need is preventive care, which includes dietary guidance, counselling, and regular monitoring to avoid and reduce future health risks.

What does the study say?

The study, led by Professor Francesco Rubino from King's College London emphasizes that obesity is not one-size-fits-all condition. This means it should rather be treated as a spectrum as some individuals maintain normal organ function despite being classified as obese. There are others who may face severe health complications too. However, the current method of calculating obesity based on BMI often leads to misdiagnosis or inadequate care.

The report also states that BMI, while is useful for analyzing population trends, is a flawed unit of measuring individual health. Therefore, there is a need to redefine obesity, and healthcare professionals can provide more precise care by distinguishing those who need immediate medical intervention and those who require preventive strategies.

Limitations of BMI, Why It Falls Short?

BMI is used to classify individuals as underweight, healthy weight, overweight, or obese based on their height and weight. It is calculated by dividing weight in kilograms by health in meters squared. However, there are reasons while it falls short.

•Muscle vs Fat: Athletes or muscular individuals often have high BMIs despite the low body fat

•Fat Distribution: BMI does not measure fat around the waist or organs, which could be more dangerous to one's health.

•Individual Health Variation: It also overlooks the specific health conditions such as heart diseases or diabetes, or any other, while evaluating a person's category in terms of weight.

ALSO READ: Is It Time To Say Goodbye To BMI?

Scope Of Study

By redefining obesity, the study could transform the approach to diagnosis and treatment. It can focus on individual health risks rather than BMI alone. Healthcare providers can also offer tailored care. This also will ensure hat weight-loss medications like Wegovy or Mounjaro are prescribed only to those who genuinely require it.

As per Professor Louise Baur from the University of Sydney, a Children's obesity expert said that this redefinition allows both adults and children to receive more appropriate care while reducing over-diagnosis and unnecessary treatments.

Short-term exposure to air pollution may increase the risk of hospitalisation for several serious health conditions, including cancers and mental disorders, according to a new landmark multicountry study published in The Lancet Planetary Health.

Researchers analysed 346.5 million hospitalisation records from 949 communities across six countries and territories, which included Australia, Brazil, Canada, Chile, New Zealand and Taiwan.

The study examined the relationship between short-term exposure to fine particulate matter (PM2.5) and hospital admissions between 2000 and 2019.

The findings revealed that every 10 micrograms per cubic metre (μg/m³) increase in PM2.5 concentration was associated with an 8% higher risk of hospitalisation from any cause. It was the strongest for malignant neoplasms, or cancers, followed by mental disorders.

The researchers also found that the increased risks associated with short-term exposure could persist for up to 21 days.

Hospital Admissions Related To Cancer And Mental Health Increased

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Among the disease categories examined, malignant neoplasms showed the strongest association with short-term PM2.5 exposure, with a 10.8% higher risk of hospitalisation for every 10 μg/m³ increase in particulate matter concentration.

It was followed by mental disorders, which showed a 10% higher risk. Other neoplasms were linked with a 9.6% increase, while nervous system diseases showed an 8.5% increase.

Respiratory diseases, that were commonly prevalent with air pollution, showed a 6.7% increase in hospitalisation risk.

These findings suggest that the health consequences of polluted air may not just be limited to lungs. They could affect people with a wide range of medical conditions.

However, the researchers assessed hospital admissions, not the occurrence of new diseases. Hence, they found that increases in PM2.5 exposure could increase the likelihood of hospitalisation among people affected by these conditions.

Decline In Hospitalisation Risks

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The researchers found that hospitalisation risks related to pollution were lower during 2010-2019 than in 2000-2009. Using the World Health Organization's daily PM2.5 guideline of 15 μg/m³ as a reference, the estimated proportion of hospitalisations due to exposure declined from 8.9% to 3.9% between the two decades.

Despite this improvement, the associations remained significant across all disease categories. The study had limitations, including substantial differences in effects across different countries and territories. Its findings also cannot automatically be generalised to regions that were not included, including India.

The researchers concluded that reducing PM2.5 exposure remains an important public health measure to lower hospitalisation risks. Cleaner transport, stricter industrial emission controls and lower reliance on polluting fuels could help limit exposure and the significant health burden that comes with it.

The researchers also said that the effects of short-term PM 2.5 exposure on hospital admissions could persist for up to 21 days after exposure.

Effects Of PM2.5

PM2.5 refers to fine particulate matter measuring 2.5 micrometres or less in diameter. These particles can come from vehicle exhaust, industrial emissions, construction activities, power generation and the burning of fuels and biomass.

Because of their small size, PM2.5 particles can penetrate deep into the lungs, with some components entering the bloodstream. Exposure can trigger inflammation and oxidative stress, potentially affecting multiple organs.

Despite the observation, the study does not prove that short-term exposure to air pollution increases the risk of serious diseases like cancer. Stronger air-quality monitoring, improved cancer registries and studies linking data with clinical results could help researchers assess whether pollutants are associated with specific cancer types.

Studies would also need to account for other risk factors and differences in exposure across populations.

India faces a substantial hepatitis C burden, with the World Health Organization (WHO) estimating that 5.5 million to 12 million people are living with chronic hepatitis C virus (HCV) infection.

Untreated chronic HCV infection can lead to liver scarring, cirrhosis and liver cancer. Could shortening treatment by four weeks help more patients access a cure?

A multi-center trial led by researchers from the Indian Council of Medical Research (ICMR) found that an eight-week course of a commonly used antiviral combination was as effective as the standard 12-week regimen in patients without cirrhosis. Published in The Lancet, the findings could have implications for treatment costs and access to care.

The treatment combines sofosbuvir (400 mg) and velpatasvir (100 mg), two direct-acting antivirals that target the hepatitis C virus.

What Did The Indian Trial Find?

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The RESOLVE trial, led by researchers from Sanjay Gandhi Postgraduate Institute of Medical Sciences (SGPGIMS), Lucknow, evaluated whether eight weeks of sofosbuvir and velpatasvir could match the effectiveness of the standard 12-week course.

The trial enrolled 880 patients without cirrhosis across five publicly funded hospitals in Lucknow, New Delhi and Varanasi. Half received the combination for eight weeks, while the other half received it for 12 weeks.

Among participants who completed treatment and follow-up, 98.8% in the eight-week group achieved a sustained virological response, compared with 99% in the 12-week group. This means the virus remained undetectable after treatment, indicating a cure.

The researchers found that the shorter regimen was non-inferior to the standard course, meaning it was not less effective beyond the trial's prespecified statistical margin.

The study also reported no drug-related serious adverse events or treatment discontinuations due to adverse events.

How Shorter Treatment Help Reduce Hepatitis C Burden In India?

Direct-acting antivirals transformed hepatitis C treatment nearly a decade ago, making it possible to cure most patients with relatively few side effects. However, treatment costs and access remain important considerations for large public health programmes.

A 12-week course of sofosbuvir and velpatasvir costs approximately ₹15,000. Shortening treatment by four weeks could save around ₹5,000 per patient.

If adopted for a population of 60 lakh people requiring treatment, the shorter regimen could potentially save ₹3,000 crore. However, these are projected savings, and the actual impact would depend on patient eligibility, treatment costs and adoption in clinical practice.

Who Can Receive The Shorter Treatment?

The findings apply to patients without cirrhosis, as the trial excluded those with the condition. Patients with cirrhosis may require different treatment approaches depending on the severity of their liver disease and other clinical factors.

The trial's results do not mean that everyone with hepatitis C can switch to an eight-week course. Further evaluation and changes to relevant clinical guidance may be needed before the shorter regimen becomes routine practice.

Patients should consult their treating physician before making any changes to their prescribed treatment.

How Does Hepatitis C Spread?

Hepatitis C can cause illness ranging from mild infection to serious, long-term liver disease. Although some acute infections resolve spontaneously, chronic infection can progress to cirrhosis and hepatocellular carcinoma, a type of liver cancer.

The virus can spread through infected blood, including via shared needles and unscreened blood transfusions.

Perinatal transmission is an important route of HCV acquisition in children. Early detection can help identify infected infants and ensure appropriate follow-up.

Colorectal cancer (CRC), a term encompassing cancer of the colon and rectum, is not only a growing burden in India, but a significant proportion of patients are now being diagnosed at a young age. While colorectal cancer is more common in older adults, Indian clinical studies have identified the phenomenon of young onset colorectal cancer (YO-CRC), typically diagnosed before the age of 50. An experts’ review on epidemiology of colorectal cancer with special emphasis on India, an article in 2025 was published in the Indian Journal of Gastroenterology. The review found that there has been an annual rise of 2-3% in the incidence of colorectal cancer over the past two decades.

In the area of Young Onset Colorectal Cancer, an editorial in 2024 in the South Asian Journal of Cancer noted that one quarter to one-third of colorectal cancer patients in India were below 40 years, and many were diagnosed at stage III or IV. Titled Clinicopathologic Profile and Treatment Outcomes of Colorectal Cancer in Young Adults, A Multicenter Study from India, an article published in JCO Global Oncology studied colorectal cancer among adolescents and young adults. The study revealed 62.70% had colon cancer and 37.30% rectal cancer, with 67% being aged 30-39 years and no significant gender predisposition, though females had a higher metastatic burden.

Why is colorectal cancer affecting younger Indians?

There is no single explanation. Researchers have studied factors like dietary changes, obesity, physical inactivity, altered metabolism, alcohol consumption, smoking, and environment as possible contributors. Increasing urbanisation and changing food habits could also be playing a role in India’s shifting colorectal cancer profile. But not all patients present with conventional risk factors, and in many patients, the causes remain unclear.

Genetic predispositions need special mention. Conditions such as Lynch syndrome and familial adenomatous polyposis (an inherited genetic condition that causes precancerous polyps to form in the large intestine) can raise the risk of colorectal cancer at a young age, but most young-onset cases are not explained by an inherited cancer syndrome.

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The problem of missed symptoms

One of the biggest problems in cancer treatment is delayed diagnosis. Because cancer is associated with older age, the symptoms in younger people may be mistaken for piles, constipation, diet-related problems or even irritable bowel syndrome. Rectal bleeding, persistent changes in bowel habits, unexplained weight loss, abdominal pain, iron-deficiency anaemia, persistent fatigue, or a feeling of incomplete bowel evacuation is usually dismissed as minor issues in younger people.

What should young Indians do?

Colonoscopy is not a solution that can be recommended for every young adult. Symptoms- and risk-based screening is a more reasonable approach. People with persistent symptoms, a strong family history of colorectal cancer, hereditary cancer syndromes, inflammatory bowel disease, or unexplained anaemia may require more intensive evaluation (including colonoscopy) if clinically indicated. This are high risk group, and they need regular screening lifelong. India’s colorectal cancer burden is rising, and younger patients are important segment of this burden.

The evidence available does not prove a nationwide explosion of colorectal cancer in under-50 age groups in India, but it does demonstrate an increasing overall incidence, a significant presence of young onset colorectal cancer, and frequent late presentation. If someone have a first degree relative with colon or rectal cancer like parents, ideally, they should have a colonoscopy done by the age of 45. For younger Indians, early recognition of warning signs may be one of the most critical steps for timely diagnosis and improved outcomes.

By Dr. Abhishek Gangopadhyay, Consultant - Surgical Gastroenterology, Surgical Oncology, Narayana RN Tagore Hospital, Mukundapur, Kolkata