When was the last time you measured your waistline? If you assume that BMI is the only number to focus on when it comes to your health, think twice. New research has revealed a shocking revelation—your waist circumference might be a far better predictor of men's cancer risk than BMI.

The study finds that for each 4-inch increase in waist size, a man's risk of cancer increases by a staggering 25%. Meanwhile, BMI, commonly regarded as the gold standard for assessing obesity, raises cancer risk by only 19% for the same weight gain. So, if you've been dismissing that pesky belly fat, it's time to take notice.

But why is your waistline so important? The reason is visceral fat—the hidden, deep fat that accumulates around your organs. Unlike other body fat, visceral fat is a stealthy troublemaker, causing inflammation, insulin resistance, and abnormal blood fat levels—all of which combine to create a cancer-perfect storm.

Obesity has been associated with an increased risk of numerous health conditions, including cancer, for decades. The research, though, indicates that a specific measure of the body—waist circumference—may be an even more reliable forecaster of cancer risk in men than the more frequently employed Body Mass Index (BMI). This finding emphasizes the need to pay particular attention to the distribution of fat and not merely to the weight of the body.

BMI has been the go-to measure for years for gauging health risks related to obesity. New research, though, that appears in The Journal of the National Cancer Institute indicates that waist measurement is a better predictor of cancer risk in men. According to the research, four more inches (10 cm) around the waist will add 25% to a man's cancer risk. Conversely, a 3.7 kg/m² rise in BMI (from a BMI of 24 to 27.7) increased cancer risk by only 19%.

Why is waist circumference a better predictor, then? Unlike BMI, which measures weight relative to height, waist circumference actually measures abdominal fat—specifically, visceral fat. This type of fat encircles internal organs and is also linked to higher levels of inflammation, insulin resistance, and abnormal blood lipids, all of which are factors in cancer growth. BMI, however, does not measure fat distribution, so two individuals with the same BMI can have very different levels of health risk depending on where fat is deposited on their bodies.

Why Men Are at Higher Risk?

Interestingly, the research identified a significant difference between men and women when it came to waist circumference and cancer risk. Although waist circumference and BMI were linked with obesity-related cancers in women, the relationship was weaker than for men. An increase of 12 cm (4.7 inches) in waist size or a 4.3 rise in BMI (from 24 to 28.3) raised the cancer risk in women by just 13%—a much lower percentage than for men.

Experts credit this difference to the way that fat is stored in the body. Men are more likely to carry fat around the abdomen, especially as visceral fat, which is more metabolically active and associated with cancer-producing biological alterations. Women, by contrast, store fat in peripheral sites such as the hips and thighs, where it is less likely to drive systemic inflammation and metabolic disturbances.

A possible reason is that men tend to depot fat more in the visceral regions, whereas women tend to carry more subcutaneous and peripheral fat," wrote the researchers. "This may render waist circumference a more robust risk factor for cancer in men and account for why waist circumference provides additional risk information beyond BMI in men but not women."

Cancer Types Most Linked to Abdominal Fat

The research used the International Agency for Research on Cancer (IARC) data to define obesity-related cancers. These cancers are esophageal (adenocarcinoma), gastric (cardia), colorectal, rectal, liver, gallbladder, pancreatic, renal, and thyroid cancers, and multiple myeloma and meningioma. In men, abdominal obesity is especially significant in raising the risk of these cancers through high levels of insulin and markers of inflammation.

For women, the research proposes that both waist circumference and hip circumference may give a more accurate estimate of visceral fat and cancer risk. "Adding hip circumference to risk models could strengthen the link between waist circumference and cancer, especially in women," researchers observed.

What This Means for Men's Health and Cancer Prevention?

With these results, doctors advise men to be more mindful of their waistline than only their BMI. Waist size is an easy method to gauge health risk, and its maintenance through lifestyle changes might be the key to cancer prevention.

How To Reduce Cancer Risk In Men?

Track Your Waist Size: Regularly measure your waist circumference and try to keep it in a healthy range (below 40 inches for men, according to medical advice).

Eat a Balanced Diet: A diet containing high fiber, lean protein, and healthy fats can assist in limiting visceral fat gain.

Exercise Consistently: Regular exercise with a combination of aerobic and strength training will help maintain a healthy waistline.

Control Stress and Sleep: Persistent stress and inadequate sleep tend to cause weight gain, especially in the midsection of the body.

Regular Health Screenings: Early identification of cancer risk factors through regular screening can greatly enhance long-term health status.

Beyond lung cancers, air pollution fine particulate matter (PM2.5) is increasing mortality for breast as well as liver cancers, according to a global study led by the Union for International Cancer Control (UICC), including researchers from the Indian Council of Medical Research (ICMR).

The important study showed that long-term exposure to PM2.5 increases the overall risk of developing cancer and the chances of dying from it compared with those living in cleaner environments.

For every 10 micrograms per cubic meter (µg/m³) increase in PM2.5 exposure, the overall risk of cancers increases by more than 11 per cent. At the same time, the risk of death also increases by more than 12 per cent for every 10 µg/m³ increase in PM2.5 exposure.

The researchers argued that while other common risk factors like tobacco and alcohol are being targeted with notable progress, air pollution is silently eroding the gains being made.

“We have made huge strides in reducing deaths from cancer, but polluted air is silently undermining that progress. It is a risk people cannot opt out of, and one that disproportionately affects women, children, and people living in poverty,” Cary Adams, CEO, UICC.

“The cancer community continues to make progress in addressing other major risk factors, including tobacco use, alcohol consumption, and viral, bacterial, or parasitic infections such as HPV and HBV that cause cervical and liver cancers. It is increasingly clear that air pollution must also be recognized as a major and preventable factor that increases the risk of developing cancer and of dying from the disease,” added Dr Elisabete Weiderpass, Director, IARC.

Risks of PM2.5: Beyond Lung Cancer

The study, based on data from 42 meta-analyses and systematic reviews published between 2019 and 2024, showed significantly strong associations for liver, colorectal, and breast cancers.

As per recent data from the International Agency for Research on Cancer (IARC), PM₂.₅ exposure contributes to 434,000 lung cancers per year, accounting for more than a quarter of preventable lung cancers in women and nearly one in six in men.

In addition to lung cancer risk, the study noted that the rising levels of PM2.5 are associated with

• a 32 per cent higher incidence of liver cancer
• an 18 per cent increase in the odds of developing colorectal cancer.

• a 12 per cent higher overall risk of dying from cancer,
• a 20 per cent higher risk of death from breast cancer,
• a 14 per cent from liver cancer,
• a 12 per cent from lung cancer.

Who Is At A Higher Risk

According to the researchers, people living in low- and middle-income countries bear the greatest overall burden. These countries frequently lack the resources to reduce pollution at source or to provide timely access to cancer prevention, diagnosis, and treatment.

The challenge is compounded by the projected rise in global cancer cases, expected to increase from 20 million in 2022 to 35 million by 2050. People at risk include:

• Women and children, particularly in settings where solid fuels are used for cooking and heating.
• Women exposed to household air pollution face a 69 per cent higher risk of lung cancer, alongside increased risks of cervical cancer.
• Outdoor workers and communities living near industrial facilities are also at heightened risk, with exposure often concentrated in economically deprived areas.

What Actions Are Required?

The researchers underscored that the evidence presented in the report is already sufficient to justify decisive action to reduce exposure to polluted air. They called upon policymakers to make required changes across energy, transport, industry, and urban planning to reduce the risk of cancer from air pollution.

The study urged the need for properly implementing effective interventions that are well-established. These include:

• Stronger emissions standards and enforcing the WHO air quality Standards
• A transition to clean energy and clean cooking
• Improved urban design by investing more in green infrastructure
• Expanded air-quality monitoring in High-Risk Areas
• Update cancer control plans.

During the summer, it is important to stay hydrated, but for kidney patients, excessive intake of fluids is just as dangerous as not drinking enough. Most people are encouraged to drink extra fluids during hot weather; however, patients with chronic kidney disease (CKD) and those on dialysis must exercise greater control over their daily hydration and fluid intake because their bodies cannot effectively excrete excess fluids, leading to potential complications.

What is overhydration?

Dr Anupam Roy, Additional Director – Nephrology and Kidney Transplant at Aakash Healthcare Multi-Specialty Hospital, Dwarka, said, “Overhydration occurs when the body retains more fluid than it is able to eliminate. For kidney patients, overhydration typically leads to fluid overload as a result of excessive fluid accumulation in the body. Early signs of fluid overload may include swelling in the feet, ankles, and/or face. If not treated, fluid may continue to build up and cause the lungs to fill with fluid, resulting in shortness of breath and difficulty lying down. If left untreated, gaseous exchange in the lungs will be impaired, and the patient will require immediate medical treatment for pulmonary oedema (a life-threatening complication).”

What happens when you are overhydrated?

The effect of excess fluid on the heart and blood pressure is considered a significant concern. Excess fluid results in additional strain on the cardiovascular system, leading to high blood pressure. This extra workload may also increase the risk of serious complications (e.g., heart failure) for individuals who already have hypertension or heart disease. Dialysis patients are at particular risk of developing complications since they rely on regularly scheduled treatments to remove excess fluid. Excessive fluid consumption between dialysis sessions may complicate and increase the discomfort associated with removing excess fluid during dialysis.

How does overhydration affect kidney disease patients?

Overhydration may also cause an imbalance in electrolytes, such as sodium. Consuming a large amount of water without adequate intake of electrolytes could dilute sodium in the bloodstream, resulting in hyponatraemia. Symptoms of hyponatremia vary from mild (nausea and headaches) to severe (confusion, seizures, and, in extreme cases, coma). This condition can potentially be life-threatening for kidney disease patients, who often have difficulty maintaining an optimal balance of electrolytes.

Many people forget that they can obtain fluids from certain foods and drinks, such as soup, yogurt, watermelon, and tea or juice. In the summertime, people tend to consume these types of foods and drinks more often, which can cause them to exceed the recommended daily fluid intake. Many also believe that drinking extra water will flush toxins out of their system; however, when the kidneys are not functioning properly, excess fluids can be difficult to remove from the body.

How much water should kidney patients drink?

Dr Roy said that proper hydration for someone with kidney disease needs to be planned carefully. The amount of fluid a person can consume depends on their stage of kidney disease, urine output, and whether they are on dialysis. Some simple strategies can help maintain proper hydration: use small cups for drinks, consume fluids throughout the day rather than all at once, avoid foods high in salt (as these increase thirst), and track daily fluid intake.

The main reason for drinking fluids is to ensure the right amount is consumed; therefore, the most important aspect of hydration is maintaining balance. Maintaining this balance can help prevent complications and allow individuals to remain as healthy as possible. When kidney patients understand their hydration needs and receive proper guidance during the summer, they can avoid causing further harm by placing additional strain on their bodies.

The U-WIN (Universal Immunization Win) platform has been transformative and has helped India tackle the concerning burden of zero-dose children, said Dr NK Arora, an immunization expert and member of the National Technical Advisory Group on Immunisation in India (NTAGI).

In an exclusive conversation with HealthandMe during World Immunization Week 2026, Dr Arora, Executive Director of The INCLEN Trust International, traced the journey of the U-WIN portal and explained how it has strengthened vaccine uptake in the country.

U-WIN is a digital platform and app to help people find vaccination centers near their residences, manage vaccination appointments at health facilities, and maintain vaccination records.

Dr Arora noted that the U-WIN portal created a digital ecosystem that played a critical role in registration, appointment scheduling, vaccine tracking, and real-time monitoring.

The Origin Of U-WIN

U-Win was launched in October 2024 and is available in 12 languages, including English.

Dr Arora, also the chair of the COVID-19 and HPV vaccine working group, shared that during the deadly COVID pandemic in 2020—around July—it became very clear that to vaccinate 140 crore people, some kind of IT platform is needed that will track individuals who had been vaccinated, especially when they needed their second dose, and later, booster doses.

“Everything started somewhere around July 2020, and by January 2021, we had the Co-WIN platform. By mid-April, things were streamlined. The platform gives us a long list of individuals who have been vaccinated. It also helps to know who has been left out of the vaccination.

“It is like a registry of human beings who are getting immunized. And we could send reminders, we could send certificates, and we can also tell the individual when to get their second and third dose,” the expert said.

He noted that as COVID became less intense toward the end of 2021, serious discussions began on using the same platform for routine immunization. This is where the concept of U-WIN came in 2022. It has now been piloted and is gradually being used.

U-WIN: Closing the Gap For Missed and Zero-Dose Children

The UWIN now has the mechanism to ensure that immunization is completed for everyone who registers. One user can register up to 10 people in one mobile number, including citizens/guardians, pregnant women, infants (0-1 years), children (1-7 years), and adolescents (7-19 years).

“The key issue is that tracking provides two or three important inputs. First, it ensures that everyone is getting vaccinated and that it is not dependent on memory. There is a proper record—whether a person or child has received vaccines and what their current status is, including whether the schedule is complete,” Dr Arora said.

“Second, one of the main reasons for missing or delaying the next dose was that mothers often did not remember. Fathers contributed very little to this process, but they also became involved because of the reminder system,” he added.

Another important role of U-WIN is tackling the so-called zero-dose children—those who have never been vaccinated.

“About 4–5 per cent of our eligible population falls into this category, meaning they have not received even the first pentavalent dose. On the face of it, 4–5 per cent may not seem like a huge problem. But when we look at the absolute numbers—out of 26 million—it translates into a very large number, which we cannot afford to miss. So tracking helps identify these children through the micro-plan system”.

U-WIN Enables Life-course Immunization

Also read: World Immunization Week: Vaccines Are Like Insurance, They’re Safe—Take Them, Says Dr NK Arora

“When a child is vaccinated, we know when boosters are due—at one and a half years, then at five years. But none of us remembers this. Even among well-informed parents, this is often forgotten. This system helps address that gap,” Dr. Arora said.

Further, when the same individual becomes eligible for vaccines like HPV—typically between 9 and 14 years—there is again a gap that needs to be addressed.

Certification is another benefit, as it creates a documented process, particularly for programs like oral polio vaccination.

Dr. Arora highlighted that in case of any future pandemic-like situation that requires repeated vaccinations, “we have a mechanism in place”.

“This IT platform has truly transformed the system. There is also a lot of discussion about using similar platforms for TB patients, pregnant women, and other flagship programs like non-communicable diseases. So, for India, digitalisation is at its best when we talk about U-WIN.”