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.

Breast cancer remains one of the most common and fatal cancers among women worldwide, and early detection is proven to play a crucial role in improving outcomes. While mammography remains the most effective screening tool, knowing when to start and how often to get screened can be confusing.

The changing medical guidelines, as with the new screening guidelines from the American College of Physicians (ACP), can also leave women confused about when to start mammograms and how often to repeat them. HealthandMe spoke to experts to understand the correct timing.

So, What Do The ACP Guidelines Say?

The new guidance statement developed by ACP's Clinical Guidelines Committee urged mammography screening once every two years in asymptomatic, average-risk adult females, instead of the annual recommendation.

The ACP guidelines further state that all average-risk females ages 50 to 74 must undergo biennial mammography. It added that women aged 75 years or older with asymptomatic and average-risk can also discuss stopping routine screening with their doctor.

In sharp contrast, the United States Preventive Services Task Force (USPSTF) urges starting annual screening at age 40 to save lives.

What You Should Follow

“Some cancer societies like the American Cancer Society say biennial, while NCCN says annually. We prefer annually starting at age 40 till the woman is in good health, as biennial screening may delay early diagnosis in some cases,” Dr. Ashwani Kumar Sharma, Vice Chairman - Manipal Comprehensive Cancer Centre and Onco Robotic Surgeries, Manipal Hospitals, Gurugram, told HealthandMe.

NCCN, or the National Comprehensive Cancer Network, is an alliance of 34 cancer centers in the US.

Dr. Sharma added that a practical and balanced approach would be to do biennial mammography from 40 to 50 years of age and annual mammography after 50 years of age for maximum benefit.

What Are Mammograms?

A mammogram is a low-dose X-ray that captures detailed images of breast tissue, capable of identifying cancers before any physical symptoms appear.

In women with a BRCA1 or BRCA2 gene mutation who are referred to as "high risk" or with a history of radiation to the chest between ages 10 and 30, screening may start as early as age 30 and include annual breast MRIs alongside mammograms.

Mammograms: What Do India’s Guidelines Say?

Breast cancer in India is usually diagnosed at an advanced stage due to poor health awareness. But of late, there has been an increase in awareness, and more and more women are reporting in their earlier stages with a breast lump.

“Sometimes even this is too late. Breast cancer screening would help us diagnose this disease at an even earlier stage to help increase the chances of a cure from this deadly but treatable disease with the help of simple tests,” Dr Abhijit Kotabagi, Senior Consultant, Department of Surgical Oncology, Yatharth Hospital, Noida, told HealthandMe.

“I would endorse screening and women’s health awareness in our Indian population for women above 40 years after discussion of the pros and cons of screening with a clinician,” he added.

The Indian Council of Medical Research (ICMR) and other health organizations recommend the following guidelines:

1. Women Aged 30-40 Years

• Clinical Breast Examination (CBE) every 1-3 years by a doctor.
• Self-Breast Examination (SBE) every month to check for lumps or changes.

2. Women Aged 40-50 Years

• Annual Clinical Breast Examination (CBE).
• Mammogram (X-ray of the breast) every 2 years if advised by a doctor.

3. Women Above 50 Years

• Mammogram every 2 years (or as recommended by a doctor).
• Continue monthly self-exams and yearly clinical exams.

India is in the peak of summer, with heatwave conditions affecting several parts of the country. The India Meteorological Department (IMD) has predicted that these extreme heat conditions will continue over the next few days, especially across North and Central India.

According to IMD's latest bulletin, heat wave conditions are likely in isolated pockets of Bihar, Haryana-Chandigarh-Delhi, Punjab, East Rajasthan, Vidarbha, Chhattisgarh, and Jharkhand.

The IMD has also forecast a yellow alert for heatwave conditions at isolated places in Delhi from today, with maximum temperatures expected to climb between 41 °C and 44 °C through April 24. The state government has issued guidelines for all schools, focusing on hydration and safety measures.

As temperatures rise, health experts highlighted the disproportionate burden of heat on women and the related physical, social, and financial effects. Studies show women often have higher heat-related mortality rates and suffer from increased fatigue, dehydration, and reproductive health issues.

Women typically face higher risks during heatwaves than men due to

• physiological factors (higher body fat, lower sweat rate),
• hormonal changes (menopause, pregnancy),
• social roles.

How Heatwaves Affect Women Differently

Heat stress is known to interfere with the endocrine system, which disrupts hormonal balance. This means that severe heat can cause delay or interrupt menstrual cycles, causing heavier or more painful periods, and, in severe cases, absence of menstruation. Women with conditions like PCOS or endometriosis face compounded stress.

"Many women report feeling unusually tired, irritable, or drained during heat waves, and hormones can play a role," Dr. Tripti Raheja, Director - Obstetrics & Gynecology at the CK Birla Hospital (R), Delhi, told HealthandMe.

Women are more likely to feel this during certain hormonal phases, such as menstruation, PMS, pregnancy, perimenopause, or menopause.

“Women’s core temperatures rise after ovulation. That, combined with a higher surface area-to-mass ratio, means they absorb heat more quickly,” Mike Tipton, professor and leading expert in applied physiology at the University of Portsmouth, was quoted as saying to Thisdaylive.com.

Women in perimenopause or menopause may experience hot flashes, night sweats, and sleep disturbances, making heat waves exhausting.

Also read:Heatwave Hassles: What Body Odour Could Say About Your Health

Iron deficiency or heavy bleeding can also lower energy levels, and extreme heat may worsen weakness.

Pregnant women naturally have higher metabolic demands, so dehydration and fatigue can set in faster.

Without sufficient hydration, blood flow to the placenta might be reduced, potentially harming the baby. Heat exhaustion in pregnancy can cause early labor or stillbirth. Thyroid disorders and PCOS can also contribute to fatigue and reduced overall energy levels, Dr. Raheja said.

"Long exposure to high temperatures can disrupt the balance between hormones such as estrogen, progesterone, and thyroid hormones, which regulate energy, mood, and metabolism," Dr. Sakshi Goel, Senior Consultant Obstetrics & Gynecology at Rainbow Children's Hospital, Delhi, told HealthandMe.

Dehydration further worsens this by affecting circulation and temperature control, leading to exhaustion, headaches, and dizziness.

Moreover, sleep disturbances from hot nights can impair melatonin production and disrupt overall hormonal rhythms. This leads to poor recovery and low energy the next day.

How Women Can Protect Their Health From Heatwaves

Read: Excessive Energy Drinks Damaging Young Adults’ Livers, Experts Warn

Understanding how heat affects hormonal health lets women take steps to manage fatigue and maintain overall well-being during extreme weather.

To cope better, the experts suggested prioritizing hydration and including ORS when needed.

Dr. Goel noted that even mild fluid loss can hurt circulation and lower the body’s ability to regulate temperature. This can lead to exhaustion, headaches, and dizziness. Other preventive measures include:

• Avoiding long sun exposure during peak hours.
• Eating lighter, balanced meals and avoid stepping out during peak afternoon heat.
• Wearing breathable clothing and ensure adequate sleep in a cool environment.
• Gentle movements, such as walking or stretching, can improve circulation and mood.
• If fatigue is severe, persistent, or associated with dizziness, palpitations, irregular periods, or excessive weakness, it is important to seek medical evaluation rather than dismissing it as just the weather.

In this hot summer period, with rising temperatures, those working outdoors are among the groups most susceptible to developing health problems, especially those related to kidney health. Construction workers, delivery workers, traffic officers, farmers, and sanitation workers all work for long periods outdoors in the sun, which adds continual strain on their bodies. While heat exhaustion and dehydration have been discussed frequently, a less visible but very significant concern is the increasing risk of kidney damage.

In an interview with Health and Me, Dr Anupam Roy, Additional Director – Nephrology and Kidney Transplant, Aakash Healthcare Multi-Speciality Hospital, Dwarka, spoke about the silent impact of the heatwave on outdoor workers.

With continued exposure to heat, there is increased sweating, which results in the insensible loss of a considerable amount of fluid and electrolytes from the body. If this is not matched by adequate fluid replacement, dehydration will set in. Dehydration reduces the amount of blood circulating throughout the body’s systems; therefore, the amount of blood flowing to vital organs, including the kidneys, will be diminished. As a result, the ability to filter waste from the body and maintain an adequate fluid balance is impaired. Reduced circulation to the kidneys will eventually impair their function altogether, thus leading to a greater likelihood of the worker developing an acute kidney injury (AKI).

How does a heatwave affect the kidneys?

There is a continuum of challenges that arise when kidney damage occurs as a result of internal heat stress due to poor hydration. The earliest signs are usually fatigue, dizziness, muscle weakness and/or cramps, or reduced urine production. Many people mistakenly believe these symptoms are due to their duties in hot conditions, or they dismiss them as something that will go away with time. By the time they begin to recognise an increase in the severity of their symptoms (for example, a lack of strength or confusion), significant damage to the kidneys may have already developed. Because of this delay in recognising kidney damage, the ability to treat and manage the condition becomes much more difficult.

Chronic dehydration

Chronic dehydration and heat stress also have additional long-term effects on the kidneys. Research has shown that prolonged exposure to heat is linked to a higher incidence of kidney stones and urinary infections in those frequently exposed to high temperatures. Both individuals with traditional risk factors for kidney disease (for example, diabetes or hypertension) and those without such risk factors can develop chronic kidney disease. Many agricultural and manual labour workers have been shown to develop this condition in hot climates.

Working and living conditions can further exacerbate the risk of developing chronic kidney disease due to dehydration and heat-related illness. Limited or no access to clean drinking water, a lack of restroom or food breaks, and the expectation to maintain high productivity can reduce workers’ ability to hydrate themselves appropriately. Additionally, many workers may resort to medications such as pain relievers due to discomfort. When such medications are consumed alongside dehydration, they can aggravate kidney damage.

How to protect your kidneys amid a heatwave?

To help prevent heat-related damage to the kidneys, awareness and practical measures are essential. Staying hydrated at all times is the most important step, and workers should drink sufficient water even when not thirsty. Employers and agencies must ensure that all employees have easy access to safe drinking water on-site, along with regular breaks to rest in shaded or cool areas. Furthermore, workers should wear lightweight, breathable clothing and have access to shade, hats, and sunscreen to reduce exposure to extreme heat.

Several simple steps can help protect this workforce from the hidden effects of extreme heat. These include avoiding work during the hottest parts of the day, rotating job responsibilities, providing education about the signs of heat-related illnesses, and conducting regular health assessments to monitor kidney health so that any issues are detected early.