Research Suggests Extra Weight May Benefit Older Adults

Older adults who carry extra weight often outlive peers with normal body mass indexes, according to new research that challenges decades of public health messaging.

The findings upend standard medical advice linking high body mass index numbers directly to early mortality. Past age 65, a higher weight is actually linked to greater longevity, health researcher Bryan Blissmer at the University of Rhode Island told nytimes.com.

That inverse relationship has surfaced in multiple large-scale investigations. Researchers analyzing nationally representative samples found that older men who were overweight or mildly obese faced half the mortality risk of peers with normal weight over a 14-year tracking period, nytimes.com reported.

“The picture isn’t the same once we get to older adults,” Blissmer told nytimes.com. Women in the study also showed a 27 percent lower mortality rate when categorized as overweight.

Weighing Longevity Against Body Mass Index

Body mass index calculates a ratio using height and weight measurements. Standard guidelines categorize normal weight between 18.5 and 24.9, while measurements from 25 to 29.9 indicate overweight status.

For an American man over 65 standing 5 feet 8 inches tall, normal weight spans 122 to 164 pounds. An overweight classification for that same height ranges from over 164 up to 197 pounds.

Average height for women over 65 sits at 5 feet 3 inches. Normal weight limits for those women run from 105 to 141 pounds, while overweight measures go from 141 to 169 pounds.

Extreme obesity involving a body mass index above 40 still elevates mortality risks. However, the highest risk overall belongs to older individuals who fall into the underweight category with a body mass index below 18.5.

Heavier Weight Provides Survival Advantages During Medical Hardship

The survival advantage associated with heavier weight grows stronger as people age and face severe medical conditions. Nephrologist and epidemiologist Kamyar Kalantar-Zadeh at Harbor-U.C.L.A. Medical Center studied patients undergoing dialysis for kidney disease.

“When we face hardship, including people with kidney disease who need dialysis to survive, being overweight or obese can help,” Kalantar-Zadeh told nytimes.com.

Similar survival benefits emerged among heavier seniors suffering from coronary artery disease and heart failure. Researchers documented comparable advantages for older patients diagnosed with specific cancers, including colon cancer.

“The older you are, the survival advantage of being obese increases,” Kalantar-Zadeh told nytimes.com.

Scientists debate the exact mechanisms behind this phenomenon. Additional nutritional reserves may help aging bodies survive acute health setbacks. Alternatively, researchers point to survivorship bias, noting that individuals susceptible to weight-related illnesses often pass away earlier in life.

Abdominal Fat Increases Mortality Risks Despite Body Mass Index

Relying solely on body mass index provides an incomplete picture because the metric fails to track muscle mass, bone density, or fat distribution. Geriatrician and researcher Sei Lee at the University of California, San Francisco, emphasized these limitations to nytimes.com.

Abdominal fat storage creates distinct health hazards regardless of overall body mass index scores. The University of Rhode Island study linked higher waist circumferences—exceeding 35 inches for women or 40 inches for men—to higher mortality rates.

“The fat stored in your abdomen is more biologically active” than fat deposits located in hips, chest, or buttocks, Blissmer told nytimes.com. “It has a greater association with insulin resistance, inflammation, elevated cholesterol and Type 2 diabetes.”

The Lancet Commission recommends incorporating waist measurements alongside body mass index calculations when evaluating patient health risks.

Societal Pressures Influence How Older Adults View Their Weight

Many older adults continue battling societal pressures regarding physical appearance despite the reassuring data. Tucson resident Glenna Ganster, 72, recently ramped up her daily exercise routine and baking habits after struggling to maintain weight loss from intermittent fasting.

“I don’t want to look like my mother or my grandmother,” Ganster told nytimes.com.

Her physician discouraged her interest in popular GLP-1 weight loss medications, noting her body mass index of 25.7 indicates a healthy size. When Ganster learned about the longevity research, her reaction was immediate.

“You made my day,” Ganster told nytimes.com.

Doctors advise patients to focus on functional health markers rather than scale numbers. Lee urged older adults to maintain healthy diets and physical activity routines.

“As a doctor, one thing that always makes me sit up straight is when an older adult’s weight is changing substantially in either direction,” Lee told nytimes.com.

Common Questions About Weight in Later Life

Does a higher body mass index protect against all health conditions after age 65?

Additionally, excess abdominal fat measured by a waist circumference over 35 inches for women or 40 inches for men increases the likelihood of insulin resistance and Type 2 diabetes, according to research published in the Journal of the American Geriatrics Society.

Why is body mass index considered an incomplete measurement for seniors?

Body mass index relies exclusively on height and weight ratios without distinguishing between muscle mass, bone density, and fat distribution. Researchers at the University of California, San Francisco, note that it fails to capture critical health variables necessary for evaluating older adults.

What weight category faces the highest mortality risk in older age?

The greatest mortality risk among older populations occurs in individuals who are underweight, defined as having a body mass index below 18.5, according to data cited by nytimes.com.

Health Metrics Beyond The Scale

“One reason I’m looking forward to the next round of publications from that University of Rhode Island team is that they’ll look beyond longevity alone and measure the association of BMI with health, disability and quality of life,” said Paula Span, The New Old Age columnist.

More on this story: Obesity May Lower Dementia Death Risk