Millions of people enter later life carrying an extra 10 to 15 pounds, weight they’ve gained after having children, developing joint problems, becoming less active, or making meals the center of their social lives.

Should they lose this modest extra weight to optimize their health? This question has come to the fore with a new category of diabetes and weight loss drugs giving people hope they can shed excess pounds.

For years, experts have debated what to advise older adults in this situation. On one hand, weight gain is associated with the accumulation of fat. And that can have serious adverse health consequences, contributing to heart disease, diabetes, arthritis, and a host of other medical conditions.

On the other hand, numerous studies suggest that carrying some extra weight can sometimes be protective in later life. For people who fall, fat can serve as padding, guarding against fractures. And for people who become seriously ill with conditions such as cancer or advanced kidney disease, that padding can be a source of energy, helping them tolerate demanding therapies.

Of course, it depends on how heavy someone is to begin with. People who are already obese (with a body mass index of 30 or over) and who put on extra pounds are at greater risk than those who weigh less. And rapid weight gain in later life is always a cause for concern.

Making sense of scientific evidence and expert opinion surrounding weight issues in older adults isn’t easy. Here’s what I learned from reviewing dozens of studies and talking with nearly two dozen obesity physicians and researchers.

Our bodies change with age. As we grow older, our body composition changes. We lose muscle mass — a process that starts in our 30s and accelerates in our 60s and beyond — and gain fat. This is true even when our weight remains constant.

Also, less fat accumulates under the skin while more is distributed within the middle of the body. This abdominal fat is associated with inflammation and insulin resistance and a higher risk of cardiovascular disease, diabetes, and stroke, among other medical conditions.

“The distribution of fat plays a major role in determining how deleterious added weight in the form of fat is,” said Mitchell Lazar, director of the Institute for Diabetes, Obesity and Metabolism at the University of Pennsylvania’s Perelman School of Medicine. “It’s visceral [abdominal] fat [around the waist], rather than peripheral fat [in the hips and buttocks] that we’re really concerned about.”

Activity levels diminish with age. Also, with advancing age, people tend to become less active. When older adults maintain the same eating habits (energy intake) while cutting back on activity (energy expenditure), they’re going to gain weight.

According to the Centers for Disease Control and Prevention, 27% of 65- to 74-year-olds are physically inactive outside of work; that rises to 35% for people 75 or older. For older adults, the health agency recommends at least 150 minutes a week of moderately intense activity, such as brisk walking, as well as muscle-strengthening activities such as lifting weights at least twice weekly. Only 27% to 44% of older adults meet these guidelines, according to various surveys.

Concerns about muscle mass. Experts are more concerned about a lack of activity in older adults who are overweight or mildly obese (a body mass index in the low 30s) than about weight loss. With minimal or no activity, muscle mass deteriorates and strength decreases, which “raises the risk of developing a disability or a functional impairment” that can interfere with independence, said John Batsis, an obesity researcher and associate professor of medicine at the University of North Carolina School of Medicine in Chapel Hill.

Weight loss contributes to inadequate muscle mass insofar as muscle is lost along with fat. For every pound shed, 25% comes from muscle and 75% from fat, on average.

Since older adults have less muscle to begin with, “if they want to lose weight, they need to be willing at the same time to increase physical activity.” said Anne Newman, director of the Center for Aging and Population Health at the University of Pittsburgh School of Public Health.

Ideal body weight may be higher. Epidemiologic research suggests that the ideal body mass index (BMI) might be higher for older adults than younger adults. (BMI is a measure of a person’s weight, in kilograms or pounds, divided by the square of their height, in meters or feet.)

One large, well-regarded study found that older adults at either end of the BMI spectrum — those with low BMIs (under 22) and those with high BMIs (over 33) — were at greater risk of dying earlier than those with BMIs in the middle range (22 to 32.9).

Older adults with the lowest risk of earlier deaths had BMIs of 27 to 27.9. According to World Health Organization standards, this falls in the “overweight” range (25 to 29.9) and above the “healthy weight” BMI range (18.5 to 24.9). Also, many older adults whom the study found to be at highest mortality risk — those with BMIs under 22 — would be classified as having “healthy weight” by the WHO.

The study’s conclusion: “The WHO healthy weight range may not be suitable for older adults.” Instead, being overweight may be beneficial for older adults, while being notably thin can be problematic, contributing to the potential for frailty.

Indeed, an optimal BMI for older adults may be in the range of 24 to 29, Carl Lavie, a well-known obesity researcher, suggested in a separate study reviewing the evidence surrounding obesity in older adults. Lavie is the medical director of cardiac rehabilitation and prevention at Ochsner Health, a large health care system based in New Orleans, and author of “The Obesity Paradox,” a book that explores weight issues in older adults.

Expert recommendations. Obesity physicians and researchers offered several important recommendations during our conversations:

• Maintaining fitness and muscle mass is more important than losing weight for overweight older adults (those with BMIs of 25 to 29.9). “Is losing a few extra pounds going to dramatically improve their health? I don’t think the evidence shows that,” Lavie said.
• Unintentional weight loss is associated with several serious illnesses and is a danger signal that should always be attended to. “See your doctor if you’re losing weight without trying to,” said Newman of the University of Pittsburgh. She’s the co-author of a new paper finding that “unanticipated weight loss even among adults with obesity is associated with increased mortality” risk.
• Ensuring diet quality is essential. “Older adults are at risk for vitamin deficiencies and other nutritional deficits, and if you’re not consuming enough protein, that’s a problem,” said Batsis of the University of North Carolina. “I tell all my older patients to take a multivitamin,” said Dinesh Edem, director of the Medical Weight Management program at the University of Arkansas for Medical Sciences.
• Losing weight is more important for older adults who have a lot of fat around their middle (an apple shape) than it is for people who are heavier lower down (a pear shape). “For patients with a high waist circumference, we’re more aggressive in reducing calories or increasing exercise,” said Dennis Kerrigan, director of weight management at Henry Ford Health in Michigan.
• Maintaining weight stability is a good goal for healthy older adults who are carrying extra weight but who don’t have moderate or severe obesity (BMIs of 35 or higher). By definition, “healthy” means people don’t have serious metabolic issues (overly high cholesterol, blood sugar, blood pressure, and triglycerides), obesity-related disabilities (problems with mobility are common), or serious obesity-related illnesses such as diabetes or heart disease. “No great gains and no great losses — that’s what I recommend,” said Katie Dodd, a geriatric dietitian who writes a blog about nutrition.

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By Judith Graham
Kaiser Health News is a nonprofit news service covering health issues. It is an editorially independent program of the Kaiser Family Foundation, which is not affiliated with Kaiser Permanente.