As we grow older, our metabolisms slow down, partly due to less physical activity, loss of muscle mass and overall effects of aging, explains Kathryn Reilly M.D., M.P.H., a professor of family medicine at the University of Oklahoma Health Sciences Center in Oklahoma City.
But weight gain doesn’t have to be inevitable with age. Reilly says older adults can increase their exercise and muscle mass to not only lose weight but maintain their current weight.
She says the main reason for weight gain over the years is that people decrease – or completely stop – exercising.
“According to research, at least a quarter of people aged 50 to 65 don’t do any exercise outside of work, and as people age, this figure increases to at least a third,” says Reilly. In addition, people can lose up to 8% of muscle mass per decade after the age of 30.
“Cumulatively, this can lead to a 30% loss of total muscle mass by the age of 80,” she says. “Less muscle mass slows down metabolism, because muscle uses more energy than fat tissue in the body. Muscle mass also declines because of hormone levels decreasing, but this can be counteracted by exercise.”
Reilly highlights a study comparing the resting metabolic rate in three groups of adults: 20- to 34-year-olds, 60- to 74-year-olds, and over 90-year-olds.
“They found that the 60- to 74-year-old adults burned 122 fewer calories than the younger group, and people over 90 burned 422 fewer calories. However, when they considered differences in gender, muscle and fat, the 60- to 74-year-olds only burned 24 fewer calories, and those over 90 burned 53 fewer calories than the younger group,” she says.
This research, along with many other studies, supports the knowledge that regular exercise – including both aerobic exercise and resistance training – is beneficial to every adult at any age. Exercises that improve balance are also important as they can help to prevent falls.
“The recommended minimum amount of exercise for all adults is 150 minutes per week – an average of 30 minutes, five days per week,” says Reilly. “More is better, although there is no apparent benefit to getting more than 300 minutes per week.”
She recommends that anyone who has not been regularly active should visit with their physician and/or personal trainer before beginning a new exercise routine.
Along with physical activity, a healthy diet is essential. Reilly says a serving of protein three times a day can be helpful, as the daily recommended amount for adults is typically 60 to 80 grams – with cheese and nuts being a good source of protein and more beneficial than crackers or chips.
“Not eating enough good calories can also lead to slower metabolism,” she says. “A diet high in relatively unprocessed foods is much more likely to enhance a healthy body.”
While weight gain with aging may be common, some people find themselves losing weight.
“Weight loss in older adults can occur in those with chronic illnesses, poor dentition, or loss of sense of taste,” says Reilly, adding that individuals who experience weight loss should consult their doctor and/or dentist to find the cause.
