Do you find it easier to gain weight as you get older, even if you eat the same?
Your metabolism may be part of the picture—but it's not the whole story.
While many people assume metabolism steadily slows throughout adulthood, recent research suggests resting metabolism remains relatively stable from around ages 20 to 60 before gradually declining later in life.1 However, age-related changes in muscle mass, physical activity and body composition can make weight management more challenging.23
Fortunately, there are several evidence-based ways to support a healthy metabolism as you age.
Here's what the research says.
Does your metabolism slow down?
Metabolism refers to all the chemical reactions your body uses to convert food into energy needed for everyday functions.
Your metabolic rate influences how many calories your body uses each day. Factors including age, body size, muscle mass, genetics and physical activity all contribute to metabolic rate.4
Although resting metabolism changes very little throughout most of adulthood, muscle mass naturally declines with age, while physical activity often decreases. Together, these changes can reduce the number of calories you burn each day.56
Summary
Healthy ageing is often accompanied by changes in muscle mass and activity levels that can reduce daily energy expenditure, even though resting metabolism remains relatively stable until later adulthood.
What can you do about it?
Although ageing is inevitable, there are several evidence-based strategies that can help support a healthy metabolism.
Resistance training is one of the most effective approaches. Studies show that regular strength training helps preserve or increase muscle mass and can increase resting metabolic rate in older adults.78
If traditional weight training isn't for you, high-intensity interval training (HIIT) is another effective option. HIIT can improve fitness, help preserve lean muscle and increase post-exercise energy expenditure, meaning your body continues burning additional calories for several hours after exercise.910
Getting enough quality sleep is also important. Chronic sleep restriction has been associated with poorer metabolic health, increased appetite and reduced muscle protein synthesis.11
From a nutrition perspective, eating enough food to meet your body's needs is essential. Prolonged, severe calorie restriction can reduce energy expenditure as the body adapts to conserve energy.12
Finally, prioritising protein-rich foods can help preserve muscle mass and slightly increase calorie burning because protein has a higher thermic effect than carbohydrates or fat.13
Summary
Resistance training, HIIT, adequate sleep, sufficient energy intake and consuming enough protein can all help support healthy metabolism and maintain muscle mass as you age.
