Why Metabolism Slows With Age

"My metabolism isn't what it used to be" is a common complaint, and research on aging and metabolic rate suggests there's real physiological truth behind it, alongside some nuance worth understanding.

What Research Actually Shows About Age and Metabolic Rate

Longer-term research on metabolic rate across the lifespan has found that resting metabolic rate does decline somewhat with age, though the timing and magnitude are more gradual and nuanced than the common "metabolism crashes at 40" narrative suggests.

Muscle Mass: A Major Contributing Factor

Muscle tissue is more metabolically active than fat tissue, and age-related muscle loss (sarcopenia), which can begin accelerating without deliberate resistance training, is one of the more concrete, addressable contributors to declining metabolic rate over time.

Hormonal Changes Also Play a Role

For women specifically, the hormonal changes associated with perimenopause and menopause are separately linked to shifts in body composition and fat distribution, a topic covered in more depth in our dedicated menopause piece.

What Can Be Actively Addressed

Unlike some aspects of aging, muscle mass responds directly to resistance training at any age — research consistently finds that strength training helps preserve or even rebuild metabolically active muscle tissue, partially offsetting age-related metabolic decline.

A Realistic, Encouraging Takeaway

While some metabolic slowing with age is real, it's not an unstoppable, purely passive process — muscle-preserving activity and consistent nutritional support, including the metabolic focus behind formulas like MomBurn, are both actionable levers.

Age-related metabolic slowing is real but partial, and muscle-preserving activity remains one of the most genuinely actionable levers available at any age.