Muscle Plays a Role in Weight Loss—But Not How You Think

Reported by Women's Health Magazine.

The fitness internet loves a clean narrative, and few have been more durable than this one: build muscle, torch calories, watch fat disappear. It's tidy. It's motivating. It's also, according to Women's Health Magazine, significantly overstated.

Yes, muscle tissue is more metabolically active than fat — but the real-world math is humbling. Stuart Phillips, PhD, a kinesiology professor at McMaster University and muscle researcher, puts it plainly: one pound of muscle burns roughly five to seven calories per day at rest versus about two for fat. Add five pounds of muscle and you're looking at an extra 20 to 30 calories burned daily — meaningful over time, but nowhere near the metabolic revolution the fitness industry implies. "Gaining five pounds of muscle isn't going to add hundreds of calories to your resting metabolism," Phillips says. Fat loss still requires an energy deficit. No amount of muscle changes that fundamental equation.

What Muscle Actually Does for Your Body

The stronger case for building muscle isn't passive calorie burn — it's everything else. Rachelle Reed, PhD, ACSM-EP, exercise physiologist and Head of Scientific Research at Therabody, points to improved insulin sensitivity and better long-term body composition as the real payoffs. Muscle is a primary storage site for glucose, meaning more of it translates to better blood sugar regulation and a lower risk of insulin resistance — a condition that Aja Campbell, CSCS, founder of ATTAGIRL and sports medicine lead at The Mary Louis Academy, links directly to both type 2 diabetes risk and weight gain. Then there's NEAT — non-exercise activity thermogenesis, the calories burned through ordinary daily movement. More functional strength means everyday tasks feel easier, you move more without thinking about it, and those accumulated calories add up. It's a compounding effect that no supplement can replicate.

Phillips also makes the case that the behavioral habits surrounding muscle-building may matter as much as the muscle itself. People who strength train consistently tend to eat more protein, sleep with more intention, and pay closer attention to recovery — all of which independently support fat loss. The muscle isn't the magic. The lifestyle architecture around building it is. If fat loss is the goal, Phillips recommends training at least two to three days per week with compound movements — squats, deadlifts, bench press, pull-ups — pushing close to failure and applying progressive overload over time. Campbell adds that hitting around 12 or more sets per muscle group weekly, in a simple full-body structure, is where results actually come from. On the nutrition side, a moderate calorie deficit paired with adequate protein preserves lean mass while shedding fat — aggressive restriction, by contrast, undermines the muscle you're working to build. Reed rounds it out with a recovery mandate: seven to nine hours of sleep, plus consistent mobility work, because disrupted sleep throws hunger hormones leptin and ghrelin out of balance and quietly derails everything else.

The bottom line: muscle won't rewrite your metabolism overnight, but the disciplined, consistent work of building it will — and that's a more honest reason to start lifting than anyone's been giving you.

Read the original at Women's Health Magazine.