Simply cut off the soda supply and your average guy will seem to drop five pounds overnight. Meanwhile, many women overhaul their diets and work out five times a week, and still struggle to lose one measly pound.
It’s infuriating—at least for women. But what’s behind this weight-loss inequality?
Much of the difference between how men and women lose weight comes down to their levels of fat-free mass, explains board-certified family and bariatric physician Spencer Nadolsky, D.O., a diplomat of the American Board of Obesity Medicine. Fat-free mass includes every bit of your body that isn’t fat—like organs, bones, connective tissues, and muscle.
Guys tend to have way more mass, including fat-free mass, than women. (After all, the average guy in the U.S. is five-foot-nine, while the average gal is five-foot-four, according to the CDC.) According to PLOS ONE research, the size of a person’s kidneys, brain, and liver greatly contribute to their resting energy expenditure (the number of calories burned doing nothing). Plus, research published in the British Journal of Nutrition confirms that after accounting for lean body mass levels there’s little to no difference between the resting metabolisms of men and women. So it makes sense that larger guys (and their larger organs) burn more calories than smaller women.
Related: 5 Myths About Your Metabolism—Busted
“Calories are fuel. And the bigger your body’s engine, the more fuel you are going to need and burn every day,” Nadolsky explains. “It’s also easier for you to cut calories from your daily intake without feeling like you’re starving.”
Think of it this way: If you’re a guy who burns 2,500 calories per day just binge-watching Netflix, you can cut 500 calories to lose weight and still be eating 2,000 calories a day. But if you’re a girl with a resting metabolic rate of 1,500 calories, you can only safely cut 300 calories—most experts recommend a minimum of 1,200 calories a day—a deficit that won’t move the scale’s needle all that quickly. The same thinking applies to workouts. A big guy is going to burn far more calories running a mile than will a petite woman.
Still, size doesn’t explain everything. For instance, according to research from the National Institutes of Heath, women’s daily energy expenditure varies by about 100 calories or so throughout their menstrual cycle. (It’s highest during the luteal phase.)
Yep, this is where hormones come into play. After all, the luteal phase (which begins after ovulation) involves a delicate interplay of hormones, including estrogen, which peaks at menstruation and then tapers off, and progesterone, which increases throughout the luteal phase and then nosedives to help trigger menstruation.
Animal research published in Endocrinology and Metabolism suggests that a woman’s natural estrogen (called estradiol) and progesterone may promote fat retention and discourage lean muscle formation. But meanwhile, research published in Diabetes links declining levels of estrogen and progesterone during menopause with the body’s cells becoming more likely to store fat. So women’s hormonal fluctuations—and their impact on weight—are definitely a bit more complicated than men’s.
And then there’s the hormone of note for guys: testosterone. An anabolic hormone (meaning it helps build tissues in the body) testosterone contributes to muscle formation. Men have 15 times as much testosterone as women, largely explaining why men have a greater propensity for putting on lean, metabolism-boosting muscle, says Neerav Padliya, Ph.D., vice president of Research Alliances at MYOS RENS bionutrition and biotherapeutics company. Having all that extra muscle no doubt contributes to men’s faster metabolisms.
In the end, these hormonal differences do influence weight-loss efforts, but women can hack guy-style weight loss with the right strategy.
Muscle Up: How to Lose Weight Like a Guy
It all comes down to muscle. “Lean mass is the largest source of energy expenditure in the body, and the only one which is variable,” Padliya says. So by increasing how much muscle you have (a major part of that being lean mass), you can pump up your calorie-burning potential.
So, to boost your muscle mass, metabolism, and weight-loss results, your first step is to perform more strength training, ideally with heavy loads (sets of six to 12 reps) and shorter recovery times (30 to 60 seconds between sets). This sort of protocol is optimal for muscle-building, partly because it triggers a short-term spike in T levels, Nadolsky says.
From there, make sure to complement your muscle-building workouts with muscle-friendly nutrition. According to a 2015 review published in Applied Physiology, Nutrition, and Metabolism, people need to get about 25 percent of their daily calories from protein in order to increase muscle mass lose weight (in combination with strength training).
Ideally, each meal and snack should contain somewhere around 25 to 35 grams of protein to stimulate maximum muscle growth. That’s roughly the equivalent of a cup of Greek yogurt with a sprinkle of nuts, one half-cup of chopped chicken breast, or a two-egg omelet with veggies, milk, and cheese mixed in.
Sure, should guys follow these tips, they’re likely going to put on more muscle than women. But any muscle women can build puts them a step closer to easier weight loss.