5 Reasons You’re Suddenly Gaining Weight
(...even though you swear you haven’t changed anything)
Have you thought to yourself this year - why am I gaining weight out of nowhere??
Maybe you caught your reflection in a window and had to do a double-take... you haven't done anything differently with your eating and workouts, but you didn't realize you looked like THAT...so what gives??
If the scale’s creeping up despite your usual routine, you’re not alone—especially if you’re in your late 30s or 40s. Here’s what’s really going on and the #1 way to turn it around.
1. You’re Losing Lean Muscle Mass—Fast
Starting in your 30s, your body naturally begins to lose muscle at a rate that can add up fast—3-8% of your muscle mass per decade. Maybe that doesn’t seem like a big deal, so think about it this way:
If you’re a 30-year-old, moderately active, 160-pound woman, you might start with around 60 pounds of muscle. By age 40, you could lose up to 5 pounds of that muscle if you keep doing what you’ve always done. That’s a daily calorie burn decrease of about 30 calories—adding up to 10,950 fewer calories burned over a year, or about 3 pounds of potential weight gain annually, even if you’re eating and working out the same all along.
By the time you’re 50, you could lose up to 10 pounds of muscle, lowering your daily calorie burn by 60 calories. That’s 21,900 fewer calories per year, or around 6 pounds of potential weight gain each year due to muscle loss alone.
The above scenarios sound kinda bleak…and that’s only if you keep doing the same things as usual. These don’t even account for other potential setbacks that could arise like injury, illness, stress, or anything else life might throw your way - you can see how things could spiral quickly. That’s why strength training is so essential—it’s the best way to preserve muscle, keep your metabolism strong, and burn calories consistently. Lifting weights now helps you stay ahead of life’s ‘what ifs’ later on.
2. Your Body is Burning Fewer Calories at Rest
As estrogen levels decline, so does your resting metabolic rate (RMR) — the number of calories your body uses each day to keep you alive when you’re not active (like breathing, circulation, digestion, etc). RMR is the biggest source of your body’s daily calorie burn - up to 60-75% of overall calories! So when it slows down, weight gain can creep in quickly, even if your diet and activity levels stay the same. The best way to counter this? Strength training. Lifting weights increases muscle, which in turn boosts your RMR, helping you burn more calories around the clock and keep energy levels steady.
3. Your Blood Sugar is Harder to Control
With lower estrogen levels, many women begin to develop insulin resistance, making it tougher to keep blood sugar levels stable. Higher blood sugar can lead to weight gain, since excess sugar that isn’t used by the body gets stored as fat. It can also lead to increased cravings. The fix? You guessed it…lift those weights! Think of muscle as a “sponge” for blood sugar—it soaks up glucose for energy, which keeps blood sugar levels steady and reduces fat storage.
4. Your Body Fat is Shifting to Your Belly
Feeling more ‘apple’ than ‘hourglass’ lately? For many women, hormonal changes lead to body fat moving from their hips and legs to their midsection (where it may appear more “obvious”), especially as they approach perimenopause and menopause. Keep this at bay with…yup...strength training, which can help support a leaner-looking, more balanced physique.
5. The Little Things Add Up
It’s not just hormones—you gotta keep track of the little stuff, too. This is where some of my tough love comes in. That weekly glass of wine is now a few nights a week, walks are getting skipped, and “just one more episode” is pushing bedtime later. If you’re on auto-pilot, you might not even notice all of this is happening, making weight gain feel ‘unexplainable’. Yes, small things do add up…but you can use this to your advantage! Swap a glass of wine for a flavored seltzer, listen to your favorite juicy podcast on your walk breaks, or unwind at night with a book instead of a Netflix sesh (studies show that going screen-free before bed = deeper, higher quality sleep).
The more you understand what’s happening in your body at this stage of life, the better you can work with it—not against it. Managing weight and feeling good does get trickier with age, but it’s far from impossible. With a few smart, strategic tweaks, you can feel strong, lean, and energized…because feeling blah isn’t just a ‘normal’ part of aging.
Imagine catching your reflection in the window again and doing a double take—this time, not because you’re frustrated, but because you’re proud of who’s looking back. Strength training can help you get there (whether you’re already feeling all these hormonal shifts, or just want to get ahead of it).
If you’re ready to add weights to your fitness routine, but don’t want yet another thing on your mental load, click HERE to book a connection call with me. We’ll design a strength plan that’s practical, efficient, and fits seamlessly into your life—no guesswork, no extra hassle.