Many women notice that weight maintenance gets harder in their 30s, and harder still in their 40s. It just takes more effort to move the needle in the right direction with every passing decade. We often blame hormonal changes as the culprit. In reality, while hormones do complicate things, they’re usually not the whole story. There’s a sneaky and invisible process that begins in your 40’s (maybe even earlier) which shifts your body composition and messes with your metabolism, and no one is immune. But the good news is that you can fight it.
Known as sarcopenia (1), age-related muscle loss is an insidious driver of metabolic dysfunction and fat gain. Underlying causes include mitochondrial dysfunction, inflammation, and decreased physical activity. This last one, your activity level and activity type, is the most important to pay attention to, because it’s the lever you can pull most readily to address the other causes, including those hormones we’re sure are the problem.
Sarcopenia can deplete muscle mass by 3% to 5% per decade. It’s usually not noticed because it happens so slowly. Your body replaces the lost muscle with fat, so you don’t appear to lose body mass or change size much, although you might be a little lighter (because fat is not as heavy as muscle). But you do lose lean muscle tissue which is your main engine for glucose disposal and calorie burning! Even at rest, your muscle cells use 3x more calories than your fat cells (6 calories vs. 2, according to Claude Bouchard (2), a researcher at Pennington Biomedical). Compared to fat, muscle is practically a calorie-burning powerhouse, and preserving it is crucial for weight maintenance, to say nothing of bone health, brain health, functional strength, and overall longevity. (3)
Regular resistance training is the key to reversing sarcopenia. Increasing your muscle mass and activity level will positively influence your hormones and mitochondrial function while eliciting changes that reduce inflammation and body fat deposition (4). The more muscle you retain (or rebuild), the higher your metabolism will ultimately be. As long as you continue challenging yourself, the effects of weight training won’t diminish: you’ll continue adding lean mass over time. If you do this while maintaining your weight, you’ll notice your body getting leaner, not bigger.
Now, even when we exercise regularly, if we aren’t challenging our muscles, sarcopenia will sneak up on us. How do I know this? It happened to me! I was 45. I was an avid exerciser (mainly cardio and calisthenics with some light weightlifting). But one summer, I could suddenly see cellulite on the front of my thighs. My weight and size were unchanged. But my body composition had shifted: I was fatter at the same weight, and my skin could no longer lay smooth over the fat.
I blamed this on collagen loss associated with aging and reduced estrogen, even though I wasn’t yet in menopause. I unhappily put the mini dresses at the back of the closet. And then I did what I always do: I got to work looking for a solution.
For me, it was the side lunge. With 15# dumbbells. Late one night I watched a YouTube video of a men’s fitness instructor doing a crazy leg workout, and I decided to try it myself. Now, it was not an overnight success in terms of fixing cellulite, but the difference in my strength and agility impressed me so much that I kept at it. And I kept moving heavier weights and doing other more challenging leg moves that were fun. A year later I looked down and realized that the cellulite was gone. Fourteen years later, it’s still gone, and my legs are even leaner and smaller…they’re actually cut! So, break out the weights and train hard….keep pushing. I’m living proof that you can definitely reverse sarcopenia and burn fat, no matter your age. And the sooner you start, the better.
The second key to avoiding weight gain in your forties is your diet. Most importantly, choose a diet you can live with, one you’ll sustain. Stick to it every day. Once you find what works for you and doesn’t make you feel deprived, that’s a great place to be.
You should keep track of your caloric intake even if you aren’t trying to lose weight, as it’s incredibly helpful to quantify how much you can eat without gaining weight. If you prefer to count carbohydrates or fat grams, that can work, too, depending on the diet framework you choose. Just track a metric that makes the most sense for you and feels easy to keep doing.
One macronutrient to optimise is protein. Don’t skimp on it. You can’t build lean muscle without it. Adequate protein is critical for maintaining both muscle and bone mass (but getting much more than you need does not help). Protein also has the benefit of being very satiating, and it creates a higher thermic effect of food (a slightly increased metabolism as the body processes food to release energy). (6) While this doesn’t translate into a big boost, every little bit helps.
My number one recommendation in terms of diet, however, can be applied no matter what diet framework you choose: cut out the empty calories. It becomes pretty hard to get away with consuming empty calories of any kind once we’re in our forties. Start to critically evaluate how much nutrition you’re getting for the calories in any given food. Few of us can afford empty calories as we get older, and they have a way of creeping into even the most well-intentioned seemingly virtuous diets. Vegan cream cheese and all-fruit jam on gluten-free toast, anyone? Butter coffee? There are many empty calorie traps out there, no matter what they’re called or who’s recommending them.
Maintaining your weight as you age requires vigilance. But, speaking from experience, it’s absolutely worth it, and it only gets easier over time! Now, let’s head to the gym!!
