Carbs, Protein, Fat: Why the Balance Shifts in Your 40s
I grew up in a house where breakfast was cereal or oatmeal, lunch was a sandwich and a piece of fruit, snacks were granola bars and bananas, and dinner was always homemade every single night. My mom cooked; I was spoiled in the best way.
But once I entered the working world of fitness, those meals flew out the window. My schedule (clients, early mornings, late nights) meant many days I grabbed a caffeinated protein drink and a banana and hoped it’d hold me through 4–6 hours of back-to-back sessions. Spoiler: it didn’t.
By my early 30s I realized I’d gained around 25 pounds since college, even though I wasn’t doing anything dramatically different—or so I thought. I had no consistent eating plan. So I went back to the drawing board with what I now call boring meals: simple, frequent, balanced. And I always felt better.
That’s when I started noticing what I teach my clients regularly: what used to work doesn’t always anymore. The macro ratios, the energy levels, the recovery time—all of it starts shifting. It’s not you. It’s biology. And your macro balance needs to shift too.
What Happens in Your Body in Your 40s / Perimenopause
Here’s what changes under the hood:
• Hormonal shifts: Estrogen and progesterone decline during perimenopause. Lower estrogen is linked to reduced insulin sensitivity, meaning carbs that used to be no problem can now cause bigger blood sugar swings.
• Metabolic slowdown and muscle loss: After 30, we naturally lose muscle mass (unless we train smart). Muscle is metabolically active, so less of it means a lower metabolic cushion and slower calorie burn.
• Appetite signals shift: Hormones like leptin and ghrelin (which regulate fullness and hunger) become less predictable, making it easier to over- or under-eat.
• Inflammation and slower recovery: Midlife brings higher baseline inflammation, which means what you eat has a bigger effect on joints, energy, and even mood.
Macronutrient Deep Dives
A. Carbohydrates
• What used to work: Fueling heavily with carbs gave quick energy and faster recovery, especially if you were more endurance-based.
• What shifts: Reduced insulin sensitivity in your 40s means carbs may hit harder, leading to spikes, crashes, or cravings. High-sugar carbs may also trigger more inflammation or GI distress.
• How to shift:
– Prioritize complex carbs (veggies, legumes, whole grains)
– Time carbs around workouts or earlier in the day
– Dial back processed and sugary carbs to reduce energy swings
• In practice: Overnight oats with berries, beans on your salad, roasted veggies with dinner, swapping crackers for hummus and raw veggies
Note: as a rule or thumb women need 25 g of fiber each day; 30 g once you turn 40. Men need 30 g, and 40 and over need 35 g.
B. Protein
• What used to work: Moderate protein felt fine when recovery was faster and muscle maintenance wasn’t top of mind.
• What shifts: Protein becomes essential to offset muscle loss, aid recovery, and support bone health. Research suggests women in perimenopause benefit from .8–1.0 g of protein per pound of bodyweight daily for muscle maintenance.
• How to shift:
– Aim for 25–35 g protein at every meal
– Spread intake across the day, rather than loading at dinner
– Use high-quality sources like lean meats, eggs, fish, dairy, beans, or powders if needed
• In practice: Collagen and protein milk in coffee, protein powder in smoothies, tuna packets with whole-grain crackers, 6 oz chicken or pork at dinner
C. Fat
• What used to work: Low-fat everything. Fat makes you fat was the old diet dogma.
• What shifts: Healthy fats are critical for hormone production, brain health, satiety, and absorbing fat-soluble vitamins. Omega-3s, in particular, may reduce inflammation and support heart and joint health.
• How to shift:
– Add omega-3s from salmon, sardines, flaxseed
– Use olive or avocado oil for cooking
– Balance saturated fats instead of eliminating them
• In practice: Avocado in a shake, raw nuts as snacks, coconut milk in oats, salmon or sardines for dinner
Putting It Into Practice
Your macro balance in your 40s doesn’t need to be perfect. It just needs to shift. Here’s what that looks like in action:
• Classic balance: Protein at each meal, carbs earlier in the day or around workouts, healthy fats sprinkled throughout
• Strength day: Higher protein, moderate carbs, moderate fat
• Rest or recovery day: Moderate protein, lower carbs, a little more fat for satiety
Tip: track your meals for a week and notice your energy, mood, and recovery. Adjust from there.
What I Do Daily
Our dinner the other night; pan seared pork chop in olive oil, parboiled rice and steamed fresh corn off the cob
Here’s a snapshot of how I put this into practice right now:
• Early morning: Shake with collagen, vegan protein, Fairlife milk, berries, egg whites (about 70 g protein + fiber)
• Breakfast: Overnight oats with coconut milk, seeds, homemade muesli, raisins (about 15 g protein + fiber)
• Lunch: Babybel cheese, tuna packet, grapes, crackers (about 25 g protein + fiber)
• Dinner: Chicken or pork with baked veggies and rice or sweet potato. Often soup with beans and fresh protein for variety — I use my Soup Blueprint to mix and match veggies, proteins, and flavors.
For me, it works best to load protein earlier in the day: about 85 g by breakfast, 25 g at lunch, and 25–40 g at dinner. I follow the 80/20 rule: hit your numbers most of the time, not perfectly every day.
Conclusion + CTA
Your body isn’t broken. It’s just changing. And your nutrition can change with it. Carbs, protein, and fat all still matter. You just need to redefine the balance.
👉 Want to go deeper into how to train, fuel, and recover smarter in your 40s? Watch my free masterclass: The Fitness Rules You’ve Been Sold Are Wrong.
References
https://www.health.harvard.edu/womens-health/why-women-gain-weight-in-midlife
https://www.nia.nih.gov/health/aging-changes-body-shape-and-metabolism
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4255578/
https://jissn.biomedcentral.com/articles/10.1186/s12970-017-0187-9