Why “Eat More Carbs” Hits Differently After 45
I was recently talking with my 22 year old nephew about training and food. At one point, he asked a question that sounded simple enough:
“If I’m trying to build muscle, do I need carbs—and how much?”.
For him, the answer is fairly straightforward. For women in midife, it usually isn’t.
This gap – the one between who a lot of nutrition advice is built for and some of us trying to follow it – is where a lot of well-intentioned social media nutrition advice can fall apart.
The Young Male "Growth" Bias
At 22, my nephew’s body is biologically biased toward growth: High testosterone and strong insulin sensitivity, ample lean muscle mass. When he eats carbohydrates, they tend to go exactly where they are supposed to - his active muscle tissue. His muscles are active, hungry and very responsive. A bowl of cereal or piece of toast before or after training isn’t confusing information for his body – it’s useful fuel.
In his context, carbs are a performance tool that support training volume, help with recovery, and speed up recovery.
His body has a very clear answer to the question: what should I do with this energy?
The Midlife Shift
For many of us in perimenopause or post-menopause, that clarity fades. Not because anything is wrong, but because the metabolic context has shifted. As estrogen declines, the way we handle fuel shifts.
Insulin sensitivity often drops, making muscle cells less responsive to glucose knocking at the door.
Glucose stays in circulation longer, rather than being whisked away into cells
Central fat storage increases, as excess energy is more easily diverted to the midsection
Stress plays a role here too. Cortisol can further complicate blood-sugar control, which is why energy highs and lows often feel sharper than they used to.
This isn't a "metabolic failure"—it is normal female physiology for this stage of life.
It does mean the same advice we may have followed before can land very differently now.
In an earlier post, I talked about the protein threshold and why hitting it matters more in midlife than it once did. Protein gives the body the raw materials it needs to protect muscle in the face of age-related resistance.
Once those building blocks are in place, the next question tends to come up naturally:
How do we fuel the engine without causing energy crashes or unwanted storage? What about carbs?
What carbs do differently after menopause
A key nutrition goal in midlife is muscle preservation. Here, carbs are not the driver - protein intake and resistance training matter far more.
Without sufficient stimulus, muscle loss accelerates with age – even in active women.
When the goal is preservation:
Carbohydrates are not required to drive muscle maintenance
Protein intake and resistance training matter far more
Excess carbohydrates without muscle activation are more likely to be stored
Stable blood sugar often matters more than training fuel
In this context, carbs work best when:
paired with sufficient protein
eaten in moderate amounts
included in meals rather than as a stand-along fuel
Here, carbohydrates are supportive, not central.
That’s where the 'Order of Operations' for carbohydrates comes in.
Changing the "Order of Operations"
In a younger body, carbohydrates can help build muscle. In a midlife body, we have to flip that - we use muscle to guide what happens to carbohydrates.
One of the important things to note – and one that often gets missed online – is that muscle contraction itself increases glucose uptake. You don’t need insulin to do all the work. Active muscle creates its own demand.
When muscle is regularly challenged – such as through resistance training - the door to your muscles cells unlocks and you create a metabolically active “sink”.
In simple terms, training creates somewhere useful for fuel to go. Without that signal, carbohydrates become “unemployed” — and without a job to do, are much more likely to be stored as fat.
Movement in midlife isn’t just about calories or steps. It’s about keeping the machinery online.
Strategic Fueling: A Practical Approach
This isn't about restriction; it’s about fuel direction. To make carbohydrates work for you rather than against you, try these three adjustments:
Prioritize the Signal: Focus on 2 to 3 resistance sessions a week. Short and focused is enough to tell your body to prioritize muscle repair over fat storage.
Use the "Fiber Buffer": It’s not just about where carbohydrates go – it’s about how quickly they arrive. An "unbuffered" carb—like white bread or a sugary snack on its own—can hit a midlife bloodstream like a tidal wave. For a midlife body, that can demand an insulin response that’s harder to manage smoothly. By pairing carbs with, or choosing carbs that are, high-fiber vegetables, you slow that entry and protect your energy from the "spike and crash" cycle. Insulin can do its job quietly, without becoming a signal for storage.
Context Matters: Carbs work best when they are paired with that 35–40g protein threshold we discussed in an earlier post. Instead of stand-alone fuel, treat them as a supportive partner to your protein intake.
The Key Takeaway
Same macronutrient. Different life stage. Different rules.
The question isn’t “Do I need carbs?”. It’s “What is my body trying to do with them right now?”
For young adults building muscle, carbohydrates can support training volume and recovery
For midlife women preserving muscle, carbohydrates play a smaller, supporting role.
For midlife women building muscle, carbohydrates work best after muscle has been consistently activated through resistance training.
When nutrition matches physiology, things calm down. You stop fighting your body and give it the right fuel for the right job.
References
1. Dionne, I. J., et al. (2003) Effect of menopause on insulin sensitivity and glucose metabolism. Diabetes Care, 26(10), 2879–2885
2. Rettberg, J. R., et al. (2014) Estrogen, insulin signaling, and glucose metabolism in aging females, Frontiers in Neuroendocrinology, 35(4), 515–528
3. Holloszy, J. O. (2005). Exercise-induced increase in muscle insulin sensitivity. Journal of Applied Physiology, 99(1), 338–343
4. Morton, R. W., et al. (2018). Protein intake to maximize resistance-training adaptations. British Journal of Sports Medicine, 52(6), 376–384
5. Vargas-Molina, S., et al. (2022), Carbohydrate intake and resistance training performance: a systematic review, Nutrients, 14(4), 856.
6. Phillips, S. M., & Winett, R. A. (2010), Resistance training and health-related outcomes across the lifespan. Sports Medicine, 40(1), 1–24.
This article is for educational purposes only and does not constitute medical advice. Individual needs vary. Please consult a qualified health professional for personalised guidance.
