The protein figure you were given is a minimum designed to stop deficiency, not an amount that preserves muscle in your forties. That gap is the single most useful thing to understand about midlife nutrition, and it explains why so many women eating what they think is a sensible diet are losing lean mass anyway.
Two different numbers
The reference intake most people have heard — around 0.8 g of protein per kilogram of body weight — is a floor. It was established to prevent deficiency in the general population, and it does that job.
The amount associated with maintaining muscle in older adults is higher: research in this area generally points to somewhere around 1.2 to 1.6 g per kilogram a day, and toward the upper end if you are training or in a calorie deficit. For a woman of 70 kg that is roughly 85 to 110 g a day, against a floor of 56.
Most women in perimenopause are eating closer to the floor. Not because of carelessness — because that is what the guidance said.
Why it rises with age
Older muscle is less responsive to protein. The same 15 g that triggered muscle protein synthesis at 25 may not clear the threshold at 50 — a phenomenon usually called anabolic resistance. The practical consequence is not just "eat more protein" but eat more per sitting.
Which is why the distribution matters as much as the total.
The breakfast problem
Most people eat a small amount of protein at breakfast, a moderate amount at lunch, and most of the day's total at dinner. That shape wastes it. One large evening dose does not compensate for two meals that fell below the threshold, because the response is per-meal rather than cumulative.
Aim for 25 to 40 g at each main meal. In practice the fix is almost always breakfast, and it is the highest-return change in this article:
- Toast and jam: around 5 g. Below the threshold.
- Cereal with milk: around 10 g. Below the threshold.
- Three eggs: around 19 g. Close.
- Greek yogurt with a scoop of whey and seeds: 35 g plus. There.
This is the specific reason protein powder exists as a category — not as a weight-loss product, but as a way of hitting a breakfast number that is otherwise difficult without cooking.
Whey, plant, or food
- Food first, genuinely. Eggs, dairy, fish, meat, legumes, tofu. Whole foods bring the rest of the nutrition with them.
- Whey is high in leucine, the amino acid that does most of the signaling, and it is the most studied. Whey isolate is lower in lactose if that is an issue.
- Plant proteins work, and generally need slightly more per serving to match the leucine content. Blends — pea with rice, for instance — are better than single sources.
- Collagen is not a substitute. It is incomplete and low in leucine. It has its own uses; hitting a protein target is not one of them.
The kidney question
Higher protein intake does not damage kidney function in people with healthy kidneys. That concern comes from advice given to people who already have kidney disease, where it is appropriate, and has been generalized to everyone else, where it is not. If you have reduced kidney function, this is a conversation with your clinician.
Protein alone does less than you would hope
This is the part the supplement industry leaves out. Protein is the raw material; resistance training is the signal that tells your body to use it for muscle. Eating 110 g a day without lifting does far less than eating it while lifting twice a week.
The pair is the intervention. Neither half works well alone, and if you can only do one, the training is the one that changes more.
Two situations where it matters more
- In a calorie deficit. Losing weight means losing some lean mass unless protein and training are protecting it. Aim high in the range, not low.
- On GLP-1 medication. Appetite drops sharply, which makes hitting a protein target harder exactly when muscle preservation matters most. If you are on one, protein and resistance training become more important, not less. That is a conversation worth having with your prescriber.
How to actually do it
- Work out your target once. Body weight in kg times 1.2 to 1.6.
- Count one ordinary day honestly. Most people are 30 to 40 g short and surprised by it.
- Fix breakfast first. Bigger return than anything else you will change.
- Put a real portion at each meal rather than backloading to dinner.
- Add resistance training twice a week, or the protein is raw material with no instruction.
The short version
- 0.8 g/kg is a deficiency floor. Muscle maintenance in midlife is more like 1.2 to 1.6 g/kg.
- Older muscle needs more protein per meal to respond, so distribution matters as much as the total.
- Target 25 to 40 g per main meal. Breakfast is almost always the gap.
- Whey is the most studied; plant blends work with slightly more; collagen does not count.
- High protein does not harm healthy kidneys.
- Without resistance training, protein does much less. The pair is the intervention.
- In a deficit or on a GLP-1, protein matters more, not less.
This article is general information, not medical advice. Talk to a clinician about your own needs, particularly if you have reduced kidney function or take weight-loss medication. These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure or prevent any disease.
