# Protein After 40 for Women: Grams per Kilo, per Meal, and Plant Foods That Get There

How much protein a woman over forty needs to keep and build muscle: 1.2 to 1.6 g per kilo, 25 to 30 g per meal, why timing matters, leucine, and the plant foods with grams per portion.

By Barbara · 2026-10-23 · https://strongatforty.com/protein/protein-after-40-women

After forty, muscle answers protein less eagerly than it did at twenty-five. Researchers call it anabolic resistance: the same 15 g of protein that switched on muscle building in a younger body no longer clears the threshold. The answer is not a powder-fuelled diet; it is a higher floor per meal and a higher total per day, spread evenly, on foods you already eat. On a plant-based plate that takes a little planning and no compromise: when protein is matched gram for gram, plant and animal diets built the same muscle in the trials that bothered to match them.

## The numbers

| Reference | Amount | For a 65 kg woman |
|---|---|---|
| EFSA population reference intake, all adults | 0.83 g per kg a day | 54 g |
| PROT-AGE position, older adults, to keep muscle | 1.0 to 1.2 g per kg a day | 65 to 78 g |
| The training plateau, Morton meta-analysis | about 1.6 g per kg a day | 104 g |
| Per meal, to switch muscle building on | 25 to 30 g, with 2.5 to 3 g leucine | three meals |
| Distribution | even across three meals | about 25 percent more muscle built over a day than the same protein skewed to dinner |

The practical target for a woman over forty who lifts: 1.2 to 1.6 g per kg, in three meals of 25 to 35 g. For most women that is 80 to 100 g a day, and the shortfall, when the log is counted, is nearly always at breakfast and lunch.

## Leucine, the switch

Muscle protein synthesis is triggered mostly by one amino acid, leucine, and a meal needs about 2.5 to 3 g of it to clear the threshold after forty. Soy, pea, lentils and seitan carry enough per 25 to 30 g serving of protein; grains and vegetables do not, which is why a bowl of quinoa and broccoli, however large, does not count as a protein meal. Anchor every meal on a legume, a soy food or seitan, and the leucine takes care of itself.

## Plant proteins, per portion

| Food | Portion | Protein | Leucine |
|---|---|---|---|
| Seitan | 100 g | 25 g | 1.8 g |
| Soy protein powder | 30 g scoop | 25 g | 2.1 g |
| Pea protein powder | 30 g scoop | 22 to 25 g | 2.0 g |
| Tempeh | 100 g | 19 g | 1.5 g |
| Lentils, cooked | 200 g | 18 g | 1.3 g |
| Black beans, cooked | 200 g | 17 g | 1.4 g |
| Firm tofu | 150 g | 17 g | 1.4 g |
| Edamame, shelled | 1 cup (155 g) | 17 g | 1.4 g |
| Chickpeas, cooked | 200 g | 15 g | 1.1 g |
| Hemp seeds | 30 g | 9 g | 0.6 g |
| Pumpkin seeds | 30 g | 9 g | 0.7 g |
| Oats, dry | 60 g | 8 g | 0.6 g |
| Soy milk | 250 ml | 7 to 8 g | 0.6 g |
| Peanut butter | 30 g | 8 g | 0.6 g |

## Three meals that each reach thirty grams

**Breakfast, 31 g.** Porridge from 60 g of oats on 300 ml of soy milk, 20 g of hemp seeds, a spoon of peanut butter, berries. Five minutes; the oats do the rest.

**Lunch, 33 g.** A bowl of 200 g lentils with tomatoes and a squeeze of lemon, 100 g of firm tofu seared in the same pan, pea shoots on top. Cook the lentils on Sunday.

**Dinner, 34 g.** 100 g of tempeh with 150 g of black beans, roasted roots, tahini, a handful of pumpkin seeds. The leftovers are tomorrow's lunch.

The post-workout version: a shake of 30 g pea protein in soy milk with a banana, 35 g, in the hour after training when the kitchen is not an option.

## The rules after forty

**Breakfast is the meal to fix first.** Most women eat 8 g at breakfast and 50 g at dinner. Moving protein to the morning does more for muscle than adding it at night.

**Thirty grams, three times, beats ninety once.** The Mamerow crossover trial found about 25 percent more muscle protein synthesis over a day from an even spread than from the same total skewed to dinner.

**Lift, or the protein has nowhere to go.** Two or three strength sessions a week are the reason the body keeps what it eats.

**Powder is a tool, not a confession.** A scoop in the oats is the fastest 20 g on a difficult morning.

**Count it for three days.** A kitchen scale and a free app. The number is almost always 20 to 40 g lower than you think, and the shortfall is in the first half of the day.

## What the research says

- Bauer and colleagues, Journal of the American Medical Directors Association, 2013, PROT-AGE expert position paper: older adults need more than the 0.8 g per kg RDA to maintain muscle, with 1.0 to 1.2 g per kg a day and 25 to 30 g per meal suggested to trigger muscle protein synthesis. The contrary finding: an expert consensus rather than a trial, written about people over 65. [doi.org/10.1016/j.jamda.2013.05.021](https://doi.org/10.1016/j.jamda.2013.05.021)
- Morton and colleagues, British Journal of Sports Medicine, 2018, meta-analysis of 49 randomised trials with 1,863 participants: adding protein to resistance training increased one-repetition-maximum strength by 2.49 kg and fat-free mass by 0.30 kg beyond training alone, plateauing beyond about 1.6 g per kg a day. The contrary finding: the effect shrank with age. [doi.org/10.1136/bjsports-2017-097608](https://doi.org/10.1136/bjsports-2017-097608)
- Mamerow and colleagues, Journal of Nutrition, 2014, randomised crossover trial in eight adults: 24-hour muscle protein synthesis was about 25 percent higher when 90 g of protein was spread evenly over three meals than when skewed toward dinner. The contrary finding: eight people, one week, animal protein. [doi.org/10.3945/jn.113.185280](https://doi.org/10.3945/jn.113.185280)
- Hevia-Larraín and colleagues, Sports Medicine, 2021, randomised trial of 38 young men over twelve weeks: leg lean mass and strength gains did not differ between a high-protein plant-based diet and a protein-matched omnivorous diet. The contrary finding: both groups were fed 1.6 g per kg, so it says nothing about plant diets that fall short of that, and the participants were young men. [doi.org/10.1007/s40279-021-01434-9](https://doi.org/10.1007/s40279-021-01434-9)

## Questions women ask

**Is 1.6 g per kg too much for my kidneys?** Not for healthy kidneys; the trials above ran at that level without harm. Kidney disease is a different conversation, with a clinician.

**Do I have to combine proteins at every meal?** Across the day is enough. A legume and a grain somewhere in the same day covers it.

**What about the days I do not train?** The same. Muscle is built in the 48 hours after a session, which is most of the week.