Protein tends to be framed as a fitness topic — something athletes track, something in the small print on protein bars. But protein is foundational to almost every process in the human body, and the evidence is increasingly clear that many women — especially those over 40, those who are pregnant or breastfeeding, and those eating plant-forward diets — are chronically underconsuming it.

This is not about eating more chicken. It is about understanding what protein actually does, how much your body genuinely needs across different life stages, and how to build it into meals in ways that feel natural rather than effortful.

“Protein is not a supplement. It is the structural material of your entire body — and most women are building that structure with an inadequate supply.”

— Mama Sara

What Protein Actually Does

Protein is made up of amino acids, nine of which are “essential” — meaning the body cannot make them, so they must come from food. These amino acids are the raw material for:

  • Muscle tissue. Every muscle in your body is built from protein. Without adequate intake, the body cannot repair or maintain muscle mass, which begins to decline from the mid-30s onward.
  • Hormones. Insulin, thyroid hormones, growth hormone, and many others are protein-based. Inadequate protein directly affects hormonal regulation.
  • Enzymes. Every biochemical reaction in the body — digestion, detoxification, energy production — is catalysed by protein-based enzymes.
  • Immune function. Antibodies are proteins. A low-protein diet impairs the immune response, which is one reason illness and slow recovery can be signs of inadequate intake.
  • Neurotransmitters. Serotonin, dopamine, and melatonin are made from amino acids. Tryptophan (from protein) is the precursor to serotonin and melatonin — connecting adequate protein intake to mood and sleep.
  • Satiety. Protein is the most satiating macronutrient. It slows gastric emptying and reduces appetite hormones more effectively than carbohydrates or fat. A protein-rich breakfast is one of the most reliable ways to reduce cravings throughout the day.

How Much Protein Do You Actually Need?

The standard UK reference nutrient intake (RNI) is 0.75g of protein per kilogram of body weight per day — for a 65kg woman, that is roughly 49g. This figure is often cited as the target. It is not. It is the minimum required to prevent deficiency in a sedentary person. Most researchers studying optimal health outcomes, muscle preservation, and satiety now recommend significantly more.

General active adult

1.2–1.6g per kg of body weight daily. For a 65kg woman: 78–104g. This is the range most associated with healthy body composition, good satiety, and immune support.

Over 40

1.4–1.8g per kg. Muscle protein synthesis becomes less efficient with age. Higher intake partially compensates for this. Sarcopenia (age-related muscle loss) is strongly correlated with low protein intake.

Pregnant

+25g above baseline, particularly in the second and third trimesters when fetal tissue is growing rapidly. Many women do not adjust their protein intake during pregnancy despite substantially higher need.

Breastfeeding

+20g above baseline. Milk production requires protein, and many breastfeeding women are exhausted in part because of the drain on maternal nutrient stores.

Perimenopause & menopause

1.6–2.0g per kg. Oestrogen supports muscle protein synthesis; as it declines, higher protein intake (alongside resistance exercise) is the primary nutritional lever for preserving muscle mass and bone density.

Plant-based diets

10–20% higher than meat-eaters to account for lower bioavailability of plant protein and incomplete amino acid profiles in individual sources. Variety and combination matter.

Spreading Protein Through the Day

How you distribute protein matters almost as much as total intake. The body can only use roughly 25–40g of protein for muscle protein synthesis at a single sitting — beyond that, the excess is used for energy or excreted. Eating 80g of protein in one meal and very little for the rest of the day is far less effective than spreading intake evenly.

The practical implication: aim for a meaningful source of protein at every meal, not just dinner. Breakfast is where most women fall short. A glass of orange juice and a piece of toast provides almost no protein. Eggs, Greek yoghurt, smoked salmon, or adding a handful of nuts or seeds transforms the same meal into one that supports satiety and muscle maintenance through the morning.

Protein targets made practical

If you weigh around 65kg and aim for 1.4g/kg, you need roughly 91g per day. Split across three meals: that is about 30g per meal. One large egg contains 6g. A tin of sardines: 22g. 150g Greek yoghurt: 15g. 100g chicken breast: 31g. A cup of cooked lentils: 18g. Two tablespoons of peanut butter: 8g. It adds up quickly when you make protein intentional at every meal.

Best Sources of Protein for Women

Animal Sources (complete proteins)

Animal proteins contain all nine essential amino acids in roughly the proportions the body needs. They also tend to have higher bioavailability — meaning a greater proportion is actually absorbed and used.

  • Eggs: Often called the gold standard of protein. Highly bioavailable, versatile, affordable, and rich in choline (important for brain health and pregnancy). Whole eggs, not just whites.
  • Oily fish: Sardines, mackerel, salmon, and trout provide protein alongside omega-3 fatty acids. Tinned sardines are one of the most nutrient-dense and affordable protein sources available.
  • Greek yoghurt: Around 10g of protein per 100g, plus calcium, B12, and probiotics. Full-fat versions are more satiating and avoid the additives often present in low-fat alternatives.
  • Chicken and turkey: High protein, lean, and versatile. Prioritise quality — organic or free-range makes a meaningful difference to omega-3 content and welfare.
  • Meat (red): Grass-fed beef and lamb provide protein alongside iron, zinc, and B12. The iron in red meat (haem iron) is significantly better absorbed than plant sources — important for women of menstruating age, who have higher iron requirements.

Plant Sources (building complete profiles)

Plant proteins are not “inferior” — they simply have different amino acid profiles. Eating a variety of plant proteins across the day covers all essential amino acids without needing to pair them at every meal.

  • Lentils: Around 18g per cooked cup, plus iron, folate, and fibre. One of the most nutritionally valuable foods available at any price point.
  • Chickpeas and beans: 14–18g per cooked cup. Chickpeas are particularly high in the amino acid lysine, which is limited in grains.
  • Edamame and tempeh: Among the few plant sources that are genuinely complete proteins. Tempeh also provides fermentation benefits for gut health.
  • Tofu: Around 8–17g per 100g depending on firmness. Firm tofu is considerably higher. A useful protein base for plant-forward meals.
  • Hemp seeds: A complete protein. Add 3 tablespoons to a smoothie, porridge, or salad for 10g of protein without changing the meal substantially.
  • Pumpkin seeds: 9g per 30g serving. One of the highest-protein seeds and also rich in magnesium and zinc.

A Note on Iron and Protein Together

Women who menstruate have iron requirements nearly double those of men. Iron deficiency is the most common nutritional deficiency in women globally and causes fatigue, poor concentration, and reduced immunity — symptoms often attributed to other causes. The best sources of absorbable iron are also protein-rich: red meat, sardines, eggs, lentils. Eating vitamin C alongside plant iron sources (a squeeze of lemon on lentils, tomatoes with beans) significantly improves absorption. Avoiding tea and coffee with meals reduces the tannins that inhibit it.

Simple ways to add protein without a full recipe overhaul
  • Add two eggs to breakfast, whatever else you are having
  • Stir Greek yoghurt into porridge or use as a base for dressings
  • Keep tinned fish (sardines, mackerel, salmon) for quick lunches
  • Add a handful of hemp or pumpkin seeds to salads, soups, or smoothies
  • Swap rice for lentils or quinoa as a base one or two nights a week
  • Snack on a boiled egg, a small handful of nuts, or some cheese rather than crackers alone

The Protein Timing Around Exercise

If you exercise — particularly resistance training or high-intensity cardio — protein timing becomes more relevant. Consuming 20–30g of protein within a couple of hours of exercise supports muscle repair and adaptation. This does not need to be a protein shake. A poached egg on toast, a Greek yoghurt with fruit, or a portion of fish with rice are all effective.

For women in perimenopause and beyond, combining adequate protein intake with some form of resistance exercise — even light weights or bodyweight work — is the most evidence-backed approach for preserving muscle, supporting bone density, and maintaining metabolic health through the hormonal transition.

Protein is not complicated. It does not require tracking apps, expensive powders, or eating more than you want to. It requires consistent attention: a protein source at breakfast, a protein source at lunch, a protein source at dinner, and a diet that genuinely varies its sources rather than defaulting to the same two or three. Over time, that consistency adds up to a body that has the raw material it needs to function, repair, and feel well.