Starting at age 35, the body begins to change quietly. It’s not something we notice overnight, but gradually hormonal, metabolic, and structural changes occur that affect both women and men. One of the most relevant and least discussed changes is the progressive loss of muscle mass.
Maintaining muscle mass is not just an aesthetic issue. It’s a key factor for metabolic health, strength, injury prevention, future mobility, and quality of life. And this is where protein plays a fundamental role.
WHAT HAPPENS IN THE BODY AFTER 35
From this stage on, a natural process called sarcopenia begins, which involves the gradual loss of muscle mass and strength. This process can speed up if there isn’t enough physical stimulus or if the diet doesn’t meet protein needs.
In women, hormonal changes approaching perimenopause can also influence body composition. In men, the gradual decrease in testosterone can also affect muscle mass. In both cases, the result can be the same: more difficulty maintaining strength, a greater tendency to accumulate fat, and slower recovery after exercise.
The good news is that this process is neither inevitable nor irreversible. It can be prevented and slowed down with two basic pillars: strength training and sufficient protein intake.
WHY PROTEIN IS SO IMPORTANT
Protein is the macronutrient responsible for building and repairing tissues, including muscle tissue. Every time we train, especially strength training, we create a stimulus that “breaks” muscle fibers at a microscopic level. For the body to repair and strengthen them, it needs amino acids, which are the building blocks of protein.
After 35, the body becomes less efficient at using consumed protein to synthesize new muscle mass. This means women and men may need a slightly higher amount than in earlier stages to get the same effect.
It’s not about consuming large amounts without control, but about adjusting quality and distribution throughout the day.
HOW MUCH PROTEIN DO WE REALLY NEED
General recommendations for the adult population are usually set at 0.8 grams per kilogram of body weight per day. However, various studies in nutrition and healthy aging suggest that after ages 35–40, an intake between 1.2 and 1.6 grams per kilogram may be more appropriate, especially if regular physical activity is performed.
For example, an active 60 kg woman might need between 72 and 96 grams of protein per day. An 80 kg man might require between 96 and 128 grams.
What matters most is not only the total amount, but how it’s distributed. Spreading protein across different meals supports muscle protein synthesis more efficiently than concentrating it only at dinner.
PROTEIN AT EVERY MEAL: A SMART STRATEGY
Many people—women and men—tend to eat low-protein breakfasts (coffee, toast, pastries) and concentrate most of their intake at lunch or dinner. This pattern does not support muscle building.
A more effective strategy would be to include a protein source at each main meal:
- Breakfast: plain yogurt, eggs, fresh cheese, tofu, or plant-based protein
- Lunch: legumes, fish, lean meat, eggs, or plant-based combinations.
- Dinner: lighter options but with enough protein.
- Snacks if needed: nuts, yogurt, hummus.
The goal is to reach approximately 20–40 grams of protein per meal, depending on body weight and activity level.
PROTEIN QUALITY: ANIMAL AND PLANT
Both women and men can meet their needs with animal, plant, or combined sources. Animal proteins (eggs, fish, meat, dairy) contain all essential amino acids in optimal proportions. Plant proteins (legumes, nuts, seeds, whole grains) may need to be combined to get a complete profile. What matters is variety. A diverse diet not only supports muscle mass but also gut and metabolic health.
PROTEIN AND METABOLISM: BEYOND MUSCLE
Maintaining muscle mass also directly affects metabolism. Muscle is a metabolically active tissue: the more muscle mass we keep, the higher our resting energy expenditure.
This means caring about protein intake after 35 not only helps maintain strength and functionality, but also supports body weight control and glucose stability. In addition, good muscle mass protects against falls later in life, improves posture, and reduces joint pain caused by structural weakness.
THE ROLE OF STRENGTH TRAINING
It’s important to emphasize that protein alone does not build muscle mass. It needs a stimulus. Strength training—adapted to each person—is the signal that tells the body it must preserve and develop muscle.
It’s not necessary to lift heavy weights. Bodyweight exercises, resistance bands, or guided gym training can be enough if done progressively and consistently. The combination of strength + adequate protein is the most effective formula to preserve muscle mass in women and men after 35.