Many people begin asking questions about protein in their 30s and 40s.
Energy feels different. Recovery after exercise seems to take longer. Body composition subtly shifts. At the same time, headlines suggest that protein needs increase with age while rarely explaining why.
To bring clarity to the conversation, London-based dietitian Reema Pillai of Dietitian Fit & Co is here to unpack what changes after 35, what age-related anabolic resistance really means, and how to think about dietary protein requirements without turning ageing into something to fear.
Why Do Protein Needs Change as We Age?
Age-related physiological change does not begin at retirement. In fact, subtle shifts can begin much earlier.
“One of the biggest misconceptions,” Reema explains, “is that muscle mass loss only happens much later in life. In reality, lean muscle maintenance can begin trending downwards even from our 30s.”
This doesn’t mean there’s a sudden decline. Instead, there can be a gradual change in nutrient efficiency, or how effectively your body uses what you consume.
Small changes over time
In our 30s and 40s, several factors begin to influence how the body responds to protein. There might be:
- slight reductions in muscle protein synthesis
- lifestyle shifts such as less daily movement or more stress
- changes in training intensity
- hormonal changes (not limited to menopause)
- periods of illness or inactivity
“Year to year, these changes are very small,” says Reema. “But over decades, they accumulate. The body doesn’t suddenly stop responding to protein, it just becomes slightly more selective.”
This selectivity is part of what researchers describe as age-related anabolic resistance or the reduced sensitivity of skeletal muscle to protein and exercise. It’s therefore important to recognise that to maintain muscle, your protein requirements may change.
What Happens to Muscle Maintenance After 35?
Muscle tissue is not static. The tissues are part of an ongoing cycle of breakdown and rebuilding. This process is governed by muscle protein synthesis.
When the rebuilding side of that cycle becomes slightly less responsive, it’s often related to anabolic resistance.
Understanding anabolic resistance
Reema explains it simply: “Earlier in life, moderate protein intake gives a strong muscle response. From our 30s and 40s onwards, anabolic resistance means that the same protein intake produces a weaker response, so more stimulus is needed to get a similar effect.”
The stimulus can come from:
- consistent, adequate dietary protein
- resistance or strength training
- sufficient total energy intake
- good quality sleep and recovery periods
- Without adequate stimulus, muscle breakdown can outpace rebuilding over time.
But this isn’t about aesthetics or bodybuilding. Reema reminds us that lean muscle maintenance influences:
- recovery and repair after exercise
- resilience during illness
- connective tissue strength
- metabolic health and steady blood sugar levels
- long-term physical independence
Everyday implications
From your mid-30s onwards, Reema says you might notice slower recovery after workouts.
“If someone is ill or inactive for a period,” Reema adds, “they may experience slightly more muscle loss than they would have earlier in life. That’s why having a structured eating pattern becomes more beneficial over time.”
The message isn’t fear-based. It’s practical: as you get older, consistency matters more.
How Do Protein Requirements Shift With Age?
Dietary protein recommendations can be based on preventing deficiency rather than optimising muscle health in midlife and beyond.
At 25, the body is more sensitive to protein and exercise, recovery is faster, and daily movement is often higher.
“Later in life,” Reema reminds us, “the same intake of protein and exercise may provide lower stimulation signals and slower recovery. So, the emphasis needs to shift toward consistency and intentionality.”
From growth to maintenance
In your 20s, protein may be framed around growth or performance. After 35, the focus shifts. “Instead of thinking about building more muscle,” says Reema, “it can be more helpful to think about protecting and maintaining what you have.”
This isn’t about dramatically increasing intake, but ensuring that dietary protein still provides sufficient stimulus.
Will Eating Extra Protein Help?
Whenever protein needs are discussed, the conversation can quickly turn into “more is better.” But Reema says that shouldn’t be the goal.
“More doesn’t always equal better,” Reema emphasises. “We don’t want protein intake to displace other nutrients or lead to unnecessary calorie intake.”
There is a ceiling to how much protein the body can effectively use at one time for muscle protein synthesis. Excess protein beyond physiological needs may be:
- used for energy
- stored
- converted
- excreted
Eating far beyond your needs cannot override anabolic resistance.
Context matters
Protein does not work in isolation. “If overall energy intake is too low, protein may be diverted to produce energy instead of supporting muscle protein synthesis. That’s why chronic dieting or under-fuelling can lead to muscle loss even if protein intake seems high,” Reema explains.
Other factors influencing protein efficiency include:
- adequate carbohydrate intake for exercise levels
- sleep quality
- stress levels
- illness or injury
During high stress or illness, protein turnover increases, meaning needs may temporarily rise.
Find out more in our article: How does protein interact with gut health, digestion and nutrient absorption?
Quality and leucine
Not all proteins stimulate muscle protein synthesis equally.
Certain essential amino acids, particularly leucine, help activate the muscle-building signal. As we age, the leucine threshold required to trigger this signal increases slightly.
Adequate essential amino acids can be found in high-quality complete proteins including:
- Meat
- Poultry
- Dairy
- Eggs
- Soy
- Pea protein
The whey protein powders from The Organic Protein Co. are high-quality complete proteins that contain all essential amino acids including leucine.
Why Do Consistency and Distribution Matter as You Get Older?
An overlooked aspect of dietary protein requirements is protein distribution.
Before exploring this, it’s important to understand that muscle protein synthesis peaks within a few hours of eating protein.
Many people naturally follow an eating pattern that means protein is heavily skewed towards dinner, giving the body one large protein stimulus and long gaps without support.
Why even distribution matters
“Muscle protein synthesis works best with regular protein across the day,” Reema explains. “If someone eats very little protein at breakfast and lunch, then a protein-heavy evening meal, that distribution is less efficient.” As anabolic resistance increases, this inefficiency becomes more relevant.
Providing moderate protein stimulus multiple times per day:
- supports ongoing repair and maintenance
- aligns with natural tissue breakdown cycles
- improves overall nutrient efficiency
“The body is constantly breaking down and rebuilding tissue,” Reema adds. “Protein is the signal to start that repair, and the signal works best if it happens multiple times throughout the day.”
This doesn’t require strict schedules. It just means avoiding long protein gaps.
How Does Protein Support Resilience as the Body Changes?
“As we get older, protein becomes part of a resilience strategy,” Reema says. “It helps the body retain muscle mass during high-stress periods and adapt better to training.”
This is not about chasing numbers or grams. It’s about creating a stable, supportive environment for the body.
Discover more in our article: Why don’t some people feel the benefits of protein straight away – and how can that be fixed?
What Should Someone in Their Late 30s or 40s Focus On?
Reema’s advice is calm and practical: “Start being more intentional with your protein intake and include a protein source regularly throughout the day. Make sure your first meal contains protein after the overnight fast. Pair protein with resistance training and ensure you’re meeting your overall calorie and nutrient needs.”
This focus can mean making the following part of your lifestyle:
- fibre from fruits, vegetables, and whole grains
- healthy fats from nuts, seeds, or olive oil
- regular strength training (2-4 times per week where appropriate)
- adequate recovery
The Takeaway
Protein requirements after 35 are not about fear, restriction, or excess.
They reflect:
- changes in muscle protein synthesis
- gradual anabolic resistance
- shifts in nutrient efficiency
- the importance of lean muscle maintenance
The body still responds to protein; it simply needs clearer signals from high-quality food sources, consistent eating patterns, and a supportive lifestyle.
Find out more: read our article about healthy ageing, strength and independence later in life.
