Muscle isn’t just about aesthetics or strength. It’s a metabolic organ that influences your longevity, blood sugar regulation, recovery, and even immune resilience. But building muscle isn’t just about lifting weights or hitting your daily protein target. It’s about timing, consistency, and understanding how your body responds to stress and recovery.
In this episode of The Dr. Gabrielle Lyon Podcast, renowned muscle-metabolism scientist Dr. Nick Burd explores the complex drivers of anabolic resistance, particularly in obesity. He shares how muscle quality (not just quantity), training consistency, and protein efficiency shape our ability to build and maintain muscle. You’ll learn why some people don’t respond well to protein or exercise, why resistance training is essential, and how whole foods and the food matrix can influence nutrient absorption and muscle remodeling.
Whether you’re new to strength training or a seasoned athlete trying to preserve muscle with age, this conversation is your roadmap to results.
Protein Is a Signal, Not Just a Nutrient
Many people view protein as fuel, but Dr. Burd encourages us to think of protein as a signal. When you eat protein, especially after exercise, you’re sending a message to your muscles: grow, repair, rebuild. That’s the process of muscle protein synthesis (MPS), and it’s essential for preserving lean mass.
The post-exercise window amplifies the body’s responsiveness to protein. Research shows that 20–40 grams of high-quality protein per meal is typically enough to maximize this anabolic response. Going beyond that doesn’t necessarily build more muscle — it often just leads to amino acid oxidation and waste.
This brings us to an important concept Dr. Burd emphasizes: protein efficacy. Rather than chasing massive protein doses, the focus should be on how effectively your body uses the protein you eat. This efficacy depends on digestion, amino acid absorption, and how well your protein intake is matched to your body’s needs Protein efficacy.
A 2023 paper coauthored by Dr. Burd emphasizes this distinction between optimal vs. maximal protein intake. The goal, he argues, should be efficient protein use, especially from high-quality, whole-food sources that promote better digestion and utilization. In his eyes, more is not necessarily better.
The focus on high-quality protein is important because recent studies show that exercise itself may temporarily impair protein digestion and absorption. After training, the gut lining can suffer micro-damage, slowing the rate of amino acid appearance in the blood. This means even if you eat the right foods, your body might not absorb them as efficiently right after your workout.
That said, there are valid discussions around this topic. For instance, other research has shown that consuming larger single doses of protein (like 70 grams vs. 40 grams) can still increase whole-body protein synthesis and net protein balance, even if MPS is already maximized. It’s also worth noting that MPS accounts for just 20–30% of total body protein turnover.
And then there’s individuality. We simply can’t know how much protein for any given person is “optimal.” Protein needs vary across age, activity, body composition, and metabolic health. While lower amounts may support MPS in younger, healthy adults, I continue to recommend a range of 1.6 to 2.2 g/kg/day, as this likely provides the most benefit for the majority of individuals, especially those aiming to optimize performance, recovery, and healthy aging.
Resistance Training Drives the Adaptation
Protein intake is only half the equation. As Dr. Burd explains, resistance training is what activates the muscle’s demand for growth. Without that physical signal — the stress placed on muscle fibers through mechanical tension — there’s no real reason for your body to build or preserve lean tissue.
The act of lifting weights (or using bodyweight, bands, or machines) initiates a cascade of molecular events inside muscle cells. These anabolic signals create a heightened state of sensitivity to amino acids. This means that protein consumed after training becomes significantly more effective at supporting MPS than it would be at rest.
Think of training as opening the door, and protein as walking through it.
This is probably the single most important thing you can do to build and maintain muscle. In fact, research shows that increases in muscle mass and strength occur across a wide range of protein intakes so long as participants are engaged in a consistent resistance training program.
The training itself is the driver. Protein influences the outcome, but it doesn’t initiate the process.
That’s why we think of protein as a modulator rather than a magic bullet. It shapes the body’s response to training, enhances recovery, and accelerates gains, but only when the training signal is already in place.
Dr. Burd also introduces the concept of the variable responder. Some people build muscle quickly. Others progress more slowly, even with the same training and nutrition. Body fat and dietary responses also differ widely, shaped by genetics, age, metabolic flexibility, and other individual traits.
It’s a powerful reminder that personalization matters, but so does persistence. If you’re not seeing results, it doesn’t necessarily mean something is wrong. It may mean your body simply needs more time or a slight adjustment in training volume, intensity, or recovery. What matters most is that you continue. The consistency of stimulus is what drives adaptation over time.
Your Muscle Is Listening All Day
One of the most practical takeaways from this episode is the importance of even protein distribution across meals.
Many people eat very little protein at breakfast, moderate amounts at lunch, and then overcompensate with a large serving at dinner. But Dr. Burd’s research shows that MPS is triggered on a per-meal basis, meaning if your earlier meals fall short, your body misses out on anabolic opportunities.
One seminal study illustrates this beautifully. During a 12-hour post-exercise period, the greatest increases in MPS were seen when participants consumed 20 grams of whey protein every three hours, as compared to 10 grams every 1.5 hours or 40 grams every six hours. This shows that you want to eat enough protein at each meal while also eating frequently enough to keep MPS humming along.
That being said, a 2025 randomized controlled trial led by Dr. Burd found no significant difference in MPS between balanced and unbalanced protein distributions, as long as total daily intake (~1.14 g/kg) was met. It also found that vegan and omnivorous diets supported MPS equally well when matched for protein quantity and quality.
These findings suggest that total daily protein is the primary driver of muscle gain, while per-meal distribution plays a supportive, but still meaningful, role. While the trial was short-term, it does challenge rigid beliefs around meal timing and plant protein inferiority.
Still, over time, even small differences in per-meal MPS may compound into measurable changes in muscle mass. So while we don’t need to obsess, we do encourage a general pattern of 30–40 grams of high-quality protein at each main meal whenever possible.
Anabolic Resistance: The Hidden Barrier in Aging and Obesity
One topic that deserves special attention is anabolic resistance.
This is a physiological phenomenon where the muscle becomes less responsive to the normal anabolic signals provided by protein intake and exercise. It tends to increase with age, but it’s especially pronounced in individuals with overweight or obesity, and may contribute to the difficulty many people face when trying to gain muscle or lose fat.
Several studies have shown that obese individuals experience blunted MPS responses after consuming high-quality protein meals. For example, one study found that after eating 36 grams of pork, healthy-weight adults saw a 1.6-fold increase in MPS while overweight and obese adults showed no significant increase, despite having identical amino acid availability.
Building on this, a follow-up study demonstrated that even adding resistance exercise failed to enhance the anabolic response in people with obesity. In normal-weight adults, the combination of resistance exercise and protein ingestion significantly increased MPS in the exercised leg. But in those with obesity, exercise did not augment MPS beyond the response to protein alone.
Why does this happen? The mechanisms are complex and include:
- Chronic low-grade inflammation that interferes with muscle signaling
- Impaired insulin signaling and nutrient delivery
- Altered mTORC1 activity, a key muscle growth pathway
- Reduced muscle capillarization, limiting amino acid transport
- Elevated baseline anabolic signaling, which may blunt further stimulation
The takeaway is that protein quality and quantity still matter, but they’re not always enough. In these cases, regular resistance training, strategic nutrient timing, and inflammation management are critical to restoring anabolic sensitivity.
The Food Matrix:
This is where Dr. Burd’s discussion of the food matrix becomes interesting and relevant. Whole foods aren’t just bags of amino acids; they contain structure, cofactors, and nutrients that interact with the protein and amino acids to influence digestion and absorption.
Dr. Burd explains that while isolated protein sources like whey create a rapid spike in amino acid levels after a meal, this surge is often accompanied by increased amino acid oxidation, meaning more of the protein is wasted rather than used for muscle building. In contrast, whole foods produce a slower, more sustained release of amino acids, which may enhance utilization and reduce waste. For example, his team found that eating whole eggs stimulated a greater anabolic response than consuming the same amount of protein from egg whites alone, highlighting the importance of the food matrix in optimizing protein efficiency.
The plant vs. animal protein debate is a great example. We know that plant proteins are generally less anabolic than animal proteins due to lower digestibility, less complete amino acid profiles, and limiting amino acids. Eating animal protein is simply easier for obtaining adequate high-quality protein, but plant sources can make huge strides with a little effort. Plant-based protein powders are highly digestible and an easy way to boost protein intake, for example, due to the heavy processing.
Of course, resistance training remains the most potent stimulus for reversing anabolic resistance. It helps “re-sensitize” the muscle to protein, restoring its ability to grow and adapt.
Common Mistakes That Sabotage Muscle Growth
Dr. Burd and Dr. Lyon highlight the most common roadblocks to building muscle, especially among adults over 40:
- Low protein at breakfast
- Skipping meals or relying on snacks
- Doing too much cardio without enough strength work
- Training inconsistently or without progressive overload
- Focusing on supplements over food
Whether you eat animal or plant-based protein, whether you’re 25 or 65, your muscle is still capable of adapting. But you must send the right signals — consistently — through high-quality nutrition and regular resistance training.
Muscle is your metabolism, your stability, your glucose sink, and your resilience. It’s the organ of longevity, and the earlier you train it, the more future-proof your body becomes.
Action Checklist
Here’s your practical muscle-building checklist, now updated with science-backed insights:
- Aim for 0.7-1g of protein per pound of your goal body weight daily
- Eat 30–40g of high-quality protein per meal, spaced across 3–4 daily meals.
- Train with resistance at least 3x/week, with progressive overload
- Don’t skip breakfast, it’s a missed anabolic opportunity.
- Sleep 7–9 hours per night to enhance recovery and hormonal health.
- If using plant protein powders, consider protease enzyme blends to improve amino acid availability.
- Track your protein intake for a few days to spot gaps or timing issues
🎧 Listen to the full conversation with Dr. Nick Burd here → Why Muscle Doesn’t Respond: Protein Efficiency, Obesity & Resistance Training | Dr. Nick Burd
