🍗 Why 30g of Protein Per Meal Is More Than Just a Rule of Thumb

Dan Beck
Sep 30
2 min read

If you’ve been in the fitness world long enough, you’ve probably heard it: “You need 30 grams of protein per meal.” But where does that number actually come from? Is it real science, or just gym folklore?

Let’s pull back the curtain.

🔬 The Science Behind the Number

Protein isn’t just about total daily intake — it’s also about how much you eat per meal. Why? Because protein stimulates something called muscle protein synthesis (MPS) — the process your body uses to repair and build muscle tissue.

To maximally trigger MPS, research shows you need ~0.4 grams of protein per kilogram of bodyweight per meal (Aragon & Schoenfeld, 2013; Morton et al., 2018).

For a 150–180 lb. (68–82 kg) person, that works out to ~27–33 grams of protein per meal.
For someone heavier, it might push closer to 35–40 grams.

👉 That’s why “30 grams” stuck. It’s not magic — it’s math.

🧬 The Leucine Threshold

Protein quality matters, too. One key amino acid, leucine, acts as the “trigger” for muscle growth. To flip that switch, you need ~2.5–3 grams of leucine per meal.

Most high-quality proteins (chicken, beef, whey, eggs, fish) deliver this at 25–35 grams of protein.
Plant-based proteins may require more total grams to hit the same leucine threshold.

🍽️ Distribution Over the Day

It’s not just about hitting your total protein goal (though that’s priority #1). It’s also about how you spread it out.

Eating 30–40g of protein in 3–5 meals per day leads to better muscle retention and growth compared to loading it all at dinner.
As Dr. Layne Norton (popular science-based influencer) often points out: “Twenty grams per meal probably leaves gains on the table. Forty grams covers most people.”

👵 What About Older Adults?

As we age, our muscles become less sensitive to protein — a phenomenon called anabolic resistance.

Research suggests older adults may need closer to 35–40g per meal to maximally stimulate MPS.

⚡ Practical Takeaway

Here’s how to apply the science:

General population: Aim for 30g+ per meal to cover your bases.
Athletes & lifters: Push toward 35–40g per meal, especially if you’re heavier.
Older adults (50+): Target the higher end (35–40g) to overcome anabolic resistance.

🥡 How Simple Plan Fits

Every Simple Plan meal is built with this science in mind:

30g+ protein in every meal — no food math required.
Balanced carbs and fats to support recovery and energy.
Flexible pickup and delivery so hitting your nutrition goals feels effortless.

Whether you’re chasing muscle, strength, or just a healthier diet, the “30g rule” isn’t just a myth. It’s a practical shortcut grounded in real science.

✅ Bottom line: Think of protein in doses, not just totals. Hitting 30–40g per meal is one of the simplest, most effective habits you can lock in for your health and fitness.