How Much Protein Do You Really Need? An Evidence-Based Answer

The Government Number Is Wrong for Most People

The official Recommended Dietary Allowance (RDA) for protein is 0.8 g/kg of body weight. This number is the minimum to prevent deficiency in a sedentary person — not the optimum for someone who exercises, wants to lose fat, or is over 50.

Across two decades of randomized trials, the optimum range for active adults is closer to 1.6–2.2 g/kg of body weight.^[1] That is roughly 2–3× the RDA.

What Protein Actually Does

Protein has four jobs that matter for your physique and your day:

1. Muscle preservation and growth. Amino acids are the bricks. Without enough, muscle protein synthesis can't keep up with breakdown.
2. Satiety. Gram-for-gram, protein keeps you fuller than carbs or fat. That makes calorie control dramatically easier.
3. Thermic effect. About 20–30% of protein's calories are used in digestion (vs. ~5% for fat and ~10% for carbs). High-protein meals literally burn more.
4. Metabolic health. Adequate protein supports stable blood sugar, hormone production, and immune function.

The Numbers, By Goal

Weight loss

When you eat in a deficit, the body looks for fuel — and it will burn muscle if you let it. Protein protects muscle.

• Target: 1.8–2.2 g/kg per day
• 70 kg adult: 125–155 g protein/day
• 85 kg adult: 150–185 g protein/day

The leaner you get, the higher you push within this range.^[3]

Muscle gain

In a calorie surplus, more protein doesn't automatically mean more muscle, but underdosing protein definitely blunts results.

• Target: 1.6–2.0 g/kg per day
• Bias toward the higher end if you're an experienced lifter or older

Recomp (lose fat, gain muscle)

Same as weight loss: keep protein high. 1.8–2.2 g/kg.

Endurance athletes

Often underrated. Endurance training increases protein needs, particularly around training.

• Target: 1.4–1.8 g/kg per day

Older adults (50+)

Sarcopenia — age-related muscle loss — accelerates without enough protein. The RDA is especially wrong for this group.

• Target: 1.2–1.6 g/kg per day, even sedentary

How to Distribute Protein

Total daily protein matters most, but per-meal dosing has a second-order effect.

• 3–5 meals per day of 25–40 g protein each
• 0.4 g/kg per meal is the dose that maximizes muscle protein synthesis
• A pre-bed protein meal (cottage cheese, casein, Greek yogurt) helps overnight recovery for trained athletes

Highest-Density Protein Sources

Food	Protein per 100g	Calories
Turkey breast	30 g	135
Chicken breast	31 g	165
Tuna (canned)	25 g	116
Cottage cheese	11 g	98
Greek yogurt	10 g	59
Shrimp	24 g	99
Tofu	8 g	76
Lentils	9 g	116
Edamame	12 g	121

Track your calories with KairoFree on the App Store

Common Myths

"Too much protein is bad for your kidneys"

In healthy people, no. Studies up to 3.4 g/kg have shown no harm to kidney function.^[2] People with existing kidney disease should follow their doctor's plan — but for the general population, the kidney myth is just that.

"You can only absorb 30 g of protein at a time"

False. The body absorbs essentially all the protein you eat. The "30 g cap" refers to per-meal muscle protein synthesis stimulation — not total absorption. Eating 60 g at one meal isn't wasted; the rest is used for other tissues, enzymes, and hormones.

"Plant protein is incomplete"

Most individual plant foods have lower levels of one or two essential amino acids, but a varied diet that includes legumes, grains, nuts, and seeds easily covers all amino acid needs. Tofu, edamame, quinoa, and buckwheat are complete on their own.

Practical Daily Examples

Example: 70 kg active adult, 140 g protein target

• Breakfast: 200 g Greek yogurt + 30 g granola + berries → 24 g
• Lunch: 150 g grilled chicken breast + rice + vegetables → 47 g
• Snack: 200 g cottage cheese + apple → 22 g
• Dinner: 150 g salmon + sweet potato + spinach → 34 g
• Pre-bed: 1 scoop whey + milk → 30 g

Total: ~157 g. Distributed across 5 meals.

Conclusion

Protein is the single highest-leverage macro to dial in. If you take nothing else from this article: aim for 1.6–2.2 g/kg per day, spread across 3–5 meals, biased toward minimally processed sources. The change in your physique, energy, and hunger control will likely surprise you.

For the bigger picture, see our complete macronutrients guide.