The official US Recommended Dietary Allowance (RDA) for protein is 0.36 grams per pound of body weight — about 60 g/day for a 170-lb adult. This number has confused a generation of fitness-focused people. It was set to prevent deficiency, not to optimize muscle, performance, or body composition. The actual target for most active adults is roughly twice the RDA. Here is the current research-backed range.

The RDA vs the research consensus

The 0.36 g/lb (0.8 g/kg) RDA was set in 1980 to prevent protein deficiency — the threshold below which healthy adults lose lean body mass over time. It is a floor, not a target. It is based on nitrogen balance studies in sedentary adults using 1970s methodology.

Modern research (particularly the 2017 International Society of Sports Nutrition position statement and subsequent meta-analyses) suggests:

  • Sedentary adults: 0.5-0.7 g/lb for general health
  • Recreationally active: 0.7-0.9 g/lb
  • Active with muscle-building goals: 0.8-1.0 g/lb
  • Active adults over 65: 0.7-0.9 g/lb (higher than RDA to combat sarcopenia)
  • Diet phase (calorie deficit): 0.9-1.2 g/lb to preserve muscle

For most active adults, 0.8 g per lb of body weight per day is a useful single target. A 170-lb person lands at 136 g/day. A 140-lb person lands at 112 g/day. These are substantially more than the RDA but supported by strong evidence for better body composition outcomes.

Why more than RDA?

Protein serves several functions that become more demanding in active lifestyles:

  1. Muscle protein synthesis (MPS). Training damages muscle fibers and triggers repair. Repair requires amino acid availability. Higher protein intake supports higher MPS, especially after training.
  2. Satiety. Protein is the most filling macro per calorie. Higher protein diets are easier to adhere to during weight loss.
  3. Thermic effect of food. About 25% of protein calories are burned in digestion (vs 5-10% for carbs, 0-3% for fat). 200 g of protein “costs” about 200 calories to digest.
  4. Muscle preservation in a deficit. Without adequate protein, weight-loss diets lose significant muscle — changing body composition for the worse.
  5. Aging. Older adults have “anabolic resistance” — they require more protein per meal to trigger the same MPS as a younger person.

Is there an upper limit?

For healthy adults with normal kidney function, there is no evidence that high protein intake (up to 1.5 g/lb) causes harm. The “protein damages kidneys” concern comes from studies of people with pre-existing kidney disease — in whom high protein does accelerate decline. In healthy kidneys, high protein does not cause disease.

However, most people plateau in benefit around 0.8-1.0 g/lb. Going from 0.8 to 1.2 g/lb rarely produces meaningful additional body composition changes. It also gets harder to hit practically — you have to make room for it, potentially at the expense of carbs and fat.

Extreme protein intakes (2+ g/lb) are common in bodybuilding culture but have no research support for natural trainees. Beyond 1.0 g/lb, extra protein mostly becomes expensive urine.

Protein distribution throughout the day

Total daily protein matters most. But distribution matters second-most. Research suggests better outcomes when protein is spread across 3-5 meals rather than consumed in one or two large doses.

Each meal seems to have a maximum anabolic response around 30-40 g of protein for most adults (higher for larger people, higher for older people). Beyond that per-meal amount, the extra protein is still useful but its contribution to MPS tapers off.

Practical target: 4 meals per day, each with 30-40 g protein. A 170-lb person hitting 140 g total would eat:

  • Breakfast: 35 g (e.g., 4 eggs + Greek yogurt)
  • Lunch: 40 g (e.g., 5 oz chicken breast + beans)
  • Dinner: 40 g (e.g., 6 oz salmon + quinoa)
  • Snack: 25 g (e.g., protein shake + handful of nuts)

Protein sources and quality

Protein sources differ in digestibility, amino acid profile, and practical density.

High-quality complete proteins (all essential amino acids)

  • Lean meats (chicken breast, turkey, lean beef, pork loin): ~25 g per 4 oz
  • Fish (salmon, tuna, cod, tilapia): ~25 g per 4 oz
  • Eggs: ~6 g per egg
  • Greek yogurt (plain, non-fat): ~15-20 g per cup
  • Cottage cheese: ~25 g per cup
  • Milk: ~8 g per cup
  • Whey protein powder: ~20-25 g per scoop

Plant-based proteins (most are incomplete individually but complete in combinations)

  • Tofu: ~20 g per cup
  • Tempeh: ~31 g per cup
  • Lentils: ~18 g per cup cooked
  • Chickpeas: ~15 g per cup cooked
  • Edamame: ~17 g per cup
  • Seitan: ~25 g per 3 oz (highest density among plant foods)
  • Quinoa: ~8 g per cup cooked (complete protein, rare among plants)

Plant-based eaters can easily hit protein targets by combining sources and eating larger portions. Tofu, tempeh, seitan, and legumes are the workhorses. Plant protein powders (pea, rice, hemp) fill gaps.

Do protein shakes count?

Whey, casein, and plant protein powders are legitimate protein sources. They are not magic, but they are not inferior either. For people struggling to hit daily protein targets through whole foods (e.g., small appetites, busy schedules, post-workout convenience), protein powder is a useful tool.

Aim for most protein from whole foods (fiber, micronutrients, chewing satiety) and use powder as a supplement for 1-2 servings per day if needed.

What about older adults?

Adults over 65 have “anabolic resistance” — their muscles require more protein per meal to trigger the same MPS as younger adults. The consensus recommendation for older adults is:

  • 0.54-0.73 g/lb daily (1.2-1.6 g/kg)
  • At least 30 g protein per meal (higher than younger targets)
  • Especially important to hit protein at breakfast (often the lowest-protein meal in older adults)

Sarcopenia (age-related muscle loss) affects up to 30% of adults over 60 and is a major driver of falls, disability, and mortality. Protein intake combined with resistance training is the single most effective intervention.

Practical hitting the target

The easiest way to hit 140 g protein: include a protein source at every meal and snack.

  • Every breakfast: 25-35 g (eggs, Greek yogurt, cottage cheese, protein oatmeal)
  • Every lunch: 35-45 g (chicken, fish, lean beef, tofu, legumes)
  • Every dinner: 35-45 g (same options)
  • One snack with protein: 15-25 g (shake, jerky, nuts + yogurt, cottage cheese)

If you only eat protein at one meal per day, you will struggle to hit any reasonable target and will miss the distribution benefit.

Set your target

Our macro calculator returns a personalized protein target based on weight, activity, and goal. Start at 0.8 g/lb for most people, 1.0 g/lb if cutting or building, adjust based on training progress over 4-6 weeks. The specific number matters less than consistency — a daily 130 g target hit 6 out of 7 days beats a daily 150 g target hit 3 out of 7. Aim for what you will actually eat.