📚 Part of our Weight Loss Guide — an evidence-based guide.
Protein is the macronutrient people argue about most and measure least. The official minimum is lower than the fitness industry claims and higher than most people actually eat — and, more importantly, the minimum was never designed to answer the question most people are really asking.
The official number, and what it actually means
The Recommended Dietary Allowance for adults is 0.8 grams per kilogram of body weight per day — about 0.36 grams per pound. For a 70 kg (154 lb) adult, roughly 56 grams.
Here is the part that gets lost. The RDA is the amount estimated to meet the needs of almost all healthy people to prevent deficiency. It is a floor, not a target, and it was never intended to describe the intake that best preserves muscle, supports ageing, or optimises anything.
Treating a deficiency-prevention threshold as an optimum is the single most common misreading in this area — and it runs in both directions, since the supplement industry then uses it as a straw man.
What the evidence supports beyond the minimum
Where higher intakes have real support:
During weight loss: roughly 1.2 to 1.6 g/kg. A calorie deficit costs muscle unless protein and resistance training protect it, and what you lose determines whether the loss lasts (why muscle decides). Protein is also the most satiating macronutrient, which makes the deficit survivable (why hunger happens).
Older adults: roughly 1.0 to 1.2 g/kg, and often more. This is the least appreciated point. Ageing muscle responds less to a given dose of protein — a phenomenon called anabolic resistance — so older people need more to achieve the same effect, at exactly the age when appetite and intake tend to fall. Combined with the muscle loss that drives much of midlife change (what changes after 50), this matters.
Building muscle with resistance training: roughly 1.6 g/kg, with meta-analyses finding little additional benefit beyond about 2.2 g/kg. Above that, more protein is not harmful for healthy people — it simply stops adding anything.
For most adults not in those categories, somewhere between 1.0 and 1.2 g/kg is a reasonable, unremarkable target.
Distribution matters more than people expect
Most people eat very little protein at breakfast, a moderate amount at lunch, and a large amount at dinner. Muscle protein synthesis responds to individual meals, so a skewed distribution wastes some of the protein you already eat.
Roughly 25 to 40 grams per meal, spread across the day, is more effective than the same total concentrated at night. In practice, breakfast is where nearly everyone has room — and a protein-rich first meal also reduces intake later in the day (why).
What 25 to 30 grams looks like
- 100 g (3.5 oz) cooked chicken breast — about 31 g
- 150 g (5 oz) Greek yoghurt — about 15 g
- 3 large eggs — about 19 g
- 100 g canned tuna — about 25 g
- 150 g cooked lentils — about 13 g
- 200 g firm tofu — about 23 g
- 30 g whey powder — about 24 g
- 250 ml milk — about 8 g
The practical lesson is that plant sources need larger portions or combination to reach the same numbers — not that they are inadequate.
Plant versus animal protein
Animal proteins are generally complete and more readily digested. Most single plant sources are lower in one or more essential amino acids — typically lysine in grains, methionine in legumes.
The old advice to carefully combine proteins at each meal has been abandoned; eating varied plant proteins across the day is sufficient. What remains true is that plant-based eaters should aim somewhat higher in total, and that soy, quinoa and buckwheat are complete on their own.
Does high protein damage your kidneys?
This deserves a direct answer because it circulates constantly.
In people with healthy kidneys, there is no good evidence that higher protein intake causes kidney damage. Controlled trials have not shown harm at the intakes discussed above. The belief originates from advice given to people who already have chronic kidney disease, where protein restriction is genuinely used — and that advice was then generalised to everyone, which is not what the evidence supports.
The real caveat: if you have existing kidney disease, protein intake is a medical decision. Do not raise it without your doctor.
Do you need a supplement?
No, for most people. Whey and other powders are a convenience, not a requirement — useful if you struggle to reach a target from food, particularly at breakfast or after training.
One thing worth knowing: protein powders are supplements, not regulated foods, and independent testing has repeatedly found products whose content differs from the label, sometimes with heavy metal contamination. Look for third-party certification such as NSF or Informed Sport.
When to talk to a doctor
Before increasing protein if you have chronic kidney disease, liver disease, or a history of kidney stones. Also worth a conversation if you are over 65 and losing weight, strength or muscle unintentionally — that combination points toward sarcopenia, where higher protein plus resistance training is part of the answer rather than a preference.
The honest bottom line
The RDA of 0.8 g/kg prevents deficiency; it does not describe an optimum. For most adults 1.0 to 1.2 g/kg is sensible, 1.2 to 1.6 during weight loss, and around 1.6 when building muscle with training. Older adults need more, not less, because ageing muscle responds less to the same dose. Spread it across meals rather than loading dinner, and start with breakfast, where almost everyone has room. And the kidney worry does not apply to healthy kidneys.
Frequently asked questions
How much protein do I need per day?
The minimum to prevent deficiency is about 0.8 g per kg of body weight, but many experts suggest 1.2-1.6 g/kg for muscle maintenance, active people, and older adults. The minimum isn't the optimum.
Does protein help with weight loss?
Yes. Protein is the most filling nutrient and helps preserve muscle during weight loss, which protects your metabolism. It's one of the most useful levers for eating less without feeling deprived.
What are the best sources of protein?
Lean meats, fish, eggs, dairy, beans and lentils, tofu, and Greek yogurt. Variety and protein quality matter, and spreading protein across meals helps your body use it.
