The Truth About Protein - How Much You Actually Need and Why Most People Get It Wrong
Protein is the most talked-about macronutrient in fitness culture. It is also the most misunderstood.
Half the people you know are obsessing over protein shakes and hitting arbitrary targets. The other half are eating nowhere near enough and wondering why they are always tired, losing muscle, and struggling to recover from exercise.
Here is what the science actually says — as of 2025 — and what it means for you specifically.
What Protein Actually Does
Protein is not just a muscle-building supplement. It is the structural material of your entire body.
Your muscles, skin, hair, nails, enzymes, hormones, antibodies, and the haemoglobin carrying oxygen in your blood — all protein. Every time a cell in your body dies and is replaced, protein is the raw material for the replacement. Every immune response requires protein. Every chemical reaction in your body is catalysed by enzymes made of protein.
You are not supplementing with protein. You are feeding the machinery that runs your body.
The Baseline — What You Actually Need
The Recommended Dietary Allowance (RDA) for protein is 0.8 grams per kilogram of body weight — but this represents the minimum amount to prevent deficiency in sedentary adults, not the optimal amount for health and performance. Harvard Health
This distinction matters enormously. The RDA is the floor, not the target.
For a 70kg sedentary adult, that baseline is 56 grams of protein per day. Most people eating a normal diet already hit this without thinking about it. This is not the number you need to obsess over.
What You Need If You Exercise
If you exercise regularly — even moderately — your protein needs increase significantly:
People who exercise regularly need approximately 1.1 to 1.5 grams of protein per kilogram of body weight. People who regularly lift weights or are training for an endurance event need 1.2 to 1.7 grams per kilogram. Mayo Clinic Health System
For muscle building specifically, the science has evolved. For most people lifting weights, a daily protein intake of 1.6 to 2.4 grams per kilogram of body weight is recommended to support muscle hypertrophy — with advanced athletes potentially benefiting from intakes at the higher end of this range. StrengthLab360
So for a 70kg person who trains regularly, that means roughly 112 to 168 grams of protein per day — roughly double the basic RDA.
The Old Rule About Protein Per Meal — Now Being Challenged
For years, the standard advice was that your body can only use 20 to 30 grams of protein per meal for muscle building, with anything beyond that being wasted.
A study published in Cell Reports Medicine challenged this, finding that eating 100 grams of protein in a single sitting led to a higher and more sustained spike in muscle protein synthesis compared to 25 grams — concluding that the anabolic response to protein ingestion has no apparent upper limit in magnitude. Hone Health
What this means practically: you do not need to panic about perfectly spacing out exactly 25g every 3 hours. Total daily protein intake matters most. Spreading it across meals is still sensible — but missing a protein window is not catastrophic.
What Happens When You Don't Eat Enough Protein
This is what chronic low protein intake looks like clinically:
- Persistent fatigue — protein is essential for energy metabolism and red blood cell production
- Muscle loss — your body will break down muscle tissue to access amino acids when dietary supply is insufficient
- Slow wound healing — collagen and tissue repair both require adequate protein
- Frequent illness — antibodies are proteins; low intake compromises immune function
- Hair thinning — hair is made of keratin, a protein
- Oedema — low albumin from protein deficiency causes fluid accumulation in tissues
- Brain fog — neurotransmitters including dopamine and serotonin are synthesised from amino acids
If several of these sound familiar — assess your protein intake before assuming something more complex is wrong.
Protein Myths — Addressed
"High protein damages your kidneys" In healthy people with normal kidney function, there is no evidence that high protein intake causes kidney damage. This concern applies specifically to people who already have diagnosed kidney disease, where protein restriction may be advised. If your kidneys are healthy, this is not a concern at normal dietary protein levels.
"You need protein shakes to hit your targets" You do not. Whole food protein sources are nutritionally superior because they come packaged with other nutrients. Protein shakes are a convenient supplement for people who struggle to hit targets through food — not a requirement.
In general, you should try to meet your dietary protein needs with whole foods rather than supplements, as manufactured foods do not contain everything you need from food, and manufacturers do not know everything that should be in food. Mayo Clinic Health System
"Plant protein is inferior" Plant proteins can absolutely meet your needs, but they require more planning. Most plant proteins are incomplete — meaning they are missing one or more essential amino acids. The solution is variety. Eating a wide range of plant protein sources across the day — legumes, grains, nuts, seeds, soy — provides all essential amino acids without any meat.
"More protein always equals more muscle" Exercise is what builds muscle. Protein provides the raw materials. Without progressive resistance training, extra protein alone does not build muscle — it simply gets used for energy or stored.
Best Protein Sources — Food First
Animal sources (complete proteins — contain all essential amino acids):
- Chicken breast — 31g protein per 100g
- Eggs — 13g per 2 eggs, arguably the most bioavailable protein source available
- Greek yoghurt — 10g per 100g, plus probiotics
- Salmon — 25g per 100g, plus omega-3 fatty acids
- Cottage cheese — 11g per 100g, slow-digesting, excellent before sleep
Plant sources (combine for complete amino acid profile):
- Lentils — 9g per 100g cooked, plus fibre and iron
- Chickpeas — 9g per 100g cooked
- Tofu — 8g per 100g
- Edamame — 11g per 100g
- Quinoa — 4g per 100g cooked, one of the few complete plant proteins
- Hemp seeds — 31g per 100g, excellent addition to smoothies or porridge
Practical Targets
| Who you are | Daily protein target |
|---|---|
| Sedentary adult | 0.8g per kg bodyweight |
| Moderately active | 1.2–1.5g per kg |
| Regular gym goer | 1.6–2.0g per kg |
| Building muscle actively | 2.0–2.4g per kg |
For a 70kg person training regularly, aim for 110–140g daily. Hit this consistently through food first, supplement only if needed.
The Final Word
Protein is not a trend. It is the structural foundation of your body. Most people who feel consistently low energy, struggle to recover from exercise, lose hair or get sick frequently are under-eating protein without realising it.
Hit your targets through real food, vary your sources, do not over-complicate it, and remember that no supplement replaces a consistent, varied diet.
This blog is for educational purposes and my personal opinion only and does not constitute medical or nutritional advice. Consult a registered dietitian for personalised nutritional guidance.
Written by Dr. Hari — follow on X @Harigaran21 for daily health and wealth insights.
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