If you are active and want to keep your muscle, aim for somewhere around 1.6 g of protein per kg of bodyweight per day. After 50, treat 1.2 g/kg as your floor, not your goal. And the famous 0.8 g/kg figure you have seen quoted as "the recommended amount" is not a target at all. It is the minimum that stops you from going into deficiency. Those are two very different jobs, and confusing them is the single biggest protein mistake we see.
The good news: you do not need an app, a scale, or a spreadsheet to get this roughly right. You need your bodyweight and one sensible multiplier. The rest of this is just explaining why, and where the real evidence stops and the gym-bro folklore begins.
The RDA is a deficiency floor, not your optimum
The 0.8 g/kg/day number is the Recommended Dietary Allowance for protein, and it has barely moved in over 70 years. Here is the part nobody mentions: the RDA is defined as the amount judged adequate to meet the needs of nearly all healthy people, and for protein it was specifically derived to estimate the minimum needed to avoid losing body nitrogen. In plain terms, it is the level that keeps a sedentary adult from slowly wasting away.
Harvard Health puts it bluntly: the RDA is "the minimum amount you need to keep from getting sick, not the specific amount you are supposed to eat every day". Reading "minimum to prevent deficiency" as "ideal for staying strong" is like treating the legal minimum tyre tread as the recommended tread. It is the point below which things go wrong, not the point you are aiming for.
For a sedentary 70 kg adult who never lifts anything heavier than a shopping bag, 0.8 g/kg (about 56 g/day) is genuinely fine. The trouble is that almost nobody reading this is that person, and almost nobody wants to merely avoid deficiency. You want to keep the muscle you have, ideally for decades.
What the evidence actually says: around 1.6 g/kg
The most-cited number in this space comes from a 2018 systematic review and meta-analysis in the British Journal of Sports Medicine by Morton and colleagues. It pooled 49 randomised controlled trials and 1,863 participants, which is a genuinely large evidence base, not one flashy study.
The headline finding: protein intake above roughly 1.62 g/kg/day produced no further gains in fat-free mass during resistance training. That is the point of diminishing returns, where extra protein stops adding measurable muscle. The confidence interval ran from about 1.03 up to 2.20 g/kg/day, so there is real uncertainty around the exact breakpoint, and some people may benefit from a touch more. But the centre of gravity sits at roughly double the RDA, not at the RDA.
Two honest caveats from the same paper. First, this was about protein paired with resistance training: protein on its own without lifting is not a muscle strategy. Second, the muscle-building effect was reduced with increasing age, which is exactly why older adults need to be more deliberate, not less. More on that next.
After 50, the floor rises
This is the part that matters most if you are reading this in your 40s and thinking about the decades ahead. Muscle is the healthspan tissue. It is what keeps you carrying luggage upstairs, getting off the floor unassisted, and staying out of a care setting later. After 40, you lose it faster unless you actively defend it, and protein plus strength work is how you do that.
Singapore's HealthHub guidance for older adults is refreshingly clear here: adults aged 50 and above need about 1.2 g/kg/day, roughly 50% more than the 0.8 g/kg quoted for younger adults, to better preserve muscle mass and strength. And the gap is real on the ground. HealthHub notes that one in two older adults in Singapore do not meet their protein needs for their age. So if anything, the local risk is eating too little, not too much.
Worth flagging: 1.2 g/kg is the older-adult floor, the don't-go-below line. If you are over 50 and training, the active-adult target of around 1.6 g/kg is the more useful number to aim at, because the muscle-protecting job gets harder with age, not easier. If you are coming off a GLP-1 medication or thinking about one, getting enough protein matters even more, because rapid weight loss strips muscle along with fat.
The "30 g window" panic is mostly folklore
Here is a myth worth burying: the idea that your body can only use about 30 g of protein per meal, so anything above that is wasted. It made everyone anxious about hitting a magic post-workout number within some narrow window.
The 2018 review by Schoenfeld and Aragon in the Journal of the International Society of Sports Nutrition takes this apart. The old "20 to 25 g maxes out muscle protein synthesis" finding came from studies using fast-digesting protein in isolation. Eat protein as part of a normal meal, with fats and carbs slowing things down, and your body keeps using more of it. Their practical recommendation: aim for roughly 0.4 g/kg per meal across at least four meals to comfortably reach a minimum of 1.6 g/kg/day.
Notice what is doing the work there. The lever is the daily total, with the per-meal split as a sensible way to reach it, not a fragile timing trick you can fail. You do not need to inhale a shake within 30 minutes of your last rep. You need to hit a reasonable amount across the day, spread over a few meals. Singapore's HealthHub echoes this for older adults, suggesting roughly 25 g of protein at each of the three main meals so muscle-building is stimulated throughout the day rather than crammed into one sitting.
A simple way to estimate your own target
No app required. Take your bodyweight in kg and pick a multiplier based on where you are:
- Sedentary, just avoiding deficiency: about 0.8 g/kg. This is the floor, not a goal.
- Active and wanting to protect or build muscle: around 1.6 g/kg.
- Aged 50 and above: treat 1.2 g/kg as your minimum, and aim toward 1.6 g/kg if you are training.
So a 70 kg active adult lands near 112 g/day. Split across four meals, that is roughly 28 g each, which is one palm-sized portion of chicken, fish, tofu, eggs, or dairy per meal. A 60 kg person aiming at 1.6 g/kg is near 96 g/day, about 24 g per meal across four. These are estimates to anchor on, not prescriptions, and they assume normal kidney function and no medical condition that changes the picture.
If hitting that feels hard, the fix is usually structural rather than supplemental. Front-load it: a protein-forward breakfast closes most of the gap before lunch, because the typical local breakfast (kaya toast, a bun, plain noodles) is where protein quietly goes missing. Eating out is no excuse either, given how much protein a Singapore hawker centre can deliver if you order with intent. And if you genuinely cannot get there from food, a scoop of whey is a convenience tool, not a magic one. We have a rundown of protein powders worth buying in Singapore if that is the route, but treat it as topping up a mostly-food diet.
When more protein is not the answer
A few honest limits, because more is not always better. Above roughly 1.6 g/kg paired with training, the muscle-building returns flatten out, per Morton's data. Pushing far higher will not hurt a healthy person, but it mostly just gets oxidised for energy, so do not expect extra grams to buy extra muscle on their own.
Protein also cannot substitute for the training stimulus. Every bit of the strongest evidence here is about protein plus resistance work. Eat all the chicken you like; without the lifting, you are mostly feeding maintenance, not growth.
And there is a group that needs a clinician in the loop. If you have chronic kidney disease or any condition affecting protein metabolism, the standard advice does not apply to you, and high intakes can be genuinely risky. This is general information, not medical advice. See a clinician before significantly raising your protein intake if you have kidney disease, are pregnant, or manage any chronic condition.
For most active adults in their 40s and beyond, though, the message is simpler than the internet makes it sound. Eat enough protein, spread it across the day, and lift something heavy a few times a week. The number to remember is around 1.6, not 0.8.
How much protein do I need per day?
Active adults aiming to keep muscle often land around 1.6 g per kg bodyweight daily. After 50, treat 1.2 g per kg as a floor, not a target.
Is 0.8 g per kg enough?
That figure is the deficiency floor for sedentary adults, not an optimum for training or ageing muscle.
Do I need protein shakes?
Only if food falls short of your daily target. Whole food works fine when you hit grams consistently.
Can you eat too much protein?
Healthy kidneys generally tolerate high protein in research on active adults. People with kidney disease need clinician guidance.
How should I split protein across the day?
Roughly 20 to 40 g per meal across three to four eating occasions is a practical split for most people.
FAQ
How much protein do I need per day?
Active adults aiming to keep muscle often land around 1.6 g per kg bodyweight daily. After 50, treat 1.2 g per kg as a floor, not a target.
Is 0.8 g per kg enough?
That figure is the deficiency floor for sedentary adults, not an optimum for training or ageing muscle.
Do I need protein shakes?
Only if food falls short of your daily target. Whole food works fine when you hit grams consistently.
Can you eat too much protein?
Healthy kidneys generally tolerate high protein in research on active adults. People with kidney disease need clinician guidance.
How should I split protein across the day?
Roughly 20 to 40 g per meal across three to four eating occasions is a practical split for most people.
Sources
- Morton RW, et al. A systematic review, meta-analysis and meta-regression of the effect of protein supplementation on resistance training-induced gains in muscle mass and strength in healthy adults. British Journal of Sports Medicine, 2018.
- Schoenfeld BJ, Aragon AA. How much protein can the body use in a single meal for muscle-building? Implications for daily protein distribution. Journal of the International Society of Sports Nutrition, 2018.
- Institute of Medicine. Protein and Amino Acids (Recommended Dietary Allowances). National Academies Press / NCBI Bookshelf.
- Harvard Health Publishing. How much protein do you need every day?
- HealthHub Singapore (Health Promotion Board). Older Adults Need More Protein.
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