Most adults who train with weights need roughly 1.6 to 2.2 grams of protein per kilogram of body weight per day, which is 128g to 176g for someone weighing 80kg. The Australian recommended dietary intake for a sedentary adult is much lower, at 0.84g per kilogram for men and 0.75g for women. Mr PT Fitness is a private home studio in Dee Why run by Matt Reilly, a personal trainer with 10+ years' experience. Protein is the one nutrient where most people we see at the studio are genuinely short, and it is usually the first thing worth fixing.
How much protein per day do you need?
Work from your body weight, not from a fixed number of grams. Multiply your weight in kilograms by 1.6 to 2.2 if you train with weights, or by 0.75 to 0.84 if you are largely sedentary. That single calculation covers most healthy adults and removes the guesswork.
The reason those two ranges sit so far apart is that they answer different questions. The Australian recommended dietary intake is the amount that prevents deficiency in the general population. It is a floor, not a target. The higher range comes from research on people lifting weights, where the goal is building or keeping muscle rather than simply avoiding a shortfall.
A worked example. An 80kg office worker from Collaroy who walks the dog and does nothing else needs about 67g a day to meet the recommended intake. The same person training three times a week at the Dee Why studio is better served by 128g to 160g. That is roughly double, and it is why "I eat plenty of protein" and "I eat enough protein for what I am asking my body to do" are two different statements.
What is the simple per-kilogram guideline?
Pick the row below that matches your situation, multiply by your body weight in kilograms, and treat the result as a daily target you hit most days rather than a number you chase precisely. Consistency across a week matters more than accuracy on any single day.
| Situation | Daily target | Example at 80kg |
|---|---|---|
| Sedentary adult (Australian recommended intake) | 0.75 to 0.84g per kg | 60g to 67g |
| Generally active, not training for muscle | 1.2 to 1.6g per kg | 96g to 128g |
| Training with weights, building or keeping muscle | 1.6 to 2.0g per kg | 128g to 160g |
| Eating in a deficit for fat loss | 1.8 to 2.2g per kg | 144g to 176g |
| Over 50 and holding on to muscle | 1.2 to 1.6g per kg | 96g to 128g |
Two adjustments are worth knowing. If you are carrying a lot of body fat, calculating from your goal weight rather than your current weight gives a more sensible target, because fat tissue does not need feeding with protein. And older adults generally need more per meal than younger adults to get the same muscle-building response, which is why the over-50s range sits above the sedentary one even for people who are not lifting heavy.
Why does protein matter most in a fat-loss phase?
In a calorie deficit, protein is what protects your muscle while body fat comes off, and it is the most filling of the three macronutrients, so it makes the deficit easier to hold. Lose weight on low protein and a meaningful share of what you lose can be muscle rather than fat.
It also costs the most energy to digest. Roughly 20 to 30% of the calories in protein are used up processing it, against 5 to 10% for carbohydrate and almost nothing for fat. That is a small effect on its own, but it runs in your favour every day. The bigger win is appetite: a meal built around protein tends to keep you full for longer, which quietly reduces the snacking that undoes most diets. The maths behind all of this is covered in energy balance explained.
This is also why protein is the habit we start with rather than calorie counting. It is one rule, it applies to every meal, and it works whether or not you ever open a tracking app.
Not sure what your number should be?
Free 15-minute consult at the Dee Why studio. We will work out your protein target from your weight and training, then look at what your week actually looks like. Book here or call 0422 745 334.
How do you hit the protein target with real food?
Anchor every meal with a palm-sized serve of a protein food, roughly 25 to 40g, three or four times a day. Four meals at 35g gets an 80kg trainee to 140g without a single shake or a spreadsheet.
| Food | Typical serve | Protein |
|---|---|---|
| Chicken breast, cooked | 100g | about 30g |
| Lean beef mince, cooked | 100g | about 26g |
| Salmon, cooked | 100g | about 25g |
| Tinned tuna, drained | 95g tin | about 23g |
| Greek yoghurt | 200g tub | about 19g |
| Lentils or chickpeas, cooked | 1 cup | about 18g |
| Firm tofu | 150g | about 17g |
| Eggs | 2 large | about 12g |
| Milk | 250ml | about 8g |
Breakfast is where the shortfall usually starts. Toast, cereal and fruit together might total 10g, which leaves a large gap to close by dinner. Adding eggs, Greek yoghurt or milk to the morning is the single change that moves most people's daily total the furthest.
Cost is a fair concern. Eggs, tinned tuna, milk, Greek yoghurt, chicken thigh, mince and dried legumes all deliver protein cheaply, so a higher intake does not have to mean a bigger shop. If you eat little or no meat, build meals around dairy, eggs, tofu, tempeh and legumes, and expect to eat a slightly larger volume of food to reach the same number.
What are the signs you are under-eating protein?
The common pattern is feeling hungry again an hour after meals, grazing through the evening, and strength that sits flat for months despite turning up to sessions. These are everyday signs worth acting on, not a diagnosis of anything.
- Hungry soon after eating: meals built mostly on carbohydrate and fat tend to empty the tank faster
- Night snacking: often the body catching up on a day that started at 10g of protein
- Strength stalling: training hard but not adding weight to the bar over a training block
- Weight down, shape unchanged: losing scale weight while looking softer can point to muscle going with the fat
- Recovery dragging: feeling flat and sore for longer than a session warrants
Any of these can also have causes that have nothing to do with protein, including sleep, stress, training design and medical conditions. If you have persistent fatigue, unexplained weight change, a diagnosed condition, or you are pregnant, see your GP or an Accredited Practising Dietitian rather than adjusting your diet on your own. A personal trainer can give general nutrition guidance, and individual dietary treatment sits with them.
If you want a plan rather than a rule of thumb, the personal trainer nutrition plan explains what a general plan within PT scope covers, and how it sits alongside 1-on-1 sessions from $50 listed under services. Plenty of clients from Dee Why, Brookvale and Curl Curl start with nothing more complicated than protein at every meal.
General information, not individual medical or dietary advice. See your GP or an Accredited Practising Dietitian (APD) for your situation.
Frequently asked questions
How many grams of protein a day do I need?
Multiply your body weight in kilograms by 1.6 to 2.2 if you train with weights, and by 0.75 to 0.84 if you are sedentary. An 80kg person who trains lands somewhere between 128g and 176g a day. Spread it across three or four meals of 25 to 40g rather than trying to fit it all into dinner.
Can you eat too much protein?
For healthy adults, the intakes used in training research, up to roughly 2.2g per kilogram, are generally well tolerated. The practical limit is that very high protein crowds out carbohydrate, fat and fibre you also need. If you have kidney disease or any other medical condition, speak to your GP or an Accredited Practising Dietitian before raising your intake.
Do I need protein powder?
No. Protein powder is a convenience food, not a requirement. It is simply a fast, portable way to add roughly 20 to 25g when a real meal is not practical, such as straight after an early session. If you already hit your target with chicken, fish, eggs, dairy and legumes, powder adds nothing you are missing.
Start with protein, then build the rest
Free 15-minute consult at the Dee Why studio. We will set your protein target, sort out breakfast, and put training around it that fits your week on the Northern Beaches.