Setting a protein target takes about thirty seconds. Multiply a body weight by a number you already know, round it, type it into the client's profile.
Then the client eats 90g of it. Week after week, the check-in shows a protein average 40g under the figure you set, and every session you have about it is the same session. That gap — not the arithmetic — is the actual coaching problem, and most of the work in this article is about closing it rather than about picking a better number.
Set the calorie target first
Protein is a share of a calorie total, so the total has to exist first. Work out the client's calorie target, set protein, set a fat minimum, and let carbohydrate take what is left. If you need the underlying arithmetic and what each macro is doing, what macros are covers it.
The order matters because protein set in isolation produces a number the rest of the diet cannot accommodate. A client on 1,500 calories with a 190g protein target has 760 calories left for everything else, which is not a diet anyone follows for more than a fortnight.
Body weight or lean mass
Two ways to set the number, and the difference only matters for some clients.
Per kilogram of body weight is the default. It needs one figure you already have, it is what almost every published range is expressed in, and for a client anywhere near a normal body composition it lands in the same place as anything more sophisticated.
Per kilogram of lean mass removes fat from the calculation, which is theoretically tidier — fat tissue does not need feeding with protein. The problem is practical: you need a body fat figure, and unless you have a DEXA scan you have a caliper reading or a smart-scale estimate with an error range wide enough to swallow the entire benefit of the more precise method. Using a 5-point-wrong body fat figure to calculate a lean mass target is worse than using body weight.
Use lean mass when you have a genuine measurement. Otherwise use body weight, and use the adjustment below when body weight is the thing distorting the answer.
When body weight gives the wrong answer
For a client with a lot of fat to lose, body weight overstates the protein need badly. A 140kg client at 2.0 g/kg is a 280g target, which is not achievable, not necessary, and would crowd out every other food on the plan.
Three ways coaches handle it, in order of how much you need to know:
- Goal weight. Set the target against a realistic goal body weight rather than the current one. Simple, and it lands close enough.
- Adjusted body weight. Take the difference between current and goal weight, add a portion of it back — commonly a quarter to a half — and calculate from that. Slightly more generous than goal weight, which suits a client who is still carrying a lot of muscle underneath.
- Lean mass, if you actually have a measurement.
All three land in a similar place, and the difference between them is smaller than the difference between the target and what the client eats. Pick one and be consistent, because changing method mid-diet makes your own trend data unreadable.
Protein goes up in a deficit, not down
The instinct when cutting calories is to cut everything proportionally. Protein is the one that goes the other way.
Two reasons. In a deficit the body is looking for tissue to break down, and a higher protein intake is the main dietary lever for keeping that tissue from being muscle — training is the other. And protein is the most filling of the three macros per calorie, so a client on a low protein deficit is hungrier than a client eating the same calories with protein high.
The International Society of Sports Nutrition's 2017 position stand on protein and exercise puts 1.4–2.0 g/kg/day as sufficient for most exercising people, and notes that higher intakes of 2.3–3.1 g/kg/day may be needed to retain lean mass in resistance-trained people eating in a deficit. Worth knowing that the stand expresses that upper figure per kilogram of fat-free mass in places and per kilogram of body weight in others — for a lean client the two are close enough not to matter, and for a client with a lot of fat to lose they are not. Use lean mass or goal weight for that client, or 3.1 g/kg of body weight will hand you a number nobody is going to eat. That is the direction of travel: the harder the deficit and the more muscle there is to protect, the higher protein goes.
Coming out of a deficit, protein stays where it is and the extra calories go to carbohydrate and fat. When you are reversing a client out of a diet, protein is the one number you do not touch.
The ranges coaches work from
These are conventions, not findings. They are where the coaching field has settled, they are close enough to be useful, and the decimal-place precision usually attached to them is not supported by anything. A client eating 1.8 g/kg is not getting a measurably different result from one eating 2.0 g/kg.
| Client situation | Common range | Notes |
|---|---|---|
| General health, little or no resistance training | 1.2–1.6 g/kg | The floor, not a performance target |
| Training for muscle, calories at maintenance | 1.6–2.2 g/kg | Where most coaching clients sit |
| In a deficit, holding muscle | 2.0–2.4 g/kg | Higher end for leaner clients and harder deficits |
| Substantial fat to lose | 1.6–2.0 g/kg of goal weight | Calculate on goal or adjusted weight, not current |
| Older clients | Top of the relevant range | Protein needs rise with age, not fall |
Round to something a client can hold in their head. 165g is a target. 163.4g is a demonstration that you own a calculator.
Most clients land 30-50g short
This is the part nobody sets up for. A client who agrees to 170g will average something like 125g over their first month, and they will not know they are short until you show them.
Three reasons it happens, and each has a different fix:
They front-load carbohydrate and fat. Breakfast is toast, lunch is a sandwich, and by dinner there are 140g of protein left and no appetite. The fix is structural: put a protein source in every meal before anything else goes on the plate, and set a rough per-meal figure — 40g at each of three meals plus a 30g snack gets you to 150g without anyone doing arithmetic at the table.
They are logging inaccurately. Eyeballed portions run low on meat and high on everything else, and a client who has never weighed food is guessing at both. This is a teaching problem, not a compliance problem — teaching clients to track before you judge their numbers is the sequence that works.
The target was never realistic for their food. A client who does not eat meat, or eats one meal a day, or travels four days a week, needs a route to the number, not just the number.
In Fitsly you set protein on the client's profile in grams or as a percentage of the calorie goal, with date overrides for specific days, and it is the figure the client sees in the app when they log a meal. Seeing the gap while there is still a day left to fix it is what changes the weekly average.
Food first, supplements second
Protein powder is a convenience, not a strategy. A client who reaches their target on three shakes a day has not learnt anything they can keep doing, and their food will get worse in every other respect. Work through the food options first and let the shaker close the last 20 or 30 grams.
| Food | Serving | Approximate protein |
|---|---|---|
| Chicken breast, cooked | 150g | 45g |
| Lean beef mince, cooked | 150g | 40g |
| Salmon, cooked | 150g | 37g |
| Tinned tuna, drained | 95g tin | 22g |
| Prawns, cooked | 150g | 33g |
| Greek yoghurt | 200g | 20g |
| Cottage cheese | 100g | 12g |
| Eggs | 2 large | 12g |
| Milk | 250ml | 8g |
| Tempeh | 100g | 19g |
| Firm tofu | 150g | 18g |
| Cooked lentils | 1 cup | 18g |
| Cooked chickpeas | 1 cup | 15g |
| Protein powder | 30g scoop | 20–25g |
| Wholemeal bread | 2 slices | 8g |
Treat these as approximate. Cuts, brands and cooking method all move them, and Australian labels will disagree with an American database by a few grams. They are accurate enough to plan a day with, which is all a client needs.
Two habits do more than any individual food. Anchor each meal on a protein source and build the rest around it, rather than adding protein to a meal that is already designed. And keep two or three no-effort options in the house — tinned tuna, Greek yoghurt, eggs, a pouch of lentils — for the days that go wrong. If you are building a client a meal plan, those anchors are what the plan is really made of.
Vegetarian and vegan clients
The target does not change. The route to it is genuinely harder, and pretending otherwise sets the client up to fail.
Plant sources come packaged with carbohydrate or fat in a way animal sources do not. A cup of lentils is 18g of protein and around 40g of carbohydrate; 150g of chicken is 45g of protein and almost nothing else. So a vegan client hitting 160g of protein is spending far more of their calorie budget to get there, which matters most in a deficit where the budget is tight.
What works:
- Lean on the concentrated plant sources — tofu, tempeh, seitan, edamame, textured vegetable protein — rather than counting grams from bread and rice.
- Use a plant protein powder deliberately rather than apologetically. For a vegan client in a deficit it is often the only way the numbers close.
- Set the target at the lower end of the relevant band if the higher end forces a diet the client will not keep.
The last point is the one coaches get wrong. A 150g target hit consistently beats a 180g target missed by 45g every day, and the flexibility that makes a diet survivable is worth more than the extra 30 grams. Flexible dieting is the frame for that conversation.
Where your scope ends
Setting protein targets for a healthy adult is general nutrition guidance, which sits inside what a fitness coach does. Several things sit outside it, and the line is worth knowing before a client walks you across it.
The question you will get most is whether high protein damages the kidneys. The honest answer: in people with healthy kidneys, high protein intake has not been shown to cause harm. A 2018 systematic review and meta-analysis by Devries and colleagues in the Journal of Nutrition found that changes in kidney function did not differ between healthy adults eating higher-protein diets and those eating lower- or normal-protein diets. It is not evidence of harm, and it is also not a clearance you can hand to everybody.
Because for a client with known or suspected kidney disease, the situation is completely different. Protein intake is a clinical variable in kidney disease and it is managed by their doctor or a dietitian. You do not set a protein target for that client. You refer, you ask what intake they have been told to work within, and you build the rest of their nutrition around the number their clinician gives you.
The same applies to clients who are pregnant, have liver disease, have a history of disordered eating, or are on a prescribed diet for any condition. Refer out, get the boundaries in writing where you can, and coach inside them. This is not defensive paperwork — it is the part of the job that keeps you working.
