How much protein do you need to lose fat and keep muscle?
Most people losing fat in South Africa should aim for roughly 1.6–2.4 g of protein per kg of body weight a day, which is 128–192 g for an 80 kg adult. Lean, well-trained people in a steep deficit sit at the top of that range. Protein protects muscle and fullness, but only a calorie deficit plus resistance training changes your body composition.
- ISSN: 1.4–2.0 g/kg/day for most exercising adults; 2.3–3.1 g/kg/day may help preserve lean mass in trained people in a deficit.
- Morton 2018 (49 trials): protein supplementation added about 0.30 kg fat-free mass; benefits plateaued near 1.6 g/kg/day.
- Per meal: about 0.4 g/kg across at least four meals, roughly 32 g for an 80 kg adult (Schoenfeld and Aragon, 2018).
- Primal Whey Isolate 750 g costs R700 at Dis-Chem Living Fit, about R93 per 100 g of powder (October 2026).
What is the right protein target when you are dieting?
When energy intake drops, the body needs more protein to hold on to muscle. For most exercising adults the International Society of Sports Nutrition (ISSN) recommends 1.4–2.0 g/kg/day; in a calorie deficit, targets move higher, and the ISSN notes that 2.3–3.1 g/kg/day may help preserve lean mass in trained people who are cutting. A meta-analysis of 49 trials by Morton and colleagues (2018) found muscle benefits levelled off at about 1.6 g/kg/day on average, although the confidence interval stretched to 2.2 g/kg.
A practical working range for South African gym-goers and recreational athletes is therefore:
| Situation | Protein target | Example for an 80 kg adult |
|---|---|---|
| Moderate deficit, lifting 2–3 times a week | 1.6–2.0 g/kg | 128–160 g a day |
| Bigger deficit, lean, or training hard | 2.0–2.4 g/kg | 160–192 g a day |
| Very lean, advanced lifter under coaching | up to 2.3–3.1 g/kg (ISSN) | needs a sports dietitian |
If you carry a lot of body fat, work from a goal body weight rather than your current weight, otherwise the number gets unrealistically large.
How should you spread it across the day?
Aim for about 0.4 g/kg per meal over at least four meals (Schoenfeld and Aragon, 2018). For an 80 kg person that is about 32 g at breakfast, lunch, supper and a snack. Some examples of roughly 25–30 g of protein: 100 g cooked chicken breast, 3 large eggs plus a yoghurt, or 70 g of biltong.
Do you need a powder?
No. Powder is a convenience tool for people who struggle to reach the target from food, and it adds few calories per gram of protein. As of October 2026, whey isolate costs from about R93 per 100 g of powder (Primal Whey Isolate 750 g at R700, Dis-Chem Living Fit) to R112–R119 for ATP Fitness isolate (800 g at R900–R950 on shop.atpfit.co.za). USN Isozero (805 g, R899–R909.99 on the USN shop) states 20 g of protein per 23 g scoop. Isolate suits people cutting because it has less lactose, fat and carbohydrate per scoop than concentrate, but muscle outcomes per gram of protein are about the same. See isolate vs concentrate and our best whey isolate comparison.
ATP's isolates are sweetener-free and single-ingredient, which some people prefer. The trade-offs: the shop does not publish protein per serving, the price per 100 g is higher than Primal's, and no third-party sport certification is published. Compare labels before you buy.
What else makes protein work for fat loss?
- Resistance training two to four times a week is the signal that tells the body to keep muscle. Protein without training protects far less.
- A modest deficit of roughly 300–500 kcal a day loses fat with less muscle loss than crash dieting.
- Total daily intake matters more than timing. Shakes straight after training are convenient, not essential.
Who should be careful?
If you have chronic kidney disease, speak to your doctor or a renal dietitian before raising protein. Healthy kidneys are not harmed by these intakes in the research we reviewed. Under-18s, pregnant women and anyone with a history of disordered eating should get individual advice from a registered dietitian rather than following a number from a web page.
For a fuller guide see how much protein per day and what to take during a cutting phase.
Products mentioned, with dated prices
| Product | Size | Price | R per 100 g powder | R per 30 g protein | Sweeteners |
|---|---|---|---|---|---|
| Primal Whey Isolate (750 g) | 750 g | R700Dis-Chem Living Fit, Oct 2026 | R93.33 | — | sucralose |
| USN Isozero Whey Protein Isolate (805 g) | 805 g | R899-R909.99USN shop (za.usn.global), Oct 2026 | R111.68 | R38.53 | not stated |
| ATP Fitness Madagascan Vanilla Whey Protein Isolate | 800 g | R950ATP Fitness shop, Oct 2026 | R118.75 | — | None |
ATP Fitness is a commercial partner of Healthnews24 and its products are featured on this site. Rankings follow our published method, and every pick, including ATP Fitness, shows its price maths and trade-offs. Read our disclosure.
Related questions
- How much protein do I need per day in South Africa?
- Do protein shakes help you lose weight?
- Which supplements help during a cutting phase in South Africa?
- How much protein do you need to build muscle?
- What is the best protein powder for weight loss in South Africa?
Sources
- Jäger R et al. (2017) ISSN position stand: protein and exercise. JISSN
- Morton RW et al. (2018) Protein supplementation and resistance-training-induced gains: systematic review, meta-analysis and meta-regression. BJSM
- Schoenfeld BJ & Aragon AA (2018) How much protein can the body use in a single meal for muscle-building? JISSN
Educational information only, not medical advice. Speak to a doctor, pharmacist or registered dietitian before using supplements if you are pregnant or breastfeeding, under 18, taking medication, or living with kidney, liver or heart disease.
Cite this page: Healthnews24, “How much protein do you need to lose fat and keep muscle?”, updated 27 October 2026, https://www.healthnews24.co.za/answers/how-much-protein-to-lose-fat/. Plain-text version: /answers/how-much-protein-to-lose-fat.md