Why does protein matter?
Protein is your body's building block: the core component of muscle, bone, skin, hair, enzymes, and hormones. Unlike carbohydrate and fat, the body can't store much protein, so you need to get it regularly. Enough protein preserves and builds muscle mass, keeps you fuller for longer (an advantage in weight management), and supports immunity and recovery. When you're losing weight in particular, enough protein ensures you lose fat instead of muscle.
How are protein needs calculated?
Unlike daily calories, protein needs are calculated directly from your body weight. The grams-per-kilogram (g/kg) coefficient varies by goal:
General health ..... 0.8–1.0 g/kg
Active person ...... 1.2–1.6 g/kg
Weight loss ........ 1.6–2.0 g/kg
Muscle building .... 1.6–2.2 g/kg
Athlete / intense .. 1.8–2.4 g/kg
Example: For someone weighing 75 kg with a muscle-building goal:
Lower: 75 × 1.6 = 120 g · Upper: 75 × 2.2 = 165 g → about 120–165 g of protein a day. Split across 4 meals, that's ~35 g per meal.
Method: The g/kg ranges per body weight are based on sports nutrition position stands: the International Society of Sports Nutrition (ISSN — Jäger et al., 2017: 1.4–2.0 g/kg for muscle) and the joint statement from ACSM and the Academy of Nutrition and Dietetics.
Good protein sources
Combine a variety of quality sources to hit your goal:
- Animal: chicken breast, turkey, eggs, fish, beef, yogurt, cottage cheese, milk.
- Plant: lentils, chickpeas, beans, tofu, edamame, quinoa, almonds, chia.
- Handy: egg (~6 g each), 100 g chicken (~30 g), 1 scoop whey (~24 g), 200 g yogurt (~10 g).
Frequently asked questions
In a calorie deficit, the body tends to burn muscle alongside fat for energy. Enough protein (1.6–2.0 g/kg) and resistance training ensure most of the loss comes from fat; protein is also the most filling nutrient, which makes sticking to the deficit easier.
The '30 g per meal limit' is a myth; the body digests and uses more than that. Still, to maximize muscle protein synthesis, spreading protein across the day and taking ~25–40 g per meal is a practical and effective strategy.
No. Whey and plant-based powders are just a convenient source; you can meet your goal with real food too. If you train intensely or struggle to hit your daily target, powder offers convenience, but it's not required.
Yes. By combining legumes, tofu, tempeh, edamame, quinoa, nuts, and whole grains, you can get all the amino acids you need (the building blocks of protein). Since plant proteins are a little less digestible, setting your target slightly higher (e.g. +10%) can help.
In people with healthy kidneys, there's no strong evidence that a high-protein diet harms the kidneys; this is a common misconception. The 'kidney damage' warning applies to people who <b>already have kidney disease</b> — they may need to restrict protein. For a healthy adult, the 1.6–2.2 g/kg range is considered safe. Even so, it's wise to increase your water intake as you raise your protein, and to always consult a doctor if you have kidney or liver disease.
No, it's not a must — protein powder is just a <b>practical convenience</b>, not a magic food. You can meet all of your needs from real foods like eggs, meat, fish, dairy, and legumes. Powder helps when your appetite is low, your target is high (an athlete), or it's hard to reach enough protein with solid food on busy days. First work out how much you're getting from real food; if you fall short, powder is a handy tool to close that gap.