Protein Intake Calculator
Find your optimal daily protein target based on your body weight, activity level, age, and fitness goals. Results include a per-meal breakdown and food source guide.
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Spread your intake across 3–4 meals, aiming for —g per meal.
How much protein do you actually need?
The official RDA for protein is 0.8g per kg of body weight — but this represents the minimum to prevent deficiency in a sedentary adult, not an optimal intake. For anyone who exercises, wants to lose fat, or is over 50, the research consistently supports higher intakes.
Protein targets by goal
| Goal | Recommended intake | Why |
|---|---|---|
| General health | 1.0–1.2 g/kg | Maintains muscle, supports immunity |
| Fat loss | 1.8–2.4 g/kg | Preserves lean mass during calorie deficit |
| Muscle building | 1.6–2.2 g/kg | Maximises muscle protein synthesis |
| Endurance sports | 1.4–1.7 g/kg | Supports recovery and aerobic adaptation |
| Adults 50+ | 1.2–1.6 g/kg | Counters age-related muscle loss (sarcopenia) |
Why protein needs are higher during fat loss
When you're in a calorie deficit, your body can use muscle protein as an energy source through gluconeogenesis. Higher protein intake during fat loss (1.8–2.4g/kg) provides abundant amino acids, reducing the body's need to break down muscle tissue. Studies consistently show that high-protein diets during calorie restriction result in greater fat loss and better lean mass retention compared to lower-protein approaches at the same calorie intake.
Why older adults need more protein
Ageing reduces muscle sensitivity to protein — a process called anabolic resistance. Older muscles require a higher dose of protein per meal to trigger the same muscle protein synthesis response. Research suggests adults over 50 benefit from 30–40g of protein per meal to reliably stimulate muscle maintenance, compared to 20–25g for younger adults. The RDA of 0.8g/kg is particularly inadequate for this group.
📌 Protein and women's health
Women generally have lower absolute protein needs due to lower body mass, but the g/kg targets are the same. During perimenopause and menopause, oestrogen decline accelerates muscle loss — making adequate protein (1.2–1.6g/kg minimum) especially important. Women over 40 engaged in resistance training benefit most from the higher end of each range.
Spreading protein throughout the day
Total daily protein matters most, but distribution has a meaningful effect on muscle protein synthesis. Research shows spreading protein across 3–4 meals of 25–40g each is more effective than consuming the same total in one or two large meals. A protein-rich breakfast is particularly important — most people under-consume protein in the morning and overcorrect at dinner.
Protein quality: complete vs incomplete
Not all protein is equal. Complete proteins contain all nine essential amino acids in adequate proportions — these include all animal proteins, plus soy, quinoa, and buckwheat. Incomplete proteins are low in one or more essential amino acids. Plant-based eaters can get complete amino acid profiles by combining sources throughout the day (e.g. legumes with grains).
Leucine is the amino acid most responsible for triggering muscle protein synthesis. Animal proteins and soy are naturally high in leucine. Other plant proteins are lower, which is why plant-based eaters benefit from slightly higher total protein targets (10–20% more).
Best protein sources by category
| Food | Protein per 100g | Notes |
|---|---|---|
| Chicken breast (cooked) | 31g | Lean, high leucine |
| Canned tuna | 25g | Convenient, affordable |
| Salmon | 25g | High omega-3 |
| Eggs | 13g (2 eggs) | Complete protein, versatile |
| Greek yogurt | 10g | Also provides calcium |
| Cottage cheese | 11g | Slow-digesting casein |
| Tempeh | 19g | Best plant protein, fermented |
| Edamame | 11g | Complete plant protein |
| Lentils (cooked) | 9g | Also high in fibre |
| Whey protein | 24g/scoop | Fast-absorbing, high leucine |
Protein and the thermic effect of food
Protein has the highest thermic effect of any macronutrient — your body burns 20–30% of protein calories during digestion and metabolism, compared to 5–10% for carbohydrates and 0–3% for fats. This means a diet higher in protein naturally creates a small calorie deficit even without reducing portion sizes, contributing to its effectiveness for fat loss.
How protein affects hunger and satiety
Protein is the most satiating macronutrient. It reduces levels of the hunger hormone ghrelin and increases satiety hormones including GLP-1 and peptide YY. In practical terms, high-protein meals keep you full longer and reduce total calorie intake at subsequent meals — a significant benefit for anyone managing their weight.