Protein Intake Calculator

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

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.

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

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.

Protein intake for specific populations

Protein for women

The g/kg protein targets are the same for women as men. However, because women typically have lower total body mass, absolute daily targets are lower. Women undergoing perimenopause and menopause face accelerated muscle loss as oestrogen declines — making protein intake (1.2–1.6g/kg minimum, ideally 1.8g/kg) particularly important during this life stage. Research from McMaster University shows that women doing resistance training with high protein intake can largely offset age-related muscle loss.

Protein for endurance athletes

Endurance athletes (runners, cyclists, triathletes) have traditionally been told protein matters less than for strength athletes. This is outdated. Endurance training causes significant muscle protein breakdown, and recovery depends on adequate protein synthesis. A 2011 review in the International Journal of Sport Nutrition supports 1.4–1.7g/kg for endurance athletes — above the general population but below the muscle-building range.

Protein while losing fat

The case for high protein during a calorie deficit is stronger than for any other situation. A landmark 2016 study by Antonio et al. found that subjects consuming 3.4g/kg of protein while resistance training and in a calorie deficit gained muscle and lost fat simultaneously — a recomposition outcome. While most people don't need to go this high, the finding confirms that erring on the higher end of protein intake during fat loss is beneficial, not excessive.

How to actually hit your protein target

Knowing your target is one thing. Consistently hitting it is another. These approaches work:

• Anchor every meal with a protein source first. Plan the protein component before deciding on carbs and fat. This prevents the common pattern of filling up on other food and having no room for protein.
• Eat protein at breakfast. Most people naturally underconsume protein in the morning. Eggs, Greek yogurt, cottage cheese, or a protein shake shifts your daily distribution toward the optimal 3–4 meals of 25–40g.
• Batch cook protein sources. Having pre-cooked chicken, hard-boiled eggs, or cooked lentils ready in the fridge removes the friction that causes people to reach for lower-protein options.
• Use protein powder as a gap-filler, not a primary source. When whole food intake falls short — after a long workout, during travel, or on high-volume training days — a protein shake fills the gap efficiently.
• Track for 2–3 weeks. Most people are surprised by how far from their target they actually are. Short-term tracking builds an accurate mental model that makes eyeballing more reliable long-term.