Protein requirements are among the most individualised aspects of nutrition. The standard recommendation of 0.8 grams per kilogram of body weight was established to prevent deficiency in sedentary populations, not to optimise body composition, performance, or longevity. For anyone with goals beyond simply not being deficient, protein needs are substantially higher and should be calculated from lean body mass rather than total body weight.
Evidence-Based Recommendations by Goal
For fat loss, protein requirements increase to 1.6 to 2.2g per kilogram of lean body mass. Higher protein intake during caloric deficit preserves muscle mass, supports satiety, and increases the thermic effect of food. For muscle gain, similar ranges apply: 1.6 to 2.2g per kilogram of lean body mass, with the emphasis on distributing intake across meals to maximise muscle protein synthesis. For maintenance, 1.2 to 1.6g per kilogram of lean body mass is typically sufficient for active individuals. For longevity, emerging research supports moderate to high protein intake of 1.2 to 1.6g per kilogram of lean body mass, with emphasis on leucine-rich sources that combat age-related muscle loss.
The key insight is that lean body mass, not total body weight, is the appropriate denominator. A 100kg person with 30% body fat has 70kg of lean mass; their protein target should be based on 70kg, not 100kg. This is one reason body composition scanning is essential for personalised nutrition programming.
Age-Specific Considerations
Protein requirements change across the lifespan due to a phenomenon called anabolic resistance. After approximately age 40, the muscle protein synthesis response to a given protein dose diminishes, meaning older adults need more protein per meal to achieve the same anabolic stimulus as younger adults. Practical implications include a higher per-meal protein threshold of 30 to 40g for adults over 40, greater importance of leucine-rich protein sources, increased total daily protein to offset reduced efficiency, and greater value from resistance training combined with protein timing.
Protein Quality and Bioavailability
Not all protein sources are equal. The Digestible Indispensable Amino Acid Score (DIAAS) measures protein quality based on amino acid profile and digestibility. Highest quality sources include whey protein, eggs, dairy, poultry, and fish. Moderate quality includes beef, pork, and soy. Lower quality includes most plant proteins (legumes, grains, nuts), which can be combined to achieve complete amino acid profiles.
For clients with high protein targets and limited appetite, choosing high-bioavailability sources means less total food volume is needed to meet targets.
Timing and Distribution
Research on the leucine threshold suggests that muscle protein synthesis is maximally stimulated when each meal contains at least 2.5 to 3g of leucine (roughly 25 to 40g of complete protein, depending on the source). Consuming protein in 3 to 5 distributed meals throughout the day provides more total muscle protein synthesis stimulation than consuming the same amount in 1 to 2 meals. Pre-sleep protein, particularly casein, may support overnight muscle protein synthesis.
Practical Sources for New Zealanders
New Zealand has excellent access to high-quality protein. Lamb and beef from grass-fed New Zealand stock provide complete protein with beneficial fatty acid profiles. Wild-caught fish including hoki, blue cod, and salmon are readily available. Free-range eggs are widely accessible. Dairy including Greek yoghurt, cottage cheese, and whey protein supplements round out the options. For plant-based clients, tofu, tempeh, legumes, and strategic combinations can meet targets with more planning.
Frequently Asked Questions
Can I eat too much protein? For healthy individuals with normal kidney function, protein intakes up to 2.2g per kg of lean mass are well tolerated. The outdated concern about protein damaging kidneys has been consistently refuted in research on healthy populations.
Is collagen protein as good as whey? They serve different purposes. Collagen provides specific amino acids (glycine, proline, hydroxyproline) important for connective tissue but lacks the leucine content to maximally stimulate muscle protein synthesis. Whey is superior for muscle building. Both have value in a complete programme.
Do I need protein powder? Not necessarily. Powder is a convenience tool. If you can meet your protein targets through whole foods, supplements are optional. For many clients with high targets and limited appetite, protein supplements become practically necessary.
Your protein needs are personalised to your data, not a generic calculator. Get started with coaching and learn about muscle preservation during weight loss.
