Protein
A macronutrient made of amino acids, essential for building and repairing tissues (muscles, organs, skin) and for making enzymes, hormones and antibodies.
Protein is the body’s « building blocks »: muscles, skin, hair, nails, enzymes, hormones and antibodies are all made of protein. It is made from 20 amino acids, 9 of them essential (which must come from food).
The original angle (the most filling and « costly » macronutrient): of the three macronutrients, protein has unique properties:
- The most filling: it suppresses ghrelin (hunger) and stimulates satiety hormones. A high-protein breakfast reduces hunger all day
- The most « costly » to digest: ~25% of its calories are burned just in digestion (the thermic effect), against ~8% for carbohydrate and ~2% for fat
- A « muscle-sparing » effect: in a calorie deficit, enough protein preserves muscle (you lose fat, not muscle)
These three properties make protein the number one ally for weight management and body composition.
How much do you need? (with nuance)
- Sedentary: ~0.8-1 g/kg/day (minimum)
- Active/sporty: 1.4-2 g/kg/day
- Weight loss (preserving muscle): ~1.6-2 g/kg
- Older adults: higher (~1-1.2 g/kg) because of anabolic resistance
Myth-busting:
- Excess protein does not « damage the kidneys » in healthy people (a stubborn myth); only people with kidney failure need to limit it
- The « complete/incomplete protein » debate is nuanced: combined plant foods meet your needs (see amino acids)
- Spreading it across meals (~20-40 g each) is better than concentrating it all in one meal
Sources: animal (meat, fish, eggs, dairy, with a complete profile) and plant (pulses, tofu, seitan, cereals, to be combined). A varied plate easily covers your needs.