Protein needs more space on your plate

In brief

The protein recommendation most adults learned is too low for preserving muscle past forty. Aim for 1.6 to 2.2 g per kg per day, spread across three meals of about 30 g each. Breakfast is the meal most people under-protein, and fixing it gives the biggest single uplift.

The protein recommendation most adults grew up with was set to prevent deficiency, not to support muscle, metabolism, or recovery. The current RDA of 0.8 g per kg of body weight per day was calibrated against nitrogen balance studies in young sedentary adults. The current evidence base, summarised by Stokes and colleagues in Nutrients (2018), puts the range needed for muscle preservation and growth at 1.6 to 2.2 g per kg per day, roughly two to three times what most adults consume.

Why spread matters as much as total

Muscle protein synthesis is triggered by leucine, an amino acid that needs a threshold dose at each meal to switch on the synthesis pathway. Roughly 30 g of high quality protein per meal hits this threshold. A breakfast of toast and tea, followed by a protein-heavy dinner, leaves twelve to sixteen hours of the day below the threshold. Three meals each containing 30 to 40 g of protein outperforms the same total eaten at one sitting, in both younger and older adults.

Most adults under-eat protein at breakfast and over-eat it at dinner. Evening it out is the highest-yield change.

What 30 g of protein actually looks like

Two large eggs plus a small cup of dahi or Greek yoghurt; three quarters of a cup of cooked lentils plus a small cup of paneer; 100 g of chicken or fish; a 30 g serving of whey isolate. Vegetarian sources lean on lentils, paneer, tofu, tempeh, and dairy. The threshold is harder to hit on plant protein alone because the leucine density is lower; raising the per-meal dose to 40 g compensates.

Key Takeaways

• •Aim for 1.6 to 2.2 g of protein per kg of body weight per day, not the older 0.8 g RDA.
• •Hit roughly 30 g of high quality protein at each of three meals, breakfast included.
• •Vegetarian sources need a slightly higher per-meal dose to clear the leucine threshold.