Protein is essential for muscle maintenance, immune function, hormone production and tissue repair. The confusion comes from extremes. Some argue most people are deficient. Others warn that high protein accelerates ageing. The truth is contextual. Requirements depend on age, activity level and metabolic health.
The Minimum Is Not the Target
The current Recommended Dietary Allowance (RDA) is 0.8 g per kilogram of body weight per day¹. For a 70 kg adult, that equals 56 grams daily. But the RDA is designed to prevent deficiency in sedentary individuals. It is not an optimal intake for muscle preservation or metabolic resilience. It is the minimum required to avoid deficiency, not the amount that supports healthy ageing.

Ageing Changes the Equation
After the age of 30, skeletal muscle gradually declines - a process known as sarcopenia². With ageing, muscles become less responsive to protein intake, a phenomenon called anabolic resistance³. For this reason, many experts suggest 1.0–1.2 g/kg/day for healthy older adults³. That same 70 kg adult may benefit from 70–85 grams daily. Longevity requires preserving muscle. Muscle requires sufficient protein.
Muscle Is Metabolic Infrastructure
Skeletal muscle is the largest site of insulin-mediated glucose disposal⁴. Lower muscle mass is associated with increased insulin resistance and metabolic instability⁵. Protein supports muscle maintenance. Resistance training amplifies its effect. This is not aesthetic. It is metabolic regulation.
Protein and Satiety
Protein increases satiety more than carbohydrate or fat⁶. It stimulates GLP-1 and peptide YY, hormones involved in appetite regulation⁶. Adequate protein can stabilise appetite across the day. However, protein does not replace fibre, sleep or meal structure. It is one part of appetite regulation, not the entire system.
So What Is a Practical Target?
For most adults:
0.8 g/kg/day = minimum¹
1.0–1.2 g/kg/day = supportive for healthy ageing³
1.2–1.6 g/kg/day = appropriate for resistance training or high activity⁷
For a 70 kg adult, that often means aiming for 70–100 grams per day depending on activity level. Benefits plateau beyond this range for most people. Extremely high intakes are unnecessary and may displace fibre-rich foods if not balanced.
Distribution Matters
Spreading protein across meals supports muscle protein synthesis, especially in older adults³. Instead of one large protein-heavy dinner and minimal intake earlier in the day, aim for roughly 25–35 grams per main meal.
What Does 30 Grams of Protein Actually Look Like?
Here are approximate examples of ~30 grams of protein:
Animal-based options:
• 130–140 g cooked chicken breast
• 140 g cooked salmon
• 4–5 large eggs
• 200 g Greek yoghurt (strained, high-protein variety)
• 120 g lean beef
Plant-based options:
• 250 g firm tofu
• 300 g cooked lentils (about 1½ cups)
• 200 g tempeh
• 2 cups cooked chickpeas
• 1 scoop high-quality plant protein powder (~30 g protein depending on brand)
Mixed meals:
• 3 eggs + 150 g Greek yoghurt
• Lentil bowl (1 cup lentils) + 100 g tofu
• 150 g cottage cheese + handful of nuts
These are approximations, but they make the abstract number tangible.
Protein Quality
Animal proteins generally contain all essential amino acids in sufficient proportions⁸. Plant proteins can meet requirements when total intake is adequate and sources are diversified⁸. Total daily intake is more important than obsessing over individual amino acids for most people.

The Reframe
Protein is not a trend. It is a structural requirement. Too little compromises muscle, metabolic stability and resilience. Excess without balance can crowd out fibre and plant diversity. Longevity does not require extremes. It requires adequacy.
Eat enough protein to preserve muscle.
Eat enough fibre to support the ecosystem.
Stability, not maximisation, is the goal.
References
¹ Institute of Medicine, 2005. Dietary reference intakes for energy, carbohydrate, fibre, fat, fatty acids, cholesterol, protein, and amino acids. National Academies Press. https://doi.org/10.17226/10490
² Cruz-Jentoft, A.J. et al., 2010. Sarcopenia: European consensus on definition and diagnosis. Age and Ageing, 39(4), pp.412–423. https://doi.org/10.1093/ageing/afq034
³ Bauer, J. et al., 2013. Evidence-based recommendations for optimal dietary protein intake in older people. Journal of the American Medical Directors Association, 14(8), pp.542–559. https://doi.org/10.1016/j.jamda.2013.05.021
⁴ Richter, E.A. and Hargreaves, M., 2013. Exercise, GLUT4, and skeletal muscle glucose uptake. Physiological Reviews, 93(3), pp.993–1017. https://doi.org/10.1152/physrev.00038.2012
⁵ Srikanthan, P. and Karlamangla, A.S., 2011. Relative muscle mass is inversely associated with insulin resistance. Journal of Clinical Endocrinology & Metabolism, 96(9), pp.2898–2903. https://doi.org/10.1210/jc.2011-0435
⁶ Leidy, H.J. et al., 2015. The role of protein in weight loss and maintenance. American Journal of Clinical Nutrition, 101(6), pp.1320S–1329S. https://doi.org/10.3945/ajcn.114.084038
⁷ Morton, R.W. et al., 2018. Protein supplementation to augment resistance training. British Journal of Sports Medicine, 52(6), pp.376–384. https://doi.org/10.1136/bjsports-2017-097608
⁸ FAO, 2013. Dietary protein quality evaluation in human nutrition. FAO Food and Nutrition Paper 92. https://openknowledge.fao.org/handle/20.500.14283/i3124e




