Published: October 15, 2026 · 4 min read
Protein is the nutrient most closely tied to muscle and also one that raises a lot of questions, such as whether you need shakes or whether it harms your kidneys. This is what the International Society of Sports Nutrition (ISSN) says.
How much a day
For most people who train, the ISSN recommends 1.4 to 2.0 g of protein per kilo of body weight a day. For someone weighing 70 kilos, that’s 98 to 140 g.
If you have been training strength for a while and eat fewer calories than you burn, you may need more: 2.3 to 3.1 g per kilo.
How to spread it
The ISSN suggests spreading it across the day, every 3 or 4 hours, with about 20 to 40 g per meal. You don’t need exact counts: it’s enough for each main meal to include its portion.
Where to get it
The ISSN advises prioritising foods that provide all the essential amino acids, which are the ones muscle needs to build itself, such as meat, fish, eggs or dairy.
Not sure if you get enough protein from what you eat now?
Message me on WhatsApp (opens in a new tab)Do you need shakes?
No. According to the ISSN, you can get there with normal food. A shake is a practical way to do it, especially if you train a lot, but what counts is the daily total.
Is it bad for your kidneys?
The ISSN notes that published reviews find no sign of kidney or liver damage in healthy athletes and active people who eat more protein. Kidney disease is a different story: if that’s your case, talk to your doctor before changing your diet.
How I approach it
If you want to be a lion, you can’t eat like a little bird. But everyone has their own story, and that context shapes their relationship with food: the figures above are a starting point, and I adjust the plan to your day-to-day.
If you want me to fit your protein and the rest of your eating to your day-to-day and your training, we work on it together in nutrition coaching.
See nutrition coachingSources
This article is general information and does not replace a doctor’s advice. If you have an injury or an illness, or take medication, check with your doctor before changing your training or your diet.
Jaume Joan
Personal trainer in Sa Pobla (Mallorca) and Spanish natural bodybuilding champion (WNBF Spain, 2019).
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