The only number in the best-diet debate is 1.7–2.0g of protein per kg

Ask registered dietitians for the best diet for men and the first answer is "there isn't one". Re-ask it by goal and six candidates appear — and exactly one of them, the muscle-growth-and-recovery option, comes with a number: 1.7 to 2.0 grams of protein per kilogram of bodyweight per day.

In practice that is 136–160g a day at 80kg, 119–140g at 70kg, and 102–120g at 60kg. Choosing a diet reduces to one question: can this way of eating hit that total, today and every day?

What counts as a good diet?

The dietitians' definition of a quality diet was accessible, diverse, protein-rich, plant-forward and consistent — colourful fruit and vegetables, fibre, omega-rich fats. What marks a diet with room for improvement is poor access to nutrient-dense food, no nutrition education, inconsistent protein intake, and too much added sugar and heavily processed food. Note that protein appears there as a consistency problem, not a quantity one.

Which of the six can carry 1.7–2.0g/kg?

• Balanced performance eating — states the 1.7–2.0g/kg target outright, distributes calories and macros strategically through the day, and prioritises anti-inflammatory foods. It explicitly assumes a strength programme with progressive overload plus sleep and stress management, which makes it the most directly applicable to lifters.
• Mediterranean-style — fish, eggs, olive oil, wholegrain bread, and by design protein is a side rather than the centrepiece. Followed literally it undershoots the target, so fish and eggs have to be deliberately scaled up.
• Flexitarian, plant-forward — beans, nuts, wholegrains and produce most of the time, meat occasionally. Strong on micronutrients and fibre and linked to lower type 2 diabetes and heart disease risk, but the protein total has to be counted separately.
• Intermittent fasting — time-restricted eating. It works well for people who overconsume at night, cutting the surplus without depriving them during the day, but the narrower the window, the harder it is to fit 140g of protein into it.
• Volumetrics — soups, stews, chilis and salads that lower energy density by raising fluid content. Big plate, fewer calories, and food that takes a utensil and more time to eat. Powerful in a cut, actively unhelpful in a bulk.
• Eating around the world — rotating through cuisines to close nutrient gaps, presented as favourable for cholesterol, blood pressure and bodyweight markers.

So how do you choose?

Leslie Bonci, formerly a sports dietitian to the Kansas City Chiefs, framed it usefully: people need the "why" before they will try something, and it has to taste good enough to keep eating. The protein total is the fixed constraint; the container is whichever one you can run for years. Sustainability itself is covered in the diet you can sustain, and energy density in calorie density for lifters.

This also decides what you log. A diet's name never shows up in a Muscle Index score. The score is computed from Big 3 one-rep maxes plus bodyweight, age and height, so the only trace a diet leaves is the strength and bodyweight change its protein total produced. Log daily protein in grams, bodyweight, and your Big 3 numbers — not "week 4 of Mediterranean". Eight weeks in, whether the diet works for you shows up as a curve rather than a label. Total versus timing is covered in protein timing versus total intake.