Nuts are significantly more land intensive per calorie than grains

I don't really agree.

Grains

• Call oats 4 t/ha, 389 kcal/100g
• Call rice 3.9 t/ha, 129 kcal/100g
• Call wheat 3.5 t/ha, 389 kcal/100g

Nuts

• Chestnuts get 8 t/ha – https://www.fao.org/4/Y4351E/y4351e0c.htm – and have about 196 kcal/100g
• Almonds get 4 t/ha – https://www.permaculturenews.org/2012/02/25/perennial-staple-crops-of-the-world/ – and have a mighty 578 kcal/100g
• Hazelnuts get 2.27 t/ha (2000lb/acre is conservative) and have 628 kcal/100g

Ranking in kcal/m²/year

• Almond 2312
• Chestnut 1568
• Oats 1556
• Hazelnut 1426
• Wheat 1152
• Rice 503