Tallywell.

Rolled oats (dry) vs Buckwheat (cooked)

Both count toward 30 plants a week.

Rolled oats (dry)Buckwheat (cooked)
Protein · per 100 g13.2 g3.4 g
Fiber · per 100 g10.1 g2.7 g
Energy · per 100 g379 kcal92 kcal
Protein · per 100 kcal3.5 g3.7 g
To hit 30 g protein227 g · 861 kcal882 g · 812 kcal

Bold marks the better side of each row. "Per 100 kcal" answers the density question — which food delivers more protein for the energy it costs. Portion row is computed live from the same USDA base values shown on each food page.