WellByNumbers.

Rice cake (plain) vs Popcorn (air-popped)

Both count toward 30 plants a week.

Rice cake (plain)Popcorn (air-popped)
Protein · per 100 g7.0 g12.9 g
Carbs · per 100 g78.0 g77.8 g
Fat · per 100 g6.1 g4.5 g
Fiber · per 100 g2.1 g14.5 g
Energy · per 100 g405.0 kcal387.0 kcal
Protein · per 100 kcal1.7 g3.3 g
To hit 30 g protein429 g · 1736 kcal232 g · 897 kcal

The same three numbers, drawn

Protein / 100 g7.012.9Fiber / 100 g2.114.5Protein / 100 kcal1.73.3Rice cakePopcorn

What 30 g of protein looks like on a plate

429 gRice cake1736 kcal rides along232 gPopcorn897 kcal rides alongsquare area drawn to scale · grams needed for 30 g protein

Where the calories come from

protein 7%carbs 79%fat 14%
protein 13%carbs 77%fat 10%

The one-line verdict: Popcorn (air-popped) delivers 1.9× the protein per calorie of Rice cake (plain) (3.3 g vs 1.7 g per 100 kcal).

More protein / 100 g: PopcornMore fiber / 100 g: PopcornLighter per 100 g: PopcornSmaller 30 g portion: Popcorn

Swap in your own pair

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.