空腹 and 満腹: Hunger, fullness, and declining dessert
Compare hunger or an empty stomach with fullness. Read being full as the stated reason for declining dessert.
An empty stomach or hunger
空腹 means an empty stomach or hunger. 「空腹のまま走ったので、途中で力が出なくなった。」 reports running on an empty stomach and losing strength along the way. The action and result are connected in that sentence.
「焼きたてのパンの匂いで空腹を強く感じた。」 says the smell of freshly baked bread made the speaker intensely hungry. Hunger is the state felt.
The state of being full
満腹 means a full stomach or being full. 「昼食を食べすぎて満腹になった。」 reports eating too much at lunch and feeling full. The state follows that lunch.
「満腹だったのでデザートは断った。」 says the speaker was full and therefore declined dessert. 満腹だった states the reason for the refusal.
A state and a following action
空腹 and 満腹 contrast hunger with fullness. Hunger prompted by bread’s smell and fullness after lunch are the stated states; declining dessert is an action linked to one of them.
Declining dessert because of fullness does not mean lunch was skipped or appetite was entirely absent. The particular result of running on an empty stomach also does not establish a universal exercise or meal rule.
Why was dessert declined in 満腹だったのでデザートは断った?
Show the answer and why
The stated reason is being full. Read 満腹 as the state linked to the refusal, without replacing it with skipping lunch or having no appetite at all.