Since I've become older, I prefer to eat fish and vegetables rather than the heavy-to-digest meat.
With age, I've come to find that fish and vegetables are more tasty than the heavy meat.
ご質問ありがとうございます。
① "Since I've become older,"＝「年を取って、」
"I prefer to eat fish and vegetables rather than the heavy-to-digest meat."＝「魚や野菜を好むようになった。消化し難い肉よりも。」
② "With age, I've come to find that fish and vegetables are more tasty than the heavy meat."＝「年とともに、魚や野菜の方が美味しいと感じるようになった、こってりした肉よりも。」
ご参考になると幸いです。
アメリカ合衆国 
