營養知識與飲食品質：台灣青壯年人口之研究

Nutrition Knowledge and Dietary Quality: Evidence from Taiwan's Working-Age Population

過去探討飲食行為的文獻多以蔬菜和水果類食物為主題，然而良好飲食品質應攝取不同類別食物、並且達到適當數量。本文建構飲食行為的理論模型，採用2004年至2008年台灣營養健康狀況變遷調查作為研究材料，以19歲以上、未滿65歲之樣本為對象，檢視台灣青壯人口在乳品、蔬菜、水果、蛋豆魚肉等四大類食物的攝取行為，討論營養知識與飲食品質的關聯及其他影響因素。考慮營養知識可能存在內生性疑慮，本研究選取工具變數、並採用兩階段的估計方法，以得到營養知識及其他因素的影響效果。分析結果顯示，蔬菜、水果類和蛋豆魚肉類食物，攝取不足的比例都有五成以上；乳品食物，未適當攝取的比例更是超過八成。越充足的營養知識，有助於乳品和水果等兩類食物攝取達到適當數量，但對於蔬菜類和蛋豆魚肉類則沒有顯著效果。另外，教育程度和經濟條件較好，對於飲食品質也有幫助。

Most of the previous literature on dietary behavior focuses on vegetables and fruits, yet good dietary quality should include an appropriate amount of diverse foods. This research thus constructs a theoretical model of dietary behavior based on the 2004-2008 Nutrition and Health Survey in Taiwan. The study examines the dietary behavior of Taiwan’s working-age population to explore the relationship between nutrition knowledge and dietary quality as well as other influencing factors. Considering the endogeneity of nutrition knowledge, we adopt instrumental variables and two-stage estimation to understand the effect of nutrition knowledge and other factors. The results show that over 50% of the population surveyed have an inadequate intake of vegetables, fruits, eggs, beans, fish, and meat, whereas over 80% are found to have an inadequate intake of dairy products. The subjects with more adequate nutrition knowledge are more likely to consume appropriate amounts of dairy products as well as fruits. However, nutrition knowledge has no significant effect on the consumption of vegetables, eggs, beans, fish, and meat. Lastly, higher education levels and better economic conditions have a positive effect on dietary quality.