中国城乡居民饮食结构差异分析—基于营养级视角

ANALYSIS OF THE DIFFERENCES IN DIETARY STRUCTURE BASED ON HUMAN TROPHIC LEVELS BETWEEN CHINESE URBAN AND RURAL RESIDENTS

目的饮食结构指消费者所消费的食物种类和数量,而人类营养级(human trophic level,HTL)是反映复杂饮食结构的量化指标,本文利用HTL的概念揭示不同群体食品摄入变化的规律。方法本研究利用统计数据分别计算城乡居民的HTL,进而通过HTL的变化来研究城乡居民食品消费上的差异。结果我国城镇居民和农村居民的营养级从1995到2012年均呈现增长的态势,但是城乡差异仍然很大。农村居民的营养级从1995年的2.06增长到2012年的2.13,但是仍低于城镇居民1995年的2.18。进一步比较城乡居民5类食品的营养级贡献率,肉蛋奶贡献率的上升是导致二者营养级上升的主要原因,但是城镇居民肉蛋奶的贡献率上升比农村居民更为明显。居民收入和食品类支出同营养级的增长密切相关,当营养级达到2.25时,营养级逐步保持稳定,饮食结构呈现一种稳定的状态。同时,营养级的时间变化能够体现禽流感等食品安全问题对饮食结构的影响。结论人类营养级计算方便、易于理解,可以较为全面地反应居民饮食结构。

Objective Diet structure has been used to describe the type and quantity of food consumption by an individual or population. Human trophic level （HTL） can reflex complex dietary structure, and reveal the rule of food intake by different groups of people. Methods Using social statistical data, we calculated the HTL of urban residents and rural residents from 1995 to 2012, then analyzed the differences in food consumption between urban and rural residents. Results The HTL of both groups was increased between 1995 and 2012, but the gap was still large. The HTL of rural residents increased from 2.06 in 1995 to 2.13 in 2012, but it was still lower than urban residents （2.18） in 1995. Among the five compared foods we found that contribution rates of meat, eggs and milk were increased in both urban and rural residents, and resulted in the growth of their HTL. But the contribution rates of meat, eggs and milk in urban residents were more noticeable than in rural residents. Meanwhile, family income and food expenditures were closely related to HTL. But when the HTL reached 2.25, it reached a plateau, indicating the diet structure was stable. The change of HTL could reflect the food safety problems such as the impact of bird flu on the diet. Conclusion HTL is a good method to reflect diet structure and easy to be calculated and understood.