Changes in the frequency of food consumption by adults/elderly according to food insecurity: evidence from a longitudinal study in the northeastern semi-arid region, Brazil, 2011-2014

ABSTRACT Objective: To prospectively analyze changes in the frequency of individual food consumption of adults/elderly people according to different food insecurity outcomes over time. Methods: Population-based longitudinal study carried out in 2011 (358 individuals) and 2014 (301 individuals) in a municipality in the northeastern semi-arid region. The frequency of food consumption of 37 foods in adults/elderly was assessed using the Food Frequency Questionnaire and food insecurity using the Brazilian Food Insecurity Scale. Differences in the proportion of frequency of consumption of each food at baseline (2011) and follow-up (2014) were calculated according to longitudinal categories of change in food insecurity. The McNemar test for paired samples was applied to estimate differences between 2011 and 2014. Results: Among the individuals studied, 38.9% and 30.6% were classified in food security and food insecurity in the two periods (2011 and 2014), respectively, and 23.2% changed from food insecurity in 2011 to food security in 2014. Increase in the frequency of food consumed in the three groups of food insecurity outcomes. Only in the food insecurity group at both times, an increase in the consumption frequency of soft drinks and industrialized juices was observed. In the three groups, when comparing 2011 and 2014, there was an increase in the consumption of local agricultural foods, such as mangoes, sweet potatoes and a decrease in the consumption of pumpkin. Conclusion: Overcoming food insecurity results in positive changes in food consumption, and seasonality is a factor that promotes and limits food consumption.

摘要
目的：前瞻性分析不同粮食不安全结局随时间推移对成人及老年人个体食物消费频率的影响。
方法：本研究为基于人群的纵向研究，于2011年（纳入358名研究对象）与2014年（纳入301名研究对象）在东北半干旱地区的某一市镇开展。采用食物频率问卷（Food Frequency Questionnaire）评估成人及老年人的37种食物消费频率，并使用巴西粮食不安全量表（Brazilian Food Insecurity Scale）评估粮食不安全状况。根据粮食不安全状况的纵向变化类别，计算基线（2011年）与随访（2014年）时各类食物消费频率占比的差异。采用配对样本McNemar检验估计2011年与2014年之间的差异。
结果：在本研究纳入的对象中，分别有38.9%与30.6%的人群在两个研究周期内维持粮食安全与粮食不安全状态，另有23.2%的人群在2011年处于粮食不安全状态，至2014年转为粮食安全状态。三类粮食不安全结局组的食物消费频率均有所提升。仅在两个时间点均处于粮食不安全状态的组别中，观察到软饮料与工业加工果汁的消费频率上升。对比2011年与2014年，三类组别中本土农作物（如芒果、甘薯）的消费均有所增加，而南瓜的消费则有所下降。
结论：摆脱粮食不安全状态可使食物消费模式产生积极变化，而季节性是影响食物消费的促进与限制因素。