Chiang Mai University, Chiang Mai, Thailand.
J Behav Med. 2012 Aug;35(4):443-51. doi: 10.1007/s10865-011-9373-1. Epub 2011 Aug 7.
Fruit and vegetable consumption represents a nutritional goal to prevent obesity and chronic illness. To change dietary behaviors, people must be motivated to do so, and they must translate their motivation into actual behavior. The present experiment aims at the psychological mechanisms that support such changes, with a particular focus on dietary self-efficacy and planning skills. A randomized controlled trial compared a theory-based psychological intervention with a health education session in 114 participants. Dependent variables were fruit and vegetable consumption, intention to consume more fruit and vegetables, planning to consume more, and dietary self-efficacy, assessed before the intervention, 1 week afterwards, and at 6-week follow up. Significant group by time interactions for all four dependent variables documented superior treatment effects for the psychological intervention group, with substantially higher scores at posttest and follow-up for the experimental group, although all students benefited from participation. To identify the contribution of the main intervention ingredients (self-efficacy and planning), regression analyses yielded mediator effects for these two factors. A social-cognitive intervention to improve fruit and vegetable consumption was superior to a knowledge-based education session. Self-efficacy and planning seem to play a major role in the mechanisms that facilitate dietary changes.
水果和蔬菜的消费代表了预防肥胖和慢性病的营养目标。为了改变饮食行为，人们必须有动力这样做，并且必须将他们的动力转化为实际行为。本实验旨在研究支持这些变化的心理机制，特别关注饮食自我效能感和计划技能。一项随机对照试验比较了基于理论的心理干预与 114 名参与者的健康教育课程。在干预前、1 周后和 6 周随访时，评估了水果和蔬菜的摄入量、增加摄入量的意图、计划增加摄入量和饮食自我效能感等因变量。所有四个因变量的组间时间交互作用均具有统计学意义，表明心理干预组的治疗效果更好，实验组在测试后和随访时的得分显著更高，尽管所有学生都从参与中受益。为了确定主要干预因素（自我效能感和计划）的贡献，回归分析得出了这两个因素的中介效应。提高水果和蔬菜摄入量的社会认知干预优于基于知识的教育课程。自我效能感和计划似乎在促进饮食变化的机制中起着重要作用。
