Tinker Lesley F, Perri Michael G, Patterson Ruth E, Bowen Deborah J, McIntosh Martin, Parker Linda Miller, Sevick Mary Ann, Wodarski Lois Ann
Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA.
J Am Diet Assoc. 2002 Jun;102(6):789-800, 888. doi: 10.1016/s0002-8223(02)90178-1.
To examine whether the effects of physical and emotional status on adherance to a low-fat (20% energy) dietary pattern are mediated by participation in an intervention program (attending sessions and self-monitoring).
The Baron and Kenny mediator model, a series of 4 regression analyses, was used to evaluate whether: a) physical and emotional status predicted program participation, b) program participation predicted dietary adherence, c) physical and emotional status factors predicted dietary adherence, and, ultimately d) the effects of physical and emotional status on dietary adherence were mediated by program participation.
SUBJECTS/SETTING: Data from 13,277 postmenopausal women randomly assigned to the low-fat intervention arm of the Women's Health Initiative Dietary Modification Trial.
The nutrition goals for women randomly assigned to the low-fat intervention were to reduce total fat intake to 20% or less of energy from fat and to consume 5 or more fruit/vegetable servings daily and 6 or more grain servings daily.
Year 1 program participation (degree of attending group sessions and submitting fat scores) and adherence to the low-fat dietary pattern (percent energy from fat) as predicted by baseline physical and emotional status (eight SF-36 Health Survey subscales).
Participating in the dietary intervention program reduced (mediated) the negative effect of poorer mental health on dietary adherence by 15%. Additional findings included that a 10% increase in physical functioning increased session attendance by 0.4% (P<.001) and a 10% increase in mental health predicted a decrease in percent energy from fat of 0.3% (P<.001). Program participation had a marked effect on dietary adherence: a 10% increase in session attendance predicted a 1.2% decrease in percent energy from fat (P<.001).
APPLICATIONS/CONCLUSIONS: Understanding and using instruments to assess the physical and emotional status of a target population will help dietetic professionals promote healthful dietary change and maintenance.
探讨身体和情绪状况对低脂（占能量的20%）饮食模式依从性的影响是否通过参与干预项目（参加课程和自我监测）来介导。
采用Baron和Kenny中介模型，即一系列4次回归分析，来评估：a）身体和情绪状况是否预测项目参与度，b）项目参与度是否预测饮食依从性，c）身体和情绪状况因素是否预测饮食依从性，以及最终d）身体和情绪状况对饮食依从性的影响是否由项目参与介导。
研究对象/研究背景：来自13277名绝经后女性的数据，这些女性被随机分配到妇女健康倡议饮食改良试验的低脂干预组。
随机分配到低脂干预组的女性的营养目标是将总脂肪摄入量减少至占能量的20%或更低，并每天食用5份或更多份水果/蔬菜以及6份或更多份谷物。
第1年的项目参与度（参加小组课程和提交脂肪得分的程度）以及由基线身体和情绪状况（8个SF - 36健康调查子量表）预测的对低脂饮食模式的依从性（脂肪提供的能量百分比）。
参与饮食干预项目减少（介导）了较差心理健康对饮食依从性的负面影响的15%。其他研究结果包括身体功能提高10%会使课程出勤率提高0.4%（P <.001），心理健康提高10%预计会使脂肪提供的能量百分比降低0.3%（P <.001）。项目参与对饮食依从性有显著影响：课程出勤率提高10%预计会使脂肪提供的能量百分比降低1.2%（P <.001）。
应用/结论：理解并使用工具评估目标人群的身体和情绪状况将有助于营养专业人员促进健康的饮食改变和维持。
