Tavan Mahya, Smith Nick W, Fletcher Andrew J, Hill Jeremy P, McNabb Warren C
Sustainable Nutrition Initiative®, Riddet Institute, Massey University, Palmerston North, New Zealand.
Fonterra Research and Development Centre, Palmerston North, New Zealand.
Front Nutr. 2025 Aug 1;12:1596081. doi: 10.3389/fnut.2025.1596081. eCollection 2025.
Over the past decade, there has been an increasing interest in the environmental sustainability of diets because food systems are responsible for a third of the anthropogenic greenhouse gas emissions (GHGE). However, less attention has been paid to the nutrient adequacy, consumer acceptability, and affordability of such diets. Such knowledge is particularly scarce in New Zealand, where approximately 40% of adults and 20% of children may live under severe to moderate food insecurity. The iOTA Model is a country-specific dietary optimisation tool designed to fill this gap by bringing the various aspects of diet sustainability together and providing evidence-based knowledge on not just the environmental impact of food but also its economic and nutritional sustainability. The iOTA Model was constructed using mixed integer linear programming by integrating New Zealand-specific dietary data. Features such as digestibility and bioavailability considerations have been incorporated as part of the iOTA Model, allowing for a more accurate estimation of nutrient supply. The model is available as an open-access tool and allows users to explore various dimensions of a sustainable diet. Eight optimisation scenarios, along with baseline diets, were investigated for adult males and females in New Zealand. Results showed that reducing dietary GHGE or price by approximately 80% was possible while meeting nutrient adequacy requirements. However, such diets deviated substantially from the baseline eating patterns, indicating lower consumer acceptability, and only included a limited variety of foods. On the contrary, diets with minimum deviation from baseline remained realistic while adhering to nutrient targets and reducing GHGE by 10 and 30% in female and male consumers aged 19-30 years, respectively, and weekly price remained below the baseline. Expansion of the model to additional countries and its open-access nature will allow independent dietary sustainability research through optimisation.
在过去十年中，人们对饮食的环境可持续性越来越感兴趣，因为食物系统产生的人为温室气体排放（GHGE）占三分之一。然而，此类饮食的营养充足性、消费者接受度和可承受性却较少受到关注。在新西兰，这类知识尤为匮乏，约40%的成年人和20%的儿童可能生活在严重至中度的粮食不安全状况下。iOTA模型是一种针对特定国家的饮食优化工具，旨在通过整合饮食可持续性的各个方面，并提供不仅关于食物对环境的影响，还包括其经济和营养可持续性的循证知识，来填补这一空白。iOTA模型是通过整合新西兰特定的饮食数据，使用混合整数线性规划构建的。诸如消化率和生物利用度等因素已被纳入iOTA模型，以便更准确地估计营养供应。该模型作为一个开放获取工具提供，允许用户探索可持续饮食的各个维度。针对新西兰成年男性和女性，研究了八个优化方案以及基线饮食。结果表明，在满足营养充足要求的同时，将饮食中的GHGE或价格降低约80%是可能的。然而，这类饮食与基线饮食模式有很大偏差，表明消费者接受度较低，并且只包含有限种类的食物。相反，与基线偏差最小的饮食在符合营养目标的同时仍然现实，19至30岁的女性和男性消费者的GHGE分别降低了10%和30%，每周价格仍低于基线。将该模型扩展到其他国家及其开放获取的性质将允许通过优化进行独立的饮食可持续性研究。
