Discussion
In this paper, we describe the development and features of three android tablet-based Apps — the ACEC, FFQ, and IDR Apps used for dietary data collection in rural pregnant women and their infants. These Apps were used by trained community ANMs to collect reliable regional dietary information for the M-SAKHI study. A comprehensive and detailed description of methods used for dietary data collection in research studies that evaluate nutrition outcomes of an intervention is needed as it informs researchers regarding the reliability of the information collected and its replicability. High-quality data are essential to study the association between diet and health. Therefore, persistent efforts are needed to improve the existing dietary assessment methods and develop innovative tools to enable and standardise them. Recently, several studies have reported the successful use of android-based technologies for dietary data collection and assessment. These studies have concluded that technology-based data collection reduces errors and improves the quality and accuracy of dietary data and its analysis.Other types of software applications for dietary data collection are also available for nutrition research studies. They can be linked with external electronic gadgets such as armbands, smart watches or bar code readers from capturing data.Thus, apart from the advantages of automation, the ACEC App also offers the potential to gather dietary data from a wide range of culturally diverse cuisines worldwide due to its provision for entering new recipes. However, it is important to note that this hinges on the inclusion of the ingredients of these new recipes into the backend database. Likewise, the FFQ App can be employed for collecting dietary data from various countries, necessitating updates to the food list in the backend database to encompass new food items. The IDR App also has applicability to collect infant dietary data from different countries, contingent upon the utilisation of a backend database containing new recipe information. The scalability of the Apps makes them amenable for efficient dietary data collection from larger populations. Also, the learning curve associated with using the Apps is gradual, requiring less time to train the data collectors.These digital tools have proven to be suitable for large-scale studies that are technically complex but have low financial resources, high running costs and a small-time window to conduct field research. Mobile software applications that could be deployed on a large scale for a 24 h recall have reduced the project cost by up to 45 % compared to a traditional pen and paper-based approach.A limitation of this study was that the ACEC App's database solely encompasses ingredients from the central region of India. Additional work is needed to augment the database with ingredient data from different locations to enable the input of recipe information from diverse areas. Both the ACEC and IDR Apps were designed for energy calculations exclusively. Expanding these calculations to encompass other nutritional values falls outside the scope of the current study. The Apps currently offer support for only two languages: English and Marathi. Finally, an inherent challenge tied to accessing the Apps at zero cost revolves around intellectual property rights linked to the developer platform, which might potentially limit access to App usage without a paid subscription.