Subsistence farmers in sub-Saharan Africa aim for strategies to enhance their food security. Implementing upgrading strategies (UPS) must be assessed prior to and during implementation. The objective of this paper was to analyze and compare ex-ante and mid-term assessments of two food-securing UPS (rainwater harvesting and micro fertilization, improved cooking stoves) conducted with local stakeholders from four rural villages in Tanzania. We utilized locally developed food security criteria developed under the Framework of Participatory Impact Assessment (FoPIA). Focus group discussions were used to anticipate (ex-ante) and reflect (mid-term evaluation) the likely effects of selected UPS. Overall, the stakeholders’ assessment scores declined from the ex-ante to the mid-term assessment; in particular, the economic criteria decreased, followed by the social criteria. Four critical factors were identified: 1) rainfall-related problems; 2) workload; 3) managerial performance; and 4) social conflicts. Assessment differences were found within the villages, between regions and across villages. Combining both the assessment scores and the farmers’ explanations during assessments provides the key to optimizing the food-securing potential of UPS.