Food losses occur at different stages of the food system. They are particularly observed during harvesting operations, during packaging and/or storage, transport and preliminary processing operations. This study was intended to make a diagnosis of the three sub-sectors (tomato, potato and cabbage), in terms of post-harvest losses (PHL) in order to assess the impact of these losses on the producer’s income and their impact on household food and nutrition security. Eight hundred and forty actors (producers, transporters, traders, processors) were involved in this study. Individual interviews, focus groups and weighings made it possible to collect the data. The results allowed to categorize the different types of PHL and determine their impact on the resilience of producers in facing household food and nutritional insecurity. The study also made it possible to identify the strategies adopted by producers to cope with these significant losses. These adaptation strategies depend on the stages of the supply chain. From the use of seeds adapted to the use of good cultural practices in the pre-harvest phase, the use of skilled labor for harvesting and good conservation practices, producers adapt with suitable provisions for transport of the goods and the search for a safe outlet. PHLs constitute a real risk for farmers, preventing them of fully benefiting from their work, while remaining an obstacle to the food and nutritional security of farmers and their households.