A major programme of irrigated rice extension in the Middle Senegal River Valley has further limited the river’s natural flooding in the floodplain (Waalo), initially reduced by drought. We conducted a transdisciplinary (TD) and gendered study in the region to explore links between agricultural biodiversity and family diets using a social analysis of women’s practices. The results showed how rice expansion impacts local agrobiodiversity, diet quality and the cultural way of life. Disappearance of the singular agropastoral and fishing system of the Senegal River Valley is profoundly modifying the landscape, limiting wooded riverine settings, and is undermining the traditional diversified flood-recession cropping system in the Waalo. This is causing an overconsumption of rice by reducing alternative food sources, such as sorghum, vegetables and animal products (fish, milk and meat). In particular, flood-recession sorghums are in danger of disappearing, yet they are more nutritious than rice and now sell for twice as much, or more. The way of life is being disrupted, notably sociabilities previously based on territorial complementarities, and women are disadvantaged in terms of recognition and added workload. Women’s groups have launched collective irrigated gardens, organic or not, only supported by the local NGO, but any surplus is hardly ever sold on the weekly markets in the neighbourhood. Moreover, this diet imbalance increases nutritional risk factors for health, such as vitamin and iron deficiencies, especially for women, hypertension and diabetes. We argue that, firstly, gendered TD experiences are relevant for documenting women’s activities in order for them to gain political support and, secondly, that targeting women’s care tasks gives more value and impact to TD research results.