Jhum is a swidden agriculture agroforestry system indigenous to India. It enriches crop diversity and dietary diversity, helping to ensure food security and nutrition. However, jhum is now being rapidly abandoned in favour of intensive agriculture, often involving monoculture. Such changes in land use are a major threat to local food security. Based on a survey of 97 households in four villages of the West Garo Hills in the state of Meghalaya in north-eastern India, jhum and the corresponding food diversity (as maintained by the Garo indigenous communities) were examined. We used a mixed-methods approach to quantify the contribution to dietary diversity, and food and nutritional security. The jhum system of farming comprised of 39 crops and four indigenous breeds of livestock, which were categorized into five core food groups that sustain nutritional security and the food culture of indigenous people. The traditional food basket is supplemented with wild edible plants collected from fringes of forest and jhum fallows that are part of the system. The traditional foods of Garo communities, that are drawn almost entirely from locally available sources, are a significant part of local culture, and serve to reinforce conservation of biodiversity. The traditional food diversity guarded by indigenous people can serve as a basis for designing and implementing public policies aimed at ensuring food security of those regions that practise such systems, and more widely. Given this close interdependence between agrobiodiversity, culture, and livelihoods prevailing in the community, the present study recommended for keeping some area under traditional land use, supplemented with fresh measures to ensure its economic viability.