Poor dietary patterns leading to poorer health and increased health care use have affected people living in disadvantaged economic circumstances in the UK for decades, which many fear will be exacerbated due to the UK's current so-called ‘cost of living crisis’. The voices of experts by experience of those health and social inequalities are not routinely included in health improvement intervention development in relation to obesity prevention policy and programmes. Obesity is highly correlated with food insecurity experience in high-income country contexts (where food insecurity data are routinely collected) and is similarly socially patterned. Using a health equity lens, this review paper highlights qualitative research findings that have revealed the perspectives and direct experiences of people living with food insecurity, or those others supporting food-insecure households, that shed light on the role and influence of the socio-economic contextual factors food-insecure people live with day-to-day. Insights from qualitative research that have focused on the granular detail of day-to-day household resource management can help us understand not only how food insecurity differentially impacts individual household members, but also how behavioural responses/food coping strategies are playing into pathways that lead to avoidable ill health such as obesity, diabetes and other chronic health conditions, including mental health problems. This review paper concludes by discussing research and policy implications in relation to food-insecure households containing people with chronic health conditions, and for pregnant women and families with infants and very young children living in the UK today.