Non-communicable diseases (NCD) have increased dramatically in developed and developing countries. Unhealthy diet is one of the major factors contributing to NCD development. Recent evidence has identified deterioration in aspects of dietary quality across many world regions, including low- and middle-income countries (LMIC). Most burdens of disease attributable to poor diet can be prevented or delayed as they occur prematurely. Therefore, it is important to identify and target unhealthy dietary behaviours in order to have the greatest impact. National dietary-related programmes have traditionally focused on micronutrient deficiency and food security and failed to acknowledge unhealthy dietary intakes as a risk factor that contributes to the development of NCD. Inadequate intakes of healthy foods and nutrients and excess intakes of unhealthy ones are commonly observed across the world, and efforts to reduce the double burden of micronutrient deficiency and unhealthy diets should be a particular focus for LMIC. Interventions and policies targeting whole populations are likely to be the most effective and sustainable, and should be prioritized. Population-based approaches such as health information and communication campaigns, fiscal measures such as taxes on sugar-sweetened beverages, direct restrictions and mandates, reformulation and improving the nutrient profile of food products, and standards regulating marketing to children can have significant and large impacts to improve diets and reduce the incidence of NCD. There is a need for more countries to implement population-based effective approaches to improve current diets.