Background Childhood obesity is a global public health problem as a result of poor eating and activity behaviours. Periodically, taxation has been proposed as a strategy to modify food purchasing behaviour, and once again, there is growing interest in the feasibility of this approach towards obesity prevention. This article examines the outcomes of an expert panel that was convened to obtain consensus on 1) which foods are most problematic in terms of obesity if consumed during early childhood and 2) which foods would be amenable to taxation as a strategy to reduce consumption. A nominal group technique was facilitated with a panel of 12 Australian experts including nutrition professionals, academics and clinicians with an interest in childhood obesity. In addition to routine ranking analysis, transcripts were explored using thematic analysis to reveal the collective beliefs of the experts. Results The panel reached consensus about the types of foods that were problematic in terms of their consumption and contribution to early childhood obesity which included prepared foods consumed outside the home, high protein infant formula products and sugar-sweetened beverages. However of these food and beverage items, the panel only deemed sugar-sweetened beverages and infant formula to be potentially amenable to taxation. They also highlighted the importance of subsidizing fresh fruit and vegetables, whole and unprocessed foods and hence topic complexities resulted in panel discussion being extended beyond the central notion of taxation. Conclusions The panel identified several food groups that contributed to early childhood obesity but noted that these foods were not equally amenable to taxation. Results of this research should be considered during decision making and planning regarding population policy and regulation to reduce childhood obesity in the very early years.