Obesity is a growing major health concern affecting Australian adults and children. Sugar Sweetened Beverage (SSB) consumption is a considerable source of dietary sugar linked to obesity and several other health consequences. Poor decision-making and impulsivity have been implicated as potential routes towards excess SSB consumption and obesity. Decision-making and the ability to inhibit inappropriate behaviours is one of the last regions in the brain to mature. This makes children and emerging adults most vulnerable to poor decision-making skills. In addition, evidence points to impaired decision-making capacity resulting from a western style diet or one high in sugar. More impulsive individuals may be at risk of obesity via reduced self-control and inability to cease SSB consumption. It is possible that once started, more impulsive individuals may be less able to stop consuming desired foods such as SSB. As emerging adults and children are the highest consumers of SSB, it is important to understand and mitigate the factors driving SSB consumption. Most evidence to date linking SSB to impulsivity relies on self-report of SSB consumption and indirect measures of impulsivity. This thesis aimed to link impulsivity measures directly with SSB consumption. The primary aim of this thesis was to address limitations in the literature surrounding the role of impulsivity in SSB consumption and obesity; and to relate two naturalistic behavioural measures of impulsivity with SSB consumption, one involving SSB consumption directly, the other involving a delay of gratification in emerging adults and children. Study 1 (N =178) used a self-report measure of impulsivity to predict actual SSB consumption and delay of gratification in a group of emerging adults and to relate these with measures of obesity. Results indicated that self-report impulsivity predicted the delay of gratification measure. Self-reported impulsivity was not predictive of SSB consumption under experimental conditions, usual SSB consumption or obesity in this cohort. No mediating or moderating effect of usual SSB consumption on the relationship between impulsivity and obesity was found. Study 2 (N = 107) addressed potential methodological limitations and replicated Study 1 findings in a second sample of first year university students. Results from Study 2 were similar to those of Study 1 and substituting soda water as the control and providing regular reminders to participants for the final reward created additional confounds. The second aim of this thesis was to investigate the role of parents in regulating their child’s SSB consumption. Parenting style can contribute to determining their child’s attitude and consumption of SSB. However, there is limited evidence examining the role of parenting, parental impulsivity and child impulsivity as factors influencing SSB consumption and the resultant pathway to obesity. Study 3 (N =56) used the methodology from Study 1 in a sample of children as the cohort of interest. Study 3 tested the self-report impulsivity measure against the two behavioural measures with children aged 10-12 years. Study 3 also accounted for parenting style and compared parent - child impulsivity to further understand the factors leading to excess SSB consumption and pathway to obesity. Although the studies did not demonstrate the predictive capacity of self-report impulsivity over the two behavioural measures of impulsivity, several potential reasons were discussed including self-selection bias. Investigation of the role of parenting style revealed that negative aspects such as poor supervision are risk factors for their children’s impulsivity and SSB consumption. These results have implications for encouraging parental involvement in their child’s food choices worthy of a targeted intervention. The results of this thesis provide a promising basis for future research to target at-risk children and emerging adults, and to encourage policy makers, educators and parents to limit SSB access to young, developing brains.