Background: Food diaries are commonly used to assess individual dietary intake in both the general and sporting populations. Despite the widespread use of such diaries, evidence suggests that individuals' self-reported energy intake frequently and substantially underestimate true energy intake. Purpose: To examine the use of the Microsoft SenseCam wearable camera to help more accurately report dietary intake within various sporting populations. Methods: In 2011, a total of 47 participants were recruited to take part in this study (17 trainee jockeys, 15 elite Gaelic footballers, and 15 healthy physically active university students). Participants wore a SenseCam for 1 day (from morning until night) while simultaneously keeping a 1-day food diary. Comparisons were made between the energy intake reported in the food diary alone and the food diary in conjunction with information gathered from the SenseCam. Data analysis was conducted in 2012. Results: Mean total calorie intake using diary alone and diary and SenseCam were 2349±827.9 kcals vs 2631±893.4 kcal for the trainee jockeys; 2600±521.9 kcal vs 3191±770.2 kcal for the Gaelic footballers, and 2237±318.5 kcal vs 2487±404.6 kcal for the university students. This represented a difference of 10.7% (p≤0.001); 17.7% (p≤0.001); and 10.1% (p≤0.01) among measurement methods for trainee jockeys, Gaelic footballers, and university students, respectively. Conclusions: Results from this first-generation study suggest that a more accurate estimate of total energy intake is provided when combining the use of a conventional food diary and a SenseCam. Additional information on portion size, forgotten foods, leftovers, and brand names can be obtained by using this novel sensing technology in conjunction with the diary, with improved dietary assessment a potential outcome.