This study investigated the energy intake and expenditure of professional adolescent academy-level soccer players during a competitive week. Over a seven day period that included four training days, two rest days and a match day, energy intake (self-reported weighed food diary and 24-h recall) and expenditure (tri-axial accelerometry) were recorded in 10 male players from a professional English Premier League club. The mean macronutrient composition of the dietary intake was 318 ˘ 24 g¨day´1 (5.6 ˘ 0.4 g¨kg´1 BM) carbohydrate, 86 ˘ 10 g¨day´1 (1.5 ˘ 0.2 g¨kg´1 BM) protein and 70 ˘ 7 g¨day´1 (1.2 ˘ 0.1 g¨kg´1 BM) fats, representing 55% ˘ 3%, 16% ˘ 1%, and 29% ˘ 2% of mean daily energy intake respectively. A mean daily energy deficit of´1302 ˘ 1662 kJ (p = 0.035) was observed between energy intake (9395 ˘ 1344 kJ) and energy expenditure (10679 ˘ 1026 kJ). Match days (´2278 ˘ 2307 kJ, p = 0.012) and heavy training days (´2114 ˘ 2257 kJ, p = 0.016) elicited the greatest deficits between intake and expenditure. In conclusion, the mean daily energy intake of professional adolescent academy-level soccer players was lower than the energy expended during a competitive week. The magnitudes of these deficits were greatest on match and heavy training days. These findings may have both short and long term implications on the performance and physical development of adolescent soccer players.