such intakes for a 59 kg jockey (the average pre-intervention weight of the jockey group tested here) would range from totalling 1 416 to 2 360 kcal.d − 1 for CHO alone. Additionally, considering that the daily energy expenditure of jockeys has been estimated at ~2 500 kcal.d − 1 [38] such intakes of CHO would therefore appear unrealistic for jockeys if they are to makeweight and/or reduce weight. The intervention prescribed in the present study incorporated a significant increase in dietary protein (2.5 g.kg.bw.d − 1). In a recent study, Bonomi et al. [5] observed that a high protein diet (1.2 g.kg.bw.d − 1) was necessary to maintain RMR following a weight-loss program in obese adults. These authors suggested that the maintenance of RMR on the high protein diet was a result of a reduction in the loss of lean muscle mass compared with the normal protein diet (0.8 g.kg.bw.d − 1). Similarly, Pasiakos and colleagues [25] reported that military personnel who consumed a protein intake of 2.4 g.kg.bw.d − 1 (an intake similar to our study) and 3 times the general recommended daily allowance (0.8 g.kg.bw.d − 1) for a 3 week period whilst in a 40 % daily energy deficit, had greater losses of fat mass than subjects on the recommended allowance. The high protein group also had the better maintenance of lean mass which is essential for maintaining metabolic rate during periods of energy deficit [31]. Additionally, maintaining lean mass during weight loss in athletes is important as not to compromise physical performance and