Naseer F, et al. - Considering the recommendation of a preoperative weight loss of at least 5% in bariatric practice, researchers examined the efficacy of preoperative diets in achieving this 5% weight loss. This systematic literature search yielded only five diets that achieved ≥ 5% weight loss over varying durations and energy intakes. Compliance with a 700–1050 kcal (2929–4393 kJ) diet, consisting of moderate carbohydrate, high protein and low/moderate fat, for 3 weeks seemed efficacious in achieving 5% weight loss. This target could be achieved within a shorter duration via a low-carbohydrate diet (< 20 g/day).