It is common for boxers to try any means to lose weight in order to compete in a lighter weight division against smaller opponents.
Some boxers engage in extremely dangerous, rapid weight loss practices in the hours and days before weigh-ins.
Dr Stephen Selepe, who examines boxers on behalf of Boxing South Africa (BSA), said these practices can negatively affect performance and compromise boxers' health.
"Extreme dehydration, vomiting, starvation, laxative and diuretic use all significantly decrease performance and can be dangerous to health, so they are strongly discouraged."
Selepe said in order to get the most from training sessions, boxers need to ensure they are properly fuelled and hydrated.
"Ensuring intake of a wide variety of fruits and vegetables will provide much of the vitamins and minerals required to prevent illness and promote good health and recovery. Consuming adequate carbohydrate- containing foods such bread, grains and cereals, particularly before and after training sessions, will help fuel and promote recovery."
He said protein intake of meat, meat alternatives and dairy should be spread over the day in several moderate servings as well as after training, to best facilitate recovery and growth, rather than larger servings at one or two main meals.