Claim: There is a classic diet called Ketogenic diet.

The ketogenic diet is a high-fat , adequate-protein , low-carbohydrate diet that in medicine is used primarily to treat difficult-to-control -LRB- refractory -RRB- epilepsy in children . The diet forces the body to burn fats rather than carbohydrates . Normally , the carbohydrates contained in food are converted into glucose , which is then transported around the body and is particularly important in fueling brain-function . However , if there is very little carbohydrate in the diet , the liver converts fat into fatty acids and ketone bodies . The ketone bodies pass into the brain and replace glucose as an energy source . An elevated level of ketone bodies in the blood , a state known as ketosis , leads to a reduction in the frequency of epileptic seizures . Almost half of children , and young people , with epilepsy who have tried some form of this diet saw the number of seizures drop by at least half , and the effect persists even after discontinuing the diet . There is some evidence that adults with epilepsy may benefit from the diet , and that a less strict regimen , such as a modified Atkins diet , is similarly effective . The most common adverse effect is constipation , affecting about 30 % of patients -- this was due to fluid restriction , which was once a feature of the diet , but this led to increased risk of kidney stones , and is no longer considered beneficial .   The original therapeutic diet for paediatric epilepsy provides just enough protein for body growth and repair , and sufficient calories to maintain the correct weight for age and height . The classic therapeutic ketogenic diet was developed for treatment of paediatric epilepsy in the 1920s and was widely used into the next decade , but its popularity waned with the introduction of effective anticonvulsant drugs . This classic ketogenic diet contains a 4:1 ratio by weight of fat to combined protein and carbohydrate . This is achieved by excluding high-carbohydrate foods such as starchy fruits and vegetables , bread , pasta , grains and sugar , while increasing the consumption of foods high in fat such as nuts , cream and butter . Most dietary fat is made of molecules called long-chain triglycerides -LRB- LCTs -RRB- . However , medium-chain triglycerides -LRB- MCTs -RRB- -- made from fatty acids with shorter carbon chains than LCTs -- are more ketogenic . A variant of the classic diet known as the MCT ketogenic diet uses a form of coconut oil , which is rich in MCTs , to provide around half the calories . As less overall fat is needed in this variant of the diet , a greater proportion of carbohydrate and protein can be consumed , allowing a greater variety of food choices .   In the mid-1990s , Hollywood producer Jim Abrahams , whose son 's severe epilepsy was effectively controlled by the diet , created the Charlie Foundation to promote it . Publicity included an appearance on NBC 's Dateline programme and ... First Do No Harm -LRB- 1997 -RRB- , a made-for-television film starring Meryl Streep . The foundation sponsored a multicentre research study , the results of which -- announced in 1996 -- marked the beginning of renewed scientific interest in the diet .   Clinical trials and studies in animal models -LRB- including C. elegans -RRB- suggest that ketogenic diets provide neuroprotective and disease-modifying benefits for a number of adult neurodegenerative disorders . As of 2012 , there is limited clinical trial data in these areas , and , outside of paediatric epilepsy , use of the ketogenic diet remains at the research stage .