 Normal dietary fat contains mostly long @-@ chain triglycerides ( LCT ) . Medium @-@ chain triglycerides are more ketogenic than LCTs because they generate more ketones per unit of energy when metabolised . Their use allows for a diet with a lower proportion of fat and a greater proportion of protein and carbohydrate , leading to more food choices and larger portion sizes . The original MCT diet developed by Peter Huttenlocher in the 1970s derived 60 % of its calories from MCT oil . Consuming that quantity of MCT oil caused abdominal cramps , diarrhoea and vomiting in some children . A figure of 45 % is regarded as a balance between achieving good ketosis and minimising gastrointestinal complaints . The classical and modified MCT ketogenic diets are equally effective and differences in tolerability are not statistically significant . The MCT diet is less popular in the United States ; MCT oil is more expensive than other dietary fats and is not covered by insurance companies . 
