GLUCOSE AND LIPID HOMEOSTASIS AND INFLAMMATION IN HUMANS FOLLOWING AN ISOCALORIC KETOGENIC DIET

OBJECTIVE: To measure changes in glucose, lipid, and inflammation parameters after transitioning from a baseline diet (BD) to an isocaloric ketogenic diet (KD). METHODS: Glucose and lipid homeostasis and inflammation were studied in 17 men (BMI 25–35 kg/m(2)) during 4 weeks of a BD (15% protein, 50% carbohydrate, 35% fat) followed by 4 weeks of an isocaloric KD (15% protein, 5% carbohydrate, 80% fat). Postprandial responses were assessed following mixed meal tests (MMT) matched to compositions of the BD (control meal, CM) and KD (ketogenic meal, KM). RESULTS: Fasting ketones, glycerol, FFA, glucagon, adiponectin, GIP, total and LDL cholesterol, and CRP were significantly increased on the KD. Fasting insulin, C-peptide, triglycerides, and FGF-21 were significantly decreased. During the KD, glucose area under the curve (AUC) was significantly higher with both test meals and insulin AUC was significantly higher only for the CM. Analyses of glucose homeostasis suggested that the KD insulin sensitivity was decreased during the CM but increased during the KM. Insulin-mediated anti-lipolysis was decreased on the KD regardless of meal type. CONCLUSIONS: Switching to the KD was associated with increased cholesterol and inflammatory markers, decreased triglycerides and decreased insulin-mediated anti-lipolysis. Glucose homeostasis parameters were diet- and test meal-dependent.