High sugar and fat intake as well as low physical activity are known risk factors for the development of insulin resistance and type 2 diabetes. Particular chronic high glucose availability without high metabolic demand is thought to generate metabolic adaptations which heighten the risk for the development of type 2 diabetes. It is suggested that diet and exercise interventions should counteract and revert any accumulated health risks related to malnutrition and exercise deficiency. We therefore adopted a low-carbohydrate diet combined with high-intensity interval training (HIT) to improve insulin sensitivity, whole body metabolism and blood lipid profile in obese sedentary individuals. Obese sedentary subjects (n=19; BMI=323) were randomly assigned to an exercise – diet (DE) or diet only (D) group. Subjects (DE) trained three times a week on a cycle-ergometer (4 min 90% VO₂peak, 3 min rest, 10 bouts) for two weeks and followed a low carbohydrate diet (35% carbohydrates, 15% proteins, 50% fats, 33% unsaturated) while the D group followed the diet protocol only. Post intervention Oral Glucose Insulin Sensitivity (OGIS) was significantly improved in both groups (OGIS(ml x min^-1 x m-2): DE 37770 to 39668; D 36591 to 40487), and blood lipids (plasma triglycerides: DE 1.441.1 to 1.050.74, D 1.330.37 to 0.970.25; LDL: DE 2.970.74 to 2.760.66, D 3.430.63 to 3.170.69 and total cholesterol: DE 4.600.94 to 4.240.83, D 5.000.76 to 4.490.88 (mmol/l)) were significantly reduced. Moreover, RER was reduced in both groups (DE 0.910.06 to 0.880.06, D 0.920.07 to 0.860.07) while VO₂max was increased by 16% in the DE group only. It is evident that a low-carbohydrate diet alone can improve important parameters related to insulin resistance and type 2 diabetes while a combination of HIT and diet additionally mediate beneficial cardiovascular adaptations which are known to lower health risks in obese individuals.