If ever large amounts of carbohydrates enter the body, they are either immediately used for energy, or stored as glycogen, and the excess is quickly converted to triglycerides and stored in this form in adipose tissue. In humans, most triglycerides are formed in the liver, but very small amounts can also be formed in the adipose tissue itself. Triglycerides produced in the liver are transported mainly as very low density lipoproteins into adipose tissue, where they are stored. During triglyceride synthesis, only 15% of the potential energy in glucose is lost as heat. The remaining 85% is converted into energy by stored triglycerides.
Don't worry :)
The body stores fat if energy expenditure is less than its intake, and it does not matter whether you eat carbohydrates or not. Fats and proteins can also be converted to subcutaneous fat in excess. Carbohydrates are blamed for fat gain because they raise insulin levels and block lipolysis.