Your body can only store a limited amount of glucose in your body at a time, so if your body gets overloaded with it, it converts it into fat and stores it ON your body.
You can buy glucose bars to suck on, and eventually swallow at most shops nowadays. Glucose bars are used by people with low sugar in their blood.
Some animal fats are edible, examples of this are: lard (pig fat), fish oil, and butter or ghee. There are also edible plant fats: peanut, soya bean, sunflower, sesame, coconut, olive, and vegetable oils.
Your body needs glucose to survive so it uses respiration (see respiration), to create energy, so a more active person should eat more food. This is why many people are overweight, they eat too much, and don't use all the energy, so it gets converted to fat and stored on their body.

But this fat can be lost, see the Burn Fat;Exercise page.