A 200 gram bowl of boiled or steamed white medium grain rice will contain, on average, 250 calories of energy. Most of this energy is derived from the rice's carbohydrate content.
Calories Aren't Always The Full Story
Remember, if you are trying to lose weight, it is important to check more than the calorific value of food. Calories represent energy, and we all need to consume food that gives us energy. It's what comes with that energy which is important. Lettuce is very low in calories but we wouldn't last long if all we ate was lettuce each day. Avoid food with high fat content, or foods high in energy but lacking in nutritional value (such as sugar). It's all about getting the right balance.
Learn how to know what to look for on the nutritional labels of food by watching this film: