The types of molecules that are primarily used for long-term energy storage in the lemur are lipids. What makes lipids effective for long-term energy storage is the fact that lipids are composed of long carbon-hydrogen bonds. As a result, they can store more energy in their bonds.
Carbohydrates can never be the answer because of the high ratio of carbon to oxygen bonds in their structure, particularly in their glycosidic linkages. Also, since carbohydrates are based on glucose, you only get fewer calories. To confirm this, you can decide to compare the metabolism of fatty acids and glucose.
Lipids can store more energy because there are a lot of calories stored in their structures. For instance, there are about 9 calories in one of fat and oils, while there are only about 4 calories in one gram of glucose. This explains why lemur ancestors were able to survive the trip to Madagascar without food.