[The Scientist (OP)]

I am currently experiencing problems like having frequent afternoon nap which wastes my time from doing other things. What is your advice on this? Is there anything that I can do about it? Thanks!

[Madidus_Scientia]

Exercise more I guess, but sleeping is no waste of time!

[tommya300]

I am currently experiencing problems like having frequent afternoon nap which wastes my time from doing other things. What is your advice on this? Is there anything that I can do about it? Thanks!

If this is an unusual occurrence that just have started, our bodies have ways of signaling there is a problem. Sometimes a short rest is needed, especially if your an older person...
See a doctor, a practitioner preferably, and explain precisely what, when and where; it happens.
Depression can occur and you can be unaware of it.
Heart problems, diabetic problems, sleep apnea, poor eating habits, vitamin deficiency or some exposure to certain environment, could be associated.
 If this frequent afternoon nap is affected by changing your diet and exercising, see a doctor anyway, it can be anything or nothing at all.

[MartinTheK]

Getting a check up to rule out a medical problem is a good idea.

Perhaps you have a problem with sleep hygiene if there is no medical problem. Ms. MartinTheK slept very poorly after eating a take-out helping of Lemon Chicken on Saturday night. 

Listen up people!

Fall in on this handout on sleep hygiene from Walter Reed Army Medical Center. Reveille is at 0600 and the first man I see yawning is headed for a date with the grease trap.

Dismissed.

http://wramc.army.mil/Patients/healthcare/medicine/pulmonary/resources/Sleep_Hygeine_Instructions.pdf