Sure, getting enough sleep is the biggest way to beat the 4:00 yawning session (I swear, there is something about this time--weirdly, I could fall asleep at 4 p.m. everyday!), but did you know that several other surprising things could be making you sleepy? Here are some unlikely yawn-inducers...
Yawning? 6 Surprising Reasons Why You're Exhausted - Healthy Living on Shine

    

Those ideas all make sense to me. I don't think I've ever had a UTI but I can vouch for all those other symptoms. I know that when I have dieted in the past, I've had a real problem with sleepiness.

Wow, I would have never have thought that a UTI could cause you to yawn. I only thought it caused you to cuss and be in pain. Some of the others make sense though.

I agree that I could go to sleep at 4 everyday. Has anyone seen those emerald nut commercials, I think that could be me?

Stress and work overload can also make you tired. Also, if you have depression, this can cause tiredness. For me oddly, after I finish working out I get sleepy.

Yes it sound genuine to me...special Diet...that matters allot..i always feel sleep if i have rice in lunch

well i am trying not to yawn after 4 pm in office and keeping in mind those facts...and up to some instance it succeeded...