Just how dishonest is your dc a d when should you worry?

[KinseyWinsey]

My ds is 15.

He lies a lot.

He lies about whether he's done his revision.

What time he went to bed.

What he said yesterday.

What he's eaten or not.

What arrangement we agreed upon.

Even when the facts and proof are right there, he will still lie and lie.

I start to doubt myself in the face of such lies. Then I check myself and remember the truth.

I find it astonishing. Especially over the stuff that isn't a big deal.

Is it something to be worried about? This chronic dishonesty.

He may be lying as he doesn’t want to hear the consequences of telling the truth to you .
At 15 he should really be quite independent and doing his own revision and able to eat when he likes etc and maybe he finds you overbearing ?
I would lay off the questioning a bit and give him space to be more independent. Then he might not lie as much

Maybe he finds it too controlling at his age to be asked when he sleeps and eats, he will do just not when you want him to, he's becoming independent at this age.

I used to tell lies like that when I was that age. I lied because I was utterly terrified of my parents. I was used as an emotional and physical punch bag and I would never know what would set them off.
Not saying you do anything like this OP but are you quite strict? He could be worried about disappointing you and then getting into trouble.

My son used to lie about things he was scared of admitting. For example, at one point I discovered that he'd not been to piano lessons for several weeks and had instead been going and sitting for an hour at the library. Turned out the piano teacher was crap and he hated going but didn't want to admit it. Cancelled those lessons and got a nicer teacher.

There were a few similar things. He was more honest when I made it clear that I wasn't going to get angry about stuff, or "tell" on him to other people. But basically it was anxiety driving most of it, and feeling embarrassed at not being good enough. In the end I managed to get him some therapy, and he's now more self-confident, can say what he thinks and admit any mistakes, and doesn't need to lie.

My eldest is younger but lies, quite easily. I know it's because I have been strict and too harsh when he was younger and he would rather lie than have me go on about something he had done. His dad was/is similar. I have no doubt the lying is a product of his upbringing so I'm doing my best to be more easy going and back off.

Plus whether a 15 year old has eaten or done homework is a bit old to be quizzed on. I ask mine if he has homework and has he thought about when he will do it but that's it. I don't get involved as it's up to him. If he doesn't do it he can suffer the consequences from school. I also found he was lying about eating his lunch and he was throwing it away. We now have an agreement that I'm not going to force him to take lunch, it's his choice instead. These are lessons they need to learn without a strict parent breathing down their neck.