I have a terrible habit of watching Youtube while I eat, and then one video turns to ten and I've wasted the entire day. I've tried just not watching it while I eat, but JUST eating is so incredibly boring that I cave in and turn it on regardless. I can't get any work done while eating either, since it takes me out of flow state when I'm working on something. Same with something like reading - it takes too much concentration to be done at the same time enjoyably.
Nothing usually. I prefer to focus on solely the task at hand, even if it's just eating. I find that when I try to watch TV or videos while eating, I will simply end up not concentrating on either and then take forever to finish my food, or get nothing out of what I was trying to watch.
Watching tv shows or Youtube too. But I'm limiting myself to one full episode. Or if YouTube, I select a video in the 20~30 minutes range so it will last for the whole meal + small break after. And then I stop.
If eating alone (I usually eat in family), I'm usually listening to music. Past that... it depends, really. If I'm treating myself I'll probably just eat and listen to music, but if it's a "normal" meal I might do it in the front of the computer or TV while browsing or watching stuff.
Breathe. Answer texts. Drink water/beer. Tell my wife it's delicious. Tell my stepson to please turn the volume down on whatever device he brought to the table.
Maybe you aren't eating the right foods? I am older so smaller calorie allocation now and honestly if I don't enjoy something I don't eat it. No room for crappy food.
Make or buy something healthy and so delicious you can enjoy it.
And music is a good accompaniment to food, that is engaging but won't make you mindlessly overeat.
For my work lunches, I either read a book or do some random sketching. Alternatively I go and buy something outside and go for a walk while eating my lunch. Some coworkers make a big thing about eating together, but I really can't do that every day.
At home I usually don't eat on my own.