This may sound a little harsh but I wouldn't be doing anything different.  If he doesn't eat his dinner he goes hungry, it wont be long before he realises that not eating isn't such a good idea.

We did a few seminars on eating for toddlers at our child resource centre and two things stick in my memory. 

1) No child who is offered food (assuming they aren't sick) has died of starvation

2) Food is one of the only things a toddler can control so the more attention you give it the more he is going to try and control it

So my advice is service up the meal and let him know that this is it, no arguing or coaxing or bribing.  If he doesn't eat it he doesn't get anything else.  If he says he is hungry an hour later too bad.  The time frame we used was 2 hours.  After 2 hours (except for dinner of course) we would then allow a snack.  It took 2 days for her to start eating properly.

Hmmm, someone told me once that as long as your child is eating all the food groups, even if it's one day at a time that it's ok.   Certainly, I would like to have your problem every now and then because my son is absolutely picky. He doesn't eat vegetables, doesn't eat beef (other than hamburger), doesn't eat things that look "funny".

He used to eat veggies when he was 18 months old and then just stopped eating them period. ARGH! 

Hi, my stepdaughters are both like this and when they lived with us a short while I did them an eating plan chart.I covered a place mat with brightly coloured card.On the card I split it into different sections-colour coded for each food type.I gave stickers for each mouthful of certain foods to co-ordinate with the food eaten.Green-peas,beans etc.Red-peppers,strawberries etc.Blue-bread,crackers and yellow if they ate three mouthfuls of each food.I sat their plate actually on the mat I made and sat with them while they ate to issue stickers.It took a while to get them to eat better but it did work eventually,Good Luck

All kids go through stages like this.  He could just be going through a slow growth period and doesn't have the same energy needs right now.  Go with it, and keep offering him what you have been.  He will get over it in the end and that garbage guts will be back in no time.