M.F.
We've gone through this with both of ours (3 1/2 and 21 mo). It's really true about needing to offer something to a toddler a bunch of times before they try it. We didn't know what to do about this when our daughter was this age, so we just gave up trying. With our son, however, I decided to try something different. I'd heard that you have to offer something a lot, so when he suddenly quit eating broccoli, I decided not to say anything about it. I quit serving it for a while. Then I put it back on the grocery list for a couple weeks and served it to him once a day for 2 weeks. At the end of 2 weeks he actually picked it up and ate it. I never said a word to him about it...no coaxing or bribing, etc. We did the same thing when we introduced blueberries. At first he took them off his plate and set them on the table. I didn't say a word about it. Then he started playing with them, then after 2 weeks he ate a handfull. I was so amazed at our success that I told a friend about it and she tried the same thing with her daughter to get her to eat mango, and it worked!
I would encourage you not to fall into the trap of only feeding him hot dogs and macaroni just to get him to eat. He won't starve himself! We really had to have resolve on this, but we serve the kids exactly what we're eating. They can have as much or as little as they want of whatever is on the table. Granted, if we're having pork, green beans and mac n cheese, you can bet they hardly touch anything but the mac n cheese, but that's fine. The point is that I'm not preparing a special meal for the kids, and I'm not making any issue about food (as soon as I make it an issue, they make sure meal times are unpleasant). There have even been times when they hardly ate two bites of what was served, but every time this happens they clean their plates at the next meal no matter what it is! And you can bet that if they skip two meals, I could serve brussel sprouts at the next one and they'd eat it. Even if they refused to eat dinner, we sent them off to bed without it (though occasionally we let them drink a little milk before bed for fear they'll wake up in the middle of the night -- I don't want to lose sleep over their choice to not eat!). If they say they're hungry, I tell them, "I believe you! I'd be hungry too if I skipped dinner. Don't worry though, I'll fix you a wonderful breakfast in the morning." And I do! Pancakes, waffles, eggs, whatever -- and they eat every bite.
Good luck!