Tough topic! I have to cast my vote with the "let him make the high carb foods himself" group. Unless he plans to eat all his meals at McDonalds when he's grown, he'll need to learn some basic cooking skills eventually and at 14 he's plently old enough to learn. How about showing him your love, but teaching him to cook his own meals? That would also give you an opportunity to discuss basic nutrition and what a growing boy's body needs to be healthy and fit.
Of greater concern to me is the emotional blackmail and manipulation that appears to be going on. That needs to be nipped in the bud or it will only continue and in other areas besides breakfast as well. How you handle that is up to you, but if it were my kids, I'd take the direct approach and point out the behavior while it was happening saying, "What you are doing is called manipulation. It's not appropriate and I'm not buying it".
My girls are 8 and 9 and have learned by now that badgering and manipulation is the quickest way to get a very firm, "NO!" from me as well as time out (doesn't stop them from trying, but that behavior is becoming less frequent because it never gets them what they want). Disrespectul tones and attitudes will get them some time in their room to think about it as well. I'm not an overly harsh parent, but I will not be treated with disrespect by my children.
Kids are smart and will learn quickly the best way to get what they want, whether it be tears, tantrums, badgering or manipulation. Our job as a parent is to say yes when we can and no when what our kids want is not in their best interest. It's a dirty job, but if we don't do it, nobody else will.