I don't understand people who force themselves to eat the excess food in their plate reminding themselves of the hungry kids in <insert backward African country name>, who hardly manage one square meal a day. I find this logic flawed at many levels.
Firstly, eating more isn't magically going to make food appear in front of the poor kids. The common argument against this logic is that the main intention behind this act is to punish oneself for taking too much to eat. I am not convinced. This approach attempts to correct one wrong by committing another. Far more people die in the world due to obesity related diseases than malnutrition. Forcing yourself to die early is a crime in itself, and a very poor choice of penance.
Secondly, if you really want to punish yourself, it is far better to see how much food you have wasted, and eat that much less in next meal. If there is a magical hand that makes extra food appear in front of needy kids, this has far better chance of success as against the eat-till-you-can't-swallow strategy. Again, I do not recommend it wholeheartedly. Reducing waste is a noble idea, and should be practiced by everyone. If your heart feels the pain and you take care not to consciously waste food, you don't need any penance.
This brings us to my experience which actually prompted me to write this post. The other day, I was eating with a few colleagues, and everyone ordered their food individually. This is a common practice in US and I have rarely seen people order common items for the group, which is usual in India. A lady ordered sea-food dish for herself, only to find that the quantity was too much for her to consume. The waitress had earlier indicated that the dish serves one person, so I can't blame her for the bad decision. As we finished our dishes, we saw her painstakingly trying to eat whatever she has taken in her plate. She eventually ate about 80% of the food and had to leave the rest. To-Go boxes were not an option as we were living in a hotel with no means to reheat the food later. I also had a similar story, but I ate all I could normally (without overeating) and left the rest. I felt sorry seeing her turn sick due to overeating. What struck me most was that she was punishing her for something that was no fault of hers. Making herself repent wasn't going to improve anything as there was no lesson to be learned. With the waitress lying to make sure people order more than they can consume, there was nothing she could have done before (or can do from now on) that will reduce the waste. I felt compelled to share my views, but eventually decided otherwise.
Unfortunately, eating in a buffet is hardly better than the condition described above because the very concept of buffet makes people overeat. If you paid 10 bucks for a meal, wouldn't you want to maximize the return on your investment? It takes a lot of discipline to have a balanced diet in a buffet. Also, while buffet makes it possible for people to be judicious about the quantity of food they take, it also creates a whole new class of people who have no clue of the amount of food they can consume and waste mountain-fulls. Not only buffets, eating in large groups also leads to gluttonous behavior.
I personally have always maintained the sanctity of my body and over-eating tends to remind me of using it as a dustbin. I try my best to avoid wasting food, but I don't punish myself if I fail.
I don't intend to use this post as a collection of dos-n-dont's of good eating behavior, so if you are interested I suggest Googling.