Having recently lived in Tokyo gave me a new perspective. I always struggled with losing weight in North America, but once I moved to Japan the weight came off very quickly.
What I think were the main contributing factors:
1) I walked everywhere, walked upstairs/downstairs at stations and work.
2) Small portions - your stomach gets used to ever-expanding portions. Portion control is unfortunately necessary. Miso soup is amazing for expanding rice in your stomach and making you feel very full for incredible low number of calories.
3) Good calories - There is, of course, processed foods in Japan, just not as in-your-face. Most grocery stores are super small and in your local market. Some only carry fresh produce and fish and meat. I cooked every meal in Japan. I did so in Canada too, the difference was that a lot of Japanese dishes are boiled / steamed instead of fried. I told one of my clients about Eggplant Parmesan and he looked nauseated. I picked up a Japanese cookbook and learned that they lightly boil/steam their eggplant.
4) I've heard that the more sugar you eat, the less flavor you can taste. I cut out all sugar while in Japan (except for alcoholic drinks - yum). For me, it was true that I could really taste food again. It's a hard sensation to describe something you hadn't been sensing before but were all of a sudden attune to. I have a feeling that this extra sugar leads to MORE extra sugar to taste said sugar and also to increased levels of 'flavor' in dishes. I've heard that the Japanese like their flavors subtle. This is definitely the experience I had in downtown Tokyo.
Anyway, it worked for me - I went from 135 lbs down to 112 lbs. Now, back in Canada, I notice advertisements for HUGE portions of everything.
Last anecdote, I got a Tall latte from the Starbucks in Shinagawa station and while walking to work I ran into a client who commented on my coffee, laughing, saying I had a big appetite. Considering a "Tall" is no big thing here, I both blushed and was taken aback. After that I really reconsidered if I needed so many fat and calories in my diet - don't we always upsize only because it's just a better deal, not because we actually want more food?
Just my thoughts!