The majority of the comments posted for this Guardian Word Of Mouth blog entry  about obesity rates and fast food places are about Japan, and how few people there are overweight. It seems that people latched on to this paragraph in particular:
There would appear to be more at play here than sheer wealth. Japan, which isn’t exactly poor, boasts over 3,000 McDonald’s restaurants, second in number only to the US, and is also home to many other fast food outlets to boot. Yet Japan has one of the lowest obesity rates in the world.
Eating and snacking in Japan is very convenient. In urban areas there are so many fast food places, food stalls, kombini or convenience stores stocked with all sorts of tempting and often fattening readymade food, and the world’s most advanced food and beverage vending machine industry. The snack food industry is fiercely competitive. And, unlike statements made by English press sources like this one  which implies that the fast food/junk food trend is some recent phenomenon, this state of affairs has been there for decades.
So at least in Japan the premise of the survey  cited doesn’t hold true.
That’s not to say that there aren’t overweight or even obese people in Japan. Japanese people, especially women, are as obsessed with diets as their counterparts in the U.S. or the U.K. Every day there’s a new ‘miracle diet’ popping up. Go to Japanese food sites and every other ad there is for some sort of weight loss scheme. There are increasing concerns about the unhealthiness of fast foods and convenience foods.
Still, I think that at least for a while, people in Japan will continue to stay relatively slim. Here are a couple of reasons:
A common complaint amongst Japanese people who go to live in another country, especially the U.S., is that a pretty substantial weight gain is almost inevitable. I haven’t been able to find any formal studies of this, but time and again I hear about people gaining around 15 to 20 pounds within a year or so after moving away from Japan. It’s not the Freshman 15, it’s the kaigai seikatsu (overseas living) 15. The author of Japanese Women Don’t Get Old Or Fat (my review here ) starts off with a personal anecdote about how she gained 25 pounds after moving to the U.S. One of the bestselling diet books in Japan, Tatakawanai daietto: waka musume wa kooshite yaseta!  (The Fight-free (struggle-free) diet: My daughter lost weight this way!) is based around the theme of a food and health journalist helping his daughter who came back “with a fat body” after a year of study in Arizona. (She’d gained about 10 kg, or 22 lb.)
This weight gained happened to me too. I wasn’t overweight at all until my family moved back to the U.S. when I was 17. Within the span of a year or so I went from around 50 kg to about 70kg. (I’m not actually sure what my starting weight was, since weight was not even an issue for me until I started to not fit in my clothes anymore!) I did lose a lot of it, but have since gained it back and more, hence my current efforts to get rid of the excess weight again!
Why did I gain 20 kg so easily? It comes down to fairly simple reasons: lack of unplanned exercise, lack of peer pressure, and the huge portions. Whenever my new school stressed me out (I hated that high school to be honest) I’d comfort myself with a bag of potato chips - the family size. We usually ate out as a family at local diners, where the club sandwiches could be stacked up about 15 inches high, and we started expecting home meal portions to be as big.
I think it is just tremendously hard to stay slim in the U.S. compared to other places I’ve lived, which is why the obesity rate is so high there. Public transportation is not that available except in a few cities, and people just don’t walk much anymore in the suburbs. So one has to make a special effort and set aside a specific time to get any exercise. Busy people aren’t always willing or able to do that. Portion sizes at restaurants and such are large, and I’m fairly sure many people will complain if they were drastically reduced.
And, despite the attention paid to ‘size zero’ celebrities and such, I just don’t believe there is that much peer or societal pressure to keep yourself slim. When the people around you are mostly neither slim nor fit, why bother?
I haven’t lived in the U.K. since I was a child, but whenever I’ve visited there in recent years I gotten the feeling that it was becoming more and more Americanized in lifestyle - more reliance on cars, bigger portions and so on. Add that to the fact that traditional British food can be quite high calorie (pies, fish and chips, and well, curries) it’s not too surprising to see obesity rates there soar.
As for Switzerland, it has some factors that help keep people slim, such as great public transportation, a natural tendency for people to get a little exercise, and reasonably sized portions. Also, people don’t really eat out as much here, or rely on takeaways/takeout and readymade meals.
The bottom line is that home cooking is really better for you all around, health and taste wise. And it’s the best way to take control of your own, and your family’s health. (And all the better if at some of that home cooking is Japanese…a reason to keep coming back here to Just Hungry. :))
[Update:] See the followup discussion, Does going back to your culinary roots make you healthier?