One thing I had to get used to when I first started coming to France was the fact that everything is closed at lunch, making it impossible to get anything done between 12 and 2pm. While I'm certainly better at planning my errands to account for this, I still find it frustrating and all tasks seem to take much longer as a result. Another part of me admires this regard for the need to have a proper meal and take time out of the day to relax a bit. Here, there is no question of staggering lunches so as to keep services open; everybody takes their lunch at the same time, lights are turned off and gates are locked closed. Period. Even on the highway, you can see cars in little pull-offs and families gathered around the car (or a picnic table if they're lucky) sharing a meal. As soon as it's midday, it's time to stop what you're doing, wherever you're doing it, and sit down to lunch.
Most people still eat a big meal at lunch, with meat, vegetables, salad, cheese and dessert (and wine!). I tend to stick to a homemade sandwich or salad, and when French people find out that this is what I eat for lunch, they say that it's very unhealthy! I've never thought of sandwiches as unhealthy, but perhaps they're thinking of the 16" white baguette sandwich filled with cheese, ham, butter and mayonnaise. Personally, if I have a big meal at lunch, I feel really lethargic afterwards and need a nap, so I can't imagine changing this particular habit while working.
A part of me would like to see France have the same business and banking hours as Canada, but I can also see that it would be a shame to lose this part of French culture. It's admirable (in a way) to not cave in to the 24/7 mentality of the world (unless you're trying to get something done!).