Have you seen the snacks that most people get when they go out? Muffins, chips, cheese sticks, sugary drinks, cookies, etc. There's a reason why those same snacks are provided in the office. My office has plenty of healthy choices, fresh fruits, vegetable trays, etc, but the unhealthy snacks are by far more popular.
"In large downtown cores like Toronto or New York I would say a stroll for a snack is more refreshing for productivity than mindlessly eating chips in front of the computer after a short run to the cafeteria."
Well yeah, but you're not really making the case for no snacks -- that's why the company provides them, so you don't have to take that stroll. Though even if snacks are provided, you don't have to eat them, you can still take your snack scroll if you want to.
When I worked in a suburban office park, leaving the office for a coffee was easier than it was now that I work in a high rise - I just went out the front door, walked across the court yard and had a nice coffee shop with a good selection of snacks. Now that I'm in a city high-rise, waiting for and riding the elevator takes almost as much time as it used to take to get coffee.
The company could pay you a dollar or two extra a day (snacks are cheap in bulk), but would you really notice that in your paycheck after taxes?