As you probably know, I just returned from Germany. One thing which always gets me, is that they appear to have even more overweight people than we do, including young boys! Such luxury can only be afforded by a society which doesn't need fit young men for the army duty.
When folks talk about this problem, they will usually mention sedentary lifestyle and low impulse control like inability to refrain from eating too much, but there are at least, two other factors to keep in mind.
Cheryl Mendelson mentions in her book Home Comforts (Scribner 1999, p. 51) that too many people nowadays don't have time to sir down and eat normal meals, but keep "grazing" during the day, which easily leads to overeating and health problems.
And then you have the disappearance of home cooking and the abundance of junk/fast food. It's not only important to sit down to a meal, but also to distinguish between real food vs inferior processed substitutes. I tried to find a nice picture illustrating this point, but instead, stumbled upon a health blog which defines real food and presents a 100 day of real food challenge.
I'd like to add a couple of suggestions of my own. You'll also need healthy fats. The number 1 healthy fat is virgin olive oil, cold pressed. And then you have butter/ghee/lard/beef tallow. Personally I mostly use olive oil and butter but last winter our supermarket also had lard and beef tallow which I tried for frying. Lard is definitely better and keeps better, too (imo).
Also considering whole grains, some people have trouble digesting them or are on a diet to avoid kidney stones. I think it's OK to cheat and use a mixture of flours for home baking, and in the supermarket, you could aim for Italian bread sorts with sour dough, or spelt bread. A local supermarket over here offers an artisan bread sort made of spelt which is nearly white. It's pricy so I only buy it now and then.
If you freeze white bread and then defrost and eat it, it will lower its GI. Toasting it has the same effect. Also, I think fruit jam is OK, especially if homemade. Or, aim for the new sorts with less sugar (but no artificial sweeteners).
The more real food you eat, the less you will crave all the junk stuff:)