Some personal choices to take action on:
Buy local produce, and let your local supermarket or grocer know this. Educate others. It saves on all of the transport emissions from air or truck freight of goods.
Cut back on electrical, and gas usage. Most homes I have visited in the US have multiple TVs, each family member has more than two computers, or smartphones and tablets.
Car pool. Buy economy cars, not SUVs. Walk. Run. Cycle to work. Americans can sure use the exercise and diet changes. (DISCLAIMER: I am an American, born and raised). I was working physically 9-11 hours a day in Las Vegas, and cycling 6 miles to and from the construction site each day. Obese co-workers called me crazy. Then before Christmas 2009, I gave CPR to a 35 year old man with two kids and new born baby on the site, but he died before he hit the ground from a massive coronary. He had just arrived to work with Dunkin Donuts coffee and donuts in a bag and dropped. He stopped taking his heart medication his wife said.
After being in SE Asia for 8 years, and returning to the US, my perception of just how obese Americans have become is striking. I have been living in the rice fields of East Java, so it is even more stark.
I am a libertarian and mainly capitalist, so I don't wish any of this forced on anyone through legislation, and people are free to continue in their ways; I am just presenting some perceptions that might make people think twice about their lifestyles. They can choose what they want, but their are consequences locally and globally.
For me, I have not felt healthier, and less stressed, and I will take these tools, perceptions and lifestyle choices back with me to the US. I went vegetarian 3 years ago, haven't drank alcohol in 7 years, and I run and exercise everyday. I know it might be harder when I get back, but I have built a solid foundation to continue there anyways.
Big country-wide, policy changes need to be thought out economically, since we can only throw so much money and manpower at a particular solution. Some of the more rational choices may seem to go against feelings, and unfortunately, those who want the vote, vote for what makes people feel happier, not what's probably best for them and the country as a whole.