Food is on the tip of everyone's tongue these days. It even came up during Elena Kagan's Supreme Court hearings today. You can watch the video below. Senator Tom Coburn of Oklahoma asked if the government could pass a law mandating that people eat three fruits and three vegetables a day.
Coburn's question really was about the Commerce Clause, not food. The Constitution gives Congress the power "To regulate Commerce with foreign Nations, and among the several States, and with the Indian tribes". Despite the fact that the word "regulate" did not have the same meaning when it was written as it does today, the interstate portion of the clause has been interpreted by the Supreme Court (most definitively during the New Deal) to mean that the Federal Government can regulate anything that might possibly impact interstate trade. Essentially, anything and everything. Even what we eat, is Coburn's point.
Health care and food taxes/regulations are deeply intertwined. (Health and food are deeply intertwined.) We're increasingly seeing calls for soda taxes here in New York City. It's in line with other "sin taxes" (smoking, gambling), which politicians find easier to levy. Congress definitely has the power to tax. But the public willingness to accept food taxes and eventually, more restrictive federal regulations, will only increase as people feel that they are paying for other people's healthcare.
To a large extent we already do pay for other people's healthcare via Medicaid and Medicare — and even through private health insurance (where I am pooled with others, many less healthy than I, to arrive at a group rate). But the perception and reality of Peter paying for Paul's healthcare will only increase under the new health care legislation. And the implications are pretty easy to follow: If I'm paying for your healthcare, you better believe I'm going to tell you how to eat. This certainly won't come through prohibitions and mandates (no politician is that stupid), but through taxes and incentives.
What really scares me is that the long-time foundation of the USDA food pyramid has been a food group, grains, that humans basically did not eat prior to the Agricultural Revolution. And don't forget the decades long and deeply misguided War on Fat. Doesn't exactly inspire confidence!
The beauty of a system based more on individual responsibility is that people have the freedom to live as they please: healthy or unhealthy. Of course, then you have to let people face the consequences of their decisions, as if they were fully capable adults.