We don’t need overconsumption at Thanksgiving to remind us that America is the home of the fat. That fact can be confirmed by standing on any street corner in any city of the country and watching Americans waddle by. Yet what many don’t understand is that one of the overriding causes of our weight problem has been our good fortune, which has been founded on the country remaining the land of the free.

Official statistics confirm casual observations. Since 1960, American adults have gained on average 26 pounds, which equal the weight of the largest turkey most families will have this Thanksgiving. This means that American adults now weigh nearly 3 million tons more than they would have weighed had they held to the average weight of 1960 adults.

The added tonnage equals the weight of 120,000 tractor-trailer trucks that, if put end to end, would stretch from Los Angeles to at least St. Louis, or 34 million 1960-equivalent adults.

These images of weight gain make it easy to understand why Americans began buying large SUVs in the 1980s, why rescue squads and hospitals have started using reinforced gurneys, why stadium and concert halls have had to widen their seats, and why Disney had to upgrade the carrying capacity of the boats in its hugely popular Small World ride—because it’s no longer a small world.

Americans are now each burning annually more than 2 billion more gallons of gasoline and jet fuel than would have been required had they not put on the added weight, according to research estimates. Of course, with the added weight and fuel consumption, there have been added tons of greenhouse gas emitted each year, as well as hundreds of billions of dollars of added medical costs.

Why has the country gotten so fat? The easy explanation—Americans eat too much and exercise too little—adds nothing that is not widely known.Embedded in the many explanations for the country’s weight gain is one surprising theme: in no small way, our weight problem is the reflection of our growing economic freedoms and a mirror image of our growing prosperity over the decades, which has, in turn, mirrored the spread of free-market economics and policies, as research studies have shown:

The average tariff barrier on American imports has dropped precipitously since the late 1940s, which has cheapened an array of imports (including foods) while elevating incomes.

With the drop in the real minimum wage from nearly $10 (in today’s dollars) in 1968 to just over $5 in 2007, businesses that relied on menial workers got a growing cost advantage—which gave a boost to fast-food restaurants that grew in density because they enabled all workers to buy their daily calorie intake for only minutes of work a day.

Women’s liberation provided women with a growing array of workplace opportunities at higher wages relative to men, which has increased relatively the full price of home-cooked meals (including the cost of meal preparation) and encouraged the consumption of preprocessed foods and restaurant meals, all of which tend to have more calories.

To meet market competition for Americans’ entertainment dollars, stadium and concert halls (and furniture manufacturers) have widened their seats. Fashion designers have designed clothing to camouflage Americans’ weight, making it easier (and less costly) for people to eat excessively.

The downfall of communism in the former Soviet Union and China freed 2 billion people dramatically to provide globally the variety of available foods, which has increased the count of meals and snacks.

The growing competitiveness of the world oil industry gave rise to a two-thirds drop in the real price of gas between 1913 and 1998, at which time the price was less than $1.40 a gallon. The drop in the real price of gas in the 1980s and 1990s caused Americans to drive more and to walk less, to go out to eat more—and order in calorie-packed meals more frequently.

The computer/telecommunication revolution also made calories cheaper and more widely available in varied forms from all corners of the globe.

A host of technological advances in mass production, storage, and distribution of foods—and the calories in them—has also added to the country’s average girth.

The people most concerned with the country’s weight gain—self-appointed “fat police”—have favored supposedly easy and direct policy solutions: tax and ban high-sugar and high-fat products. Such policy courses are a snare and delusion, especially if Americans’ cherished freedoms of choice, which are at the heart of the country’s economic engine, are to be preserved. But that is a topic that must of necessity be held for another commentary.