Several watershed discoveries have shaken up the food industry recently, some involving trans fats, others obesity, and most recently a finding that may finally explain the cause of the so-called French Paradox. Though the food world is filled with paradoxes, this French one , the ability of a nation to eat fatty foods and drink indulgently, yet remain thin and fashionable and seemingly immune to heart disease , has been of tremendous interest for years. Now a study from University of Pennsylvania and CNRS in Paris appears to provide some answers. The study examined all manner and form of food consumption, from mainstream foodservice to store-bought candy. The common thread was that portion sizes were significantly smaller in French restaurants and supermarkets than in their American counterparts. A candy bar, for instance, is reportedly 41 percent larger in the U.S. than in France; a hotdog 63 percent larger. Meanwhile, mean portion sizes in restaurants varied from 277 grams in Paris to 346 in Philadelphia. In quick-service and fine dining, Americans receive 25 percent more on their plates than the French do."Many studies have shown that if food is moderately palatable, people tend to consume what is put in front of them and generally consume more when offered more food," explains Paul Rozin, professor of psychology at University of Pennsylvania and lead author of the paper, featured in September's issue of Psychological Science. "Much discussion of the 'obesity epidemic' in the U.S. has focused on personal willpower, but our study shows that the environment also plays an important role and that people may be satisfied even if served less than they would normally eat."Though his may not be the final word on the French Paradox (which probably results from a combination of elements), Rozin becomes the newest member of a growing movement known as gastronomic introspection, which offers promising opportunities to food companies. Foremost, it enables them to lead consumers to healthier products. By undertaking studies that analyze specific product or dietary benefits, or merely informing consumers of relevant information from existing ones, companies have a better chance of gaining consumer trust and loyalty. (One caveat: the research should be sufficiently promising that it eventually bears out in related products -- whether yours or someone else's.) Point is, it won't be long before more and more consumers appoint science as their guide for eating. Many already have. But its today's youth market that probably will emerge as the issue's torchbearer, so there is still time to plan, but not a lot, since seniors and Baby Boomers already are scouring supermarket shelves for the answers to longevity. But seller beware: Greater gastronomic introspection will invariably lead to greater expectations on the part of consumers. Food companies are often notoriously slow to react, and ones that continue to rely on a portfolio that doesn't offer nutrition (as well as taste and satiety) will one day be lost in the wash of history.