Working on the content for the third class of Live, Lose, and Learn (Lose Fat, Inches or Inflammation - 6 weeks to learn a new way of eating), I was reviewing the ways in which vegetable oils contribute to the obesity epidemic. Chief among those reasons has always been, in my mind, the instability of the polyunsaturated fatty acids, their omega 6 fatty acid content, and the likelihood that they are genetically modified. The fat instability creates free radicals which lead to inflammation which is fattening. Omega 6's - ditto, plus they interfere with more valuable omega 3 production from precursors in the food. Genetic modification: at the best it's an unknown, but there's some evidence to suggest that obesity is only one of the problems created by such tampering.
But stop the presses!! Elaine, one of my students in the class, alerted me to some research published here in Science News last fall. Vegetable oils stimulate appetite directly, similar to the "hunger-promoting endocannabinoids" stimulated by marijuana, without the attendant mood alteration. Just the munchies. What an interesting and revealing finding: that fried meal you chow down from a fast food stop or a well-meaning family member ("Aren't vegetable oils good for you?", the answer is: "Usually not, and never for frying") leaves you hungry for more.
The same article details some of the findings slowly implicating sugar-free alternatives as "obesogens", or causes of abnormal weight gain. The sweet taste has us expecting lots of calories, we prepare for them, and if they don't come in that food serving, well, we look for them elsewhere.