"Certain food additives seem to promote overeating and weight gain by causing insulin resistance," says Maleskey. She points to out of Harvard University that focused on propionate, a food preservative, anti-browning agent and mold inhibitor found in manufactured foods with long shelf lives. Think: bread and other baked goods, pizza dough, cereal, condensed and dry milk, pasta and some processed meats. "It's a very long list," notes Maleskey; it's also in sports drinks, some diet foods, condiments, dried mushrooms, soups, beans and nut butters. Researchers studied mice and found that propionate can cause the liver to produce more sugar, which leads to greater levels of insulin in the blood, and "insulin drives hunger," says Maleskey. While Maleskey notes that more research needs to be done to compare propionate to other food additives, you can check labels for these names: calcium propionate, sodium propionate, proprionic acid, calcium salt or calcium dipropionate. "It certainly makes a good argument for baking your own bread," Maleskey says. Since not everyone has time for that, be sure to be a savvy label reader., Highly effective, well-researched ways lose weight include limiting processed foods, drinking more green tea, and taking probiotics., Ready to forget about dieting? Follow these research-supported natural weight-loss tips, all approved by in-house WeightWatchers experts..