By Lisa Freedman for DETAILS.(photo: John Ashley/Flickr)Carrying a spare tire around your belly' You're not alone: Fifty-four percent of U.S. adults now have abdominal obesity, up from 46 percent in 2000, according to a recent report in the Journal of the American Medical Association. If you fall into that category (male abs are considered fat if the waistline measures more than 40 inches), it's time to consider cutting down your consumption of these five foods:Refined grainsNot sure what a refined grain is' It's an ingredient found in foods like white rice, white bread, and regular white pasta. The unrefined stuff (whole wheat, brown rice and quinoa) is always healthier. Pennsylvania State University researchers found that people who ate whole grains in addition to keeping a healthy diet--of fruits, vegetables, low-fat dairy and protein--lost more weight from the abdominal area the group of people who kept the same healthy diet but ate all refined grains.Potato productsA study published in the New England Journal of Medicine followed the weight changes of more than 120,000 men and women for up to 20 years. The participants were checked every four years and, on average, they gained 3.35 pounds each time--so almost 17 pounds by the time the study was finished. The foods associated with the greatest weight gain' You guessed it--potato chips and potatoes.Read more: The 5 Best Ways to Lose Belly FatRed and processed meatThe same 20-year study found that people who ate more red and processed meat gained weight, too--about one extra pound every four years. In another study, published in the American Journal of Clinical Nutrition, researchers worked with more than 370,000 people and found that folks who ate the equivalent of a small steak a day gained about five pounds in five years.FrostingThose cupcakes your coworker makes for special occasions' Yeah, don't eat them. While the FDA has basically declared war on trans fats, store-bought frosting still contains a not-so-healthy dose of the stuff. How bad can trans fats be' Researchers at Wake Forest University gave groups of monkeys two different diets; one group ate trans fats and the other ate unsaturated fats. The results: The group eating trans fats upped their body weight by 7.2 percent in six years and the other only gained 1.8 percent. Not only did the trans fats add new fat, it was also responsible for moving fat from other areas to the belly. Check for trans fat in other foods like pre-made baked goods, snack foods, and frozen pizzas.Diet sodaIt's easy to get fooled by the zero-calorie label, yet sodas made with sugar substitutes are believed by many to play a role in weight gain. A new study published this month found that people who drank diet soda gained almost three times the amount of abdominal fat over nine years as those who didn't drink the no-cal stuff. Sure, that study only looked at adults ages 65 and older, but consider this: Recent research from the Weizmann Institute of Science found that mice drinking water with artificial sweeteners (saccharin, aspartame and sucralose) became vulnerable to insulin resistance and glucose intolerance--two things known to lead to weight gain.More from DETAILS:Brad Pitt Is Back and Sexier Than EverThe Fastest Way to Get RippedEat Your Way to a Better Sex LifeThe 14 Healthiest Snack Foods to BuyCan You Guess the Age of These Celebrities Based On Their Hot Bodies'Shirtless Nick Jonas Explains How He Got His New Buff Body -- This feed and its contents are the property of The Huffington Post, and use is subject to our terms. It may be used for personal consumption, but may not be distributed on a website. Click here to read full news..