Eliminating trans fats represents the latest in the fight against heart disease, but it’s only one part in addressing the issue. People still need to monitor their eating habits and activity level, said Angie Makris, Ph.D., R.D., an assistant professor at Temple University’s Center for Obesity Research and Education.

Also, contrary to popular misconceptions, reducing trans fats in the diet doesn’t necessarily translate into weight loss.

“In the past, much of the focus was on reducing the amount of fat consumed. Now, the focus is on the type of fat consumed,” Makris said. “Trans fats affect your cardiovascular health, not your caloric intake.”

As a nutritionist, Makris says the ultimate goal is good health. This can include losing weight to reduce risk factors for diseases such as heart disease and diabetes, eating nutritious foods, and increasing physical activity.

Trans fat has been shown to raise “bad” cholesterol (LDL-cholesterol) levels and lower “good"” (HDL-cholesterol) levels. Since the LDL/HDL ratio is a strong predictor of heart disease, these effects suggest that increased trans fat intake increases risk for heart disease.

Where do trans fats come from?

The process of hydrogenation during food manufacturing sometimes creates “trans fats.” The word hydrogenated refers to the process of changing oil from its natural liquid state to a more solid state by adding hydrogens to a fatty acid molecule. For example, margarine is a solid form of fat made from hydrogenated vegetable oil, Makris said.

Partially hydrogenated oils are attractive to food manufacturers because they reduce rancidity and consequently increase product shelf life and decrease refrigeration requirements.

The U.S. Food and Drug Administration mandated that trans fat content be listed on all packaged foods by January 2006. And then late last year, New York City's officials became the first to ban trans fat in restaurants by July.

Fast-food restaurants are taking notice, too. McDonald's Corp. has selected a new trans-fat free oil for cooking, but has not said when the oil would be introduced in restaurants. Burger King Holdings Inc. says it has begun testing oils without trans fats with plans for a national rollout by late next year. Wendy's International Inc. has introduced a zero-trans fat oil.

Makris advises following the FDA’s recommendations when it comes to fat intake:

• Replace saturated and trans fats with mono- and polyunsaturated fats, which do not raise “bad” cholesterol levels and have health benefits when eaten in moderation. Sources of monounsaturated fats include olive and canola oils. Sources of polyunsaturated fats include soybean, corn and sunflower oils, and foods like nuts.
• Eat fish. Most fish are lower in saturated fat than meat. Some fish, such as mackerel, sardines and salmon, contain omega-3 fatty acids that are being studied to determine if they offer protection against heart disease.
• Limit foods high in cholesterol like egg yolks and full-fat dairy products like whole milk.
  
  

Makris said she expects the issue of trans fats to stay in the news as more cities seek to ban their use and the FDA continues to modify its food labeling procedures.

Currently, trans fat levels of less than 0.5 grams per 14-gram serving can be labeled as 0 grams of trans fat; therefore, some products containing partially hydrogenated fat and claiming that they do not contain any trans fat, may indeed have small amounts of trans fat, according to FDA regulations.

The FDA plans to develop consumer education materials about trans fat and make improvements to the nutrition label in order to enhance consumers’ understanding about trans fat and nutrient content claims, Makris said.

“It’s a step in the right direction, but there’s a lot more to [good health] than trans fats,” Makris said.

Angie Makris has been answering questions on a forum about trans fats featured on Philly.com. She is also serving as the weight loss expert on Prevention.com. She is guiding readers through an 8-week program to lose weight and answering their questions in an online forum. Her research currently focuses on the effects of various dietary approaches such as the low carbohydrate, high protein, and glycemic index diets on satiety, eating behavior and weight loss.