I’m speaking of trans fats. Trans fats are mostly manufactured. Small amounts do occur naturally in some animal products (meat and dairy), but the vast majority occurs in processed foods. Trans fats are created when liquid vegetable oils (such as safflower and sunflower) are processed by hydrogenation into solid fats (margarine and shortening). This means that food companies add hydrogen to the liquid oil. Food manufacturers prefer adding hydrogen to liquid oil to extend shelf life of their products. They are useful in fast food chains because trans fats withstand higher heating temperatures used in fryers.
Most types of fats occur naturally and are required for a healthy diet. The FDA recommends up to 30% of one’s calories be composed of fats (although other nutritional sources recommend smaller percentages, as little as 15%, of fats). But not all fats are the same. Monounsaturated fats are healthiest for one’s heart. They can be found in olive, canola, sunflower, safflower, avocado, almond, peanut, corn, sesame, rice bran, and soybean oils. Saturated fats are not as heart healthy and are found in animal products. The oils that provide saturated fats include coconut and palm oils.
Sunflower oil in its natural liquid form represents the healthier oil option. It’s when it is hydrogenated that it is trouble. The research is unequivocal: trans fats are not good for your health. Although as a monounsaturated fat, sunflower oil can reduce your risk for heart disease, once it is hydrogenated into trans fat it increases coronary artery disease. Trans fats increase the risk for heart disease, stroke, and type 2 diabetes. Trans fats increase LDL (bad cholesterol) and reduce HDL (the good kind). They are even less healthy than saturated fats which increase LDL but don’t have a negative effect on HDL.
Current guidelines recommend limiting trans fats to less than 1% of one’s daily caloric intake (about 2 grams in a 2000 calorie diet). Unfortunately, a product can legally be labeled as having no trans fat if the product contains up to 0.5 gram of trans fat per serving. That means that even a cautious consumer may end up with trans fats in her diet. Eating four of such labeled products can result in one eating 2 grams of trans fat without realizing it.
So how does a health-minded consumer select foods that are unlikely to have trans fats? I recommend two methods of evaluating food for trans fats. First, know the kinds of foods that are likely to contain trans fats. They are likely in fried foods, baked goods, cookies, crackers, stick margarines, chips, and microwave popcorn. Avoiding processed foods such as these will limit the amount of trans fats in your diet. If you do want to consume a product from this list then look beyond the nutrition label. Remember that the nutrition label needs to list the percentage of trans fat but it could contain half a gram and still say 0% on the label. I recommend reading the ingredient list instead. Avoid products that list partially hydrogenated anything. Avoid products that list shortening in their ingredient list. In restaurants, avoid fried foods and pastries, pie crusts and biscuits. Opt for natural food sources rather than processed foods. Prepare meals and desserts in your own kitchen where you can control the contents. Just avoid trans fats completely to care for your health.
Oh, and the other two non-foods posing as foods in grocery stores and restaurants are easier to identify and to eliminate. They are: processed meats (anything cured, smoked, deli meats, jerky, hot dogs, sausages, etc) and sodas (full sugar and diet alike).