How to Read a Food Label: Focus on trans fat

By M. Molly McMahon, MD, FACE

Nutrition can play a critical role in your personal program to prevent medical problems. It can also improve many common medical conditions you might already be struggling with. Endocrinologists [en-doh-krih-NOL-uh-jists] have always had a strong interest in nutrition. Learning how to use nutrition facts labels while shopping at the grocery store is important. These labels are required by the Food and Drug Administration (FDA) on most food products and beverages. Recently, attention has focused on the importance of minimizing (and ultimately eliminating) trans fat, a component of foods that can lead to blood vessel problems. The FDA also recommends decreasing the amount of added sugar in the foods we eat, which is suspected to add to problems with managing our weight. So, let’s focus on how to get the most from reading the food label.

A copy of the nutrition facts label for a small bag of potato chips is shown on the right side of this page. As you can see, information provided on the top half provides facts about the potato chips, including serving size, calories, and nutrient information. The bottom part provides daily recommended values for 2,000- and 2,500-calorie diets. The label footnote recommends important nutrients, including fats, sodium, and fiber. However, there is no recommended daily amount listed for trans fat or sugar.

Trans fat gets a lot of attention because of its bad effects on health. Trans fats are used to make liquid vegetable oils more solid (like margarine). This keeps foods fresher longer, makes shelf-life longer, and leads to a less greasy feeling when eating. Trans fat is found in many products, including some shortenings and margarines, deep-fried foods, baked goods, and crackers. The bad thing about trans fats is what they do to blood fats. They can increase levels of LDL (unhealthy) cholesterol and decrease levels of HDL (healthy) cholesterol. Also, trans fat intake can increase markers of inflammation. This is a process by which your body responds to injury. Inflammation plays a key role in heart disease. Most doctors and scientists believe that trans fat is worse than saturated fat.

Food labels are confusing. A product label can say no trans fat if the amount of trans fat in one serving size of that item contains less than 0.5 grams of trans fat. It may seem like eating 0.4 grams of trans fat does not matter, yet that is not true. Many experts advise intake of trans fat that is less than 1% of your total daily calorie intake. So if you are following a 2,000-calorie diet, your intake of trans fat should be less than 2 grams a day or about 20 calories. Small amounts can add up quickly. So how can the food item packaging information help you know if any trans fat is present in that food item? You must read the ingredient list. Trans fat is present if the ingredient list includes the words “partially hydrogenated [hahy-DROJ-uh-neyt-ed]” oils. Try to eat less of or none of foods that contain these words on the ingredient list. Choosing fruits, vegetables, whole grains, and lean sources of protein (like meat and dairy products) will help you eat less or no trans fat trans fat (and saturated fat) and will also offer many other health benefits.

Now let’s talk about the sugar content of foods. Recently, the American Heart Association suggested guidelines for upper limits of added sugar to our foods. What is added sugar? Added sugar is sugar added during processing, preparation, or at the table. By contrast, natural sugar is part of fruits, vegetables, and milk products. Unfortunately, nutrition facts labels do not detail the difference between added or naturally occurring sugars. High intake of sugar increases levels of triglycerides [try-GLIS-uh-rides] and decreases levels of HDL cholesterol. High intake is associated with diabetes and high blood pressure but does not cause diabetes or high blood pressure. And now we know that our preferences in taste can keep us from feeling full and make us eat more calories. High levels of stress can also make us eat more sugared foods.

The American Heart Association suggests that the average woman eat less than 100 (~6 teaspoons) calories from added sugar and men no more than 150 (~9 teaspoons) calories per day. One teaspoon of sugar has about 16 calories. Most Americans get more than 22 teaspoons of sugar per day!

Sugars are part of the make-up of fruit juice (choose 100% fruit juice when available or better yet, a piece of fruit), sweetened beverages, many sports drinks, desserts, breads, and sugared cereal. So it pays to keep your intake of sugar-sweetened drinks, sugared cereals, sugared dried fruits, and other sugary foods low. It can be fun to read labels for hidden sources of sugar, like some salad dressings, barbecue sauces, and fruit breads. Remember that natural sugars are present in fruits and vegetables, so not all sugar listed on the nutrition facts label is something to avoid in your diet. For example, fructose is a form of sugar found in fruits, honey, and vegetables. Lactose is a form of sugar found in dairy products.

Just think that a 20-ounce soda contains about 17 teaspoons of sugar! High intake of sugar-sweetened beverages by children is associated with weight gain, so try to have your children drink more water and less juice and sweetened beverages. Many beverage companies are now offering smaller sizes of sugar-sweetened drinks. Also, sugar-sweetened soda contains high-fructose corn syrup. High-fructose corn syrup has adverse effects on blood fats like triglyceride levels, and it adversely affects where fat is deposited in the body. Once again, eating a diet rich in fruits, vegetables, whole grains, and lean sources of protein is great for your health while limiting your intake of added sugar.

Summary Points:

  • Remember, there are health risks from eating trans fat and high amounts of added sugars.
  • Food item ingredient lists that include partially hydrogenated oil lets you know that trans fat is present in that food item even if the nutrition facts label states that no trans fat is present. Begin to read ingredient lists looking for sources of added sugars.
  • Eating a diet rich in fruits, vegetables, whole grains, legumes, and lean protein is great for your health, is tasty, and will limit your intake of trans fat and added sugar.

Dr. M. Molly McMahon is a consultant in the Division of Endocrinology, Diabetes, Metabolism, and Nutrition at Mayo Clinic in Rochester, MN. She is Professor of Medicine at Mayo Medical School. Dr. McMahon serves as the Practice Chair for Nutrition and the medical director of the clinical dietitians and the Nutrition Support Service allied health members. She also has a focus on wellness and healthy nutrition on campus and serves on the Wellness Executive Committee at Mayo Clinic.