Consuming high levels of calories – regardless of the source – can lead to weight gain or being overweight. Consuming high levels of saturated or trans fats can also lead to heart disease and stroke. Health experts generally recommend replacing saturated fats and trans fats with monounsaturated fats and polyunsaturated fats – while still maintaining a nutritionally-adequate diet.
Monounsaturated fatty acids. This is a type of fat found in a variety of foods and oils. Studies show that eating foods rich in monounsaturated fatty acids improves blood cholesterol levels, which can decrease your risk of heart disease. Research also shows that these fatty acids may benefit insulin levels and blood sugar control, which can be especially helpful if you have type 2 diabetes.
Following a high monounsaturated fat diet can be beneficial for improving insulin sensitivity in both individuals who have, or do not have high blood sugar levels. One study found that following a high monounsaturated fat diet for three months managed to improve insulin sensitivity by up to nine percent (14). This was followed by another study which found participants who had metabolic syndrome and followed a high monounsaturated fat diet for twelve weeks had a significant reduction in insulin resistance (15).
One easy rule: You should always avoid trans fats—they’re listed on the nutrition label as “partially hydrogenated oils.” Most are artificial and raise your LDL cholesterol while lowering your HDL cholesterol (the good kind that helps keep blood vessels clear). According to the American Heart Association, trans fats increase your risk of developing heart disease and stroke, and are associated with a higher risk of type 2 diabetes.
You may wonder isn't fat bad for you, but your body needs some fat from food. It's a major source of energy. It helps you absorb some vitamins and minerals. Fat is needed to build cell membranes, the vital exterior of each cell, and the sheaths surrounding nerves. It is essential for blood clotting, muscle movement, and inflammation. For long-term health, some fats are better than others. Good fats include monounsaturated and polyunsaturated fats. Bad ones include industrial-made trans fats. Saturated fats fall somewhere in the middle.
SOURCES: WebMD Weight Loss Clinic Expert Column:"The Skinny on Fats." WebMD Weight Loss Clinic Feature: "Trans Fat Free Food: What's the Truth?" Alice H. Lichtenstein, DSc, Gershoff Professor of Nutrition Science and Policy, director and senior scientist, Cardiovascular Nutrition Laboratory, Jean Mayer USDA Human Nutrition Research Center on Aging, Tufts University. Robert Eckel, MD, past president, American Heart Association. Michael Jacobson, PhD, executive director, Center for Science in the Public Interest. Colleen Doyle, MS, RD, nutrition and physical activity director, American Cancer Society.
The guidance on saturated fat is a little more complicated. Old nutrition research said saturated fat was really bad for your cholesterol levels, but newer information suggests it has a more neutral effect. The topic is very touchy, and the USDA Dietary Guidelines and the American Heart Association still recommend limiting your intake and opting for monounsaturated and polyunsaturated fats instead. Many of the healthy foods below have some saturated fat in them, but it doesn’t make up the majority of the fat content and won’t negate the positive effects of the healthier fats.
Although for several decades the American Heart Association and other health organizations have advised people to reduce their saturated fat intake, studies have consistently failed to show a link between saturated fat and heart disease. Because of this, the role of natural saturated fats in a healthy diet is now being reconsidered. All in all, saturated fats appear to be neutral in their health effects.
Unfortunately, buying this healthy fat isn’t as easy as just grabbing the first bottle you see. Make sure to pick only extra virgin varieties of the oil, which means no chemicals are involved when the oil is refined. Unfortunately, many common brands have been shown to fail the standards for extra virgin olive oils, meaning it’s important to choose wisely.