Over the years, fats have developed a bad reputation. While fats are an important component of a healthy diet, consuming too many fats can lead to various health problems. It is not only the amount of fat you eat to which you have to pay attention, but also the types of fat you choose.
Types of Fat
Fat is categorized into three major types, unsaturated, saturated and trans, based on its chemical structure. Unsaturated fats, often referred to as good fats, contain carbon atoms that are not bonded to, or saturated with, hydrogen atoms. Unsaturated fats are in nuts, seeds, vegetable oils, fish and avocados. Saturated fats are a natural type of fat, mainly found in foods from animal sources like meat, poultry, eggs, butter and milk, that contain carbon atoms saturated with hydrogen atoms. Most trans fats are made during food processing. These synthetic fats form when unsaturated fats are saturated with hydrogen atoms during a process called partial hydrogenation. Mass-produced foods, like crackers and cookies, commercially baked items and margarines often contain trans fats.
Heart Disease
Saturated fats and trans fats directly raise the levels of cholesterol in your blood. When you eat too much of these types of fats, the amount of cholesterol in your blood gets so high that the cholesterol has nowhere to go but on the inner walls of your arteries. When cholesterol accumulates on your arterial walls, it hardens and thickens the arteries, making it more difficult for blood to flow through them. As a result, your heart pumps harder to compensate. This extra stress on the heart can lead to weakened heart muscles, and eventually, coronary heart disease.
Weight Gain
Fat is the most energy-dense nutrient, providing you with 9 calories per 1 g. Because of this, a diet high in fat can cause calories to add up quickly. If you exceed your calorie needs regularly, it can result in weight gain, eventually leading to obesity. Obesity is a major risk factor for insulin resistance and Type 2 diabetes.
Considerations
When discussing the negative effects of fat, it is also important to note the health benefits that come from choosing the right types of fat. A higher intake of polyunsaturated and monounsaturated fats has been linked to lower incidences of heart disease. Women who replaced 80 calories of carbohydrates with 80 calories of unsaturated fats every day reduced their risk of heart disease by 30 to 40 percent, according to a review on the Nurses' Health Study, which was published in the "Journal of the American College of Nutrition" in February 2001.
Dietary fat also helps you feel full. When you include some healthy fat at each meal, you feel full faster, which may help prevent overeating, lowering the risk of weight gain.
References
- MayoClinic.com; Dietary Fats: Know Which Types to Choose; February 2011
- Harvard School of Public Health: Fats and Cholesterol: Out With the Bad, In With the Good
- "Journal of the American College of Nutrition"; Types of Dietary Fat and Risk of Coronary Heart Disease: A Critical Review; Frank Hu, et al.; February 2001
