- 26 October 2009
Fat. What comes to mind when you hear the word ‘fat’? For many, it sounds like a bad word. You don't want it in your body, and you don't want it in your food. Or maybe you do. Now doctors and nutritionists mention ‘good fat&’ and ‘bad fat’. What's the difference? What do I need?
Types of fats
There are four types of fats in our diet: saturated, trans, polyunsaturated, and monounsaturated. Most foods contain a mixture of these different fats. Interestingly, our body can produce most of the fats we need to function.
Saturated fats are found mostly in animal products- beef, pork, chicken, turkey, and whole-milk dairy products. Saturated fat is usually solid at room temperature. It's the greasy ‘chunks’ you may see on foods after they've cooled. Coconut, palm, and palm kernel oil are also high in saturated fat.
Trans fats are found in hydrogenated oils and are often seen in packaged goods like cookies, pastries, crackers, non-dairy creamers, solid vegetable shortening, and stick margarine (solidified vegetable oil). Trans fat acts like saturated fat in our bodies. Many food companies (and cities!) have now eliminated trans fat from foods. The debate between butter versus margarine continues - we’ll talk about that later in this article.
Polyunsaturated fats are usually liquid at room temperature. Two types of polyunsaturated fats are considered ‘essential fats’, meaning we have to consume foods containing these fats because our body cannot make them. These fats are called Omega-6 and Omega-3 fatty acids. Vegetable oils including corn, safflower, sunflower, and soybean oil contain mainly Omega-6 fatty acids. Nuts and seeds are also high in this type of fat.
Omega-3 fatty acids
Monounsaturated fats are also liquid at room temperature. Olive oil, olives, canola oil, peanuts, avocado, nuts and seeds are all high in monounsaturated fat.
What’s a good fat? What’s a bad fat?
When talking about ‘good’ vs ‘bad’ fat, we are considering the effects that a fat has on heart health. Studies have shown that certain types of fat effect blood cholesterol. Cholesterol is a fat-like substance that our body produces in the liver that is used to form cell membranes, some hormones, and other vital substances. Cholesterol is only found in animals and animal products. There are two main types of cholesterol in our body: HDL (think ‘healthy’) and LDL (think ‘lousy’). Together, they add up to ‘total’ cholesterol. Eating foods high in saturated fat and cholesterol can raise our ‘lousy’ and ‘total’ blood cholesterol. High blood cholesterol has been linked to higher risk of heart disease and stroke. Trans fats have the same effect on our blood cholesterol- it raises the ‘lousy’ and ‘total’, but also lowers our ‘healthy’ cholesterol. A double whammy! Polyunsaturated fats found mostly in plant foods lower ‘lousy’ and ‘total’ cholesterol, while monounsaturated fats do that AND increase our ‘healthy’ cholesterol. HDL is considered ‘healthy’ because it actually carries the bad cholesterol out of our bodies, lowering our risk of heart disease.
Butter vs Margarine
Butter is high in cholesterol and saturated fat (7 grams of saturated fat per tablespoon or ‘pat’!), which raises lousy and total cholesterol. Stick margarine is high in trans fat, which raises lousy and lowers healthy cholesterol. So which do you pick? Luckily, food companies have changed how they make margarine so that they have virtually no trans fat. They are typically found in tubs or sprays rather than sticks. Check nutrition labels and select the ones with the least trans fat and you will have the healthier alternative to butter.
Why do I need fat in my diet?
With all this talk of cholesterol and heart disease, you might be thinking, “Why even eat fat?” Dietary fat is vital for many reasons. First, fats can carry essential vitamins we need (called ‘fat-soluble’ vitamins) into our body. These vitamins are A, D, E, and K. We also discussed the two ‘essential fatty acids’- omega-6 and omega-3 earlier. Fats also carry the flavors of food, making them satisfying and giving our bodies a sense of fullness.
How much fat should be in my diet?
It depends on how many calories you take in daily. The recommendation is that fat provide no more than 35% of your total calories. Saturated fat should be less than 7% and trans fat less than 1%. Your total calorie needs are individual and are based on your gender, activity level, height, and weight. For example:if your total calorie intake is: then fat should be less than: 1,500 58 grams total, 11 g saturated, 1.5 g trans 1,800 70 grams, 13 g saturated, 2 g trans 2,000 78 grams, 15 g saturated, 2 g trans 2,200 85 grams, 17 g saturated, 2.5 g trans 2,500 97 grams 19 g saturated, 2.5 g trans
Limit cholesterol to less than 200 mg (milligrams) per day.
The Institute of Medicine established an adequate intake for omega-3 is 1.6 grams per day for men, and 1.1 grams per day for women. This can be obtained by eating a variety of fish at least twice a week. Fatty fish contain more omega-3's than other fishes. Including flax seed oil, canola oil, and soybean oil or tofu, as well as leafy green vegetables and walnuts will also meet your needs. Supplements are also available- be sure not to take more than 3 grams per day without your doctor's approval. Most diets include ample amounts of omega-6 fatty acids. The goal is to increase the ratio of omega-3's to omega-6 for optimal health, many experts say.
Is ‘fat free’ better?
If you are trying to reduce your fat intake, then yes. If you are trying to lose weight, then maybe not. Some studies have shown that the more fat a person eats, the more calories they eat, causing weight gain. However, choosing fat free or low fat alternatives of sweets like low fat ice cream, low fat frozen yogurt, low fat cookies, etc, do not necessarily mean less calories. People tend to eat more of a low fat or fat free item than they would the full fat version, thereby increasing overall calorie intake, causing weight gain. Often, the fat is replaced by extra sugar (calories) to substitute the flavor that fat provides.
Choosing low fat or nonfat dairy products and lean meats (lean beef, skinless chicken and turkey) are healthy ways to reduce your total fat and cholesterol intake. They also contain fewer fat calories, which may promote weight loss.
What do I look for on a food label?
You may notice food labels claim a vegetable or fruit is ‘cholesterol free!’- well, it has been since the beginning of time! Remember, only animals (including people!) make cholesterol.
When reading food labels, be sure to look at:
- Serving size: Will you be eating one serving?
- Servings per container: Will you be eating the whole thing?
- Calories: Here's where the ‘low fat’ or ‘fat free’ may make a difference… or not.
- Total Fat: less than 5% of the % Daily Value is ideal.
- Saturated Fat and Trans Fat: remember that less is more- compare food labels of similar items and select foods with the least amount.
A healthy diet consists of a variety of foods. Balance is the key. Understanding the difference between ‘good’ and ‘bad’ fats will help you make more informed choices and help protect your hard-working heart and keep you dancing!