Thursday, April 30, 2009

Deconstructing Fats: The Good, The Bad and The Ugly

LDL, HDL, bad and good cholesterol, saturated and unsaturated fats... what does it all mean?

There's so much information floating out there about "good" and "bad" fats, and that information seems to constantly change depending on the day and the source. It can be hard to determine right from wrong. Which fats are acceptable to eat, which fats are necessary for heart and whole body health, and which ones will make us, well, fat?

Here's a basic breakdown for you.


LDL- low density lipoproteins = BAD cholesterol (sticks to arterial walls)
HDL- high density lipoproteins = GOOD cholesterol (doesn't stick to arterial walls)

Saturated Fats- come from animal products and palm and coconut oils (non-essential fats)
Unsaturated Fats- come from plants and are essential to the body

Polyunsaturated and monounsaturated fats (the good fats) come from whole food sources like nuts, seeds, avocadoes and high-quality oils (olive and vegetable).

These good fats are thought to lower LDL levels. (LDL is the type of cholesterol that clings to the walls of blood vessels, eventually building up and causing cardiac problems.) They are essential to the healthy functioning of your body. You could not live without these fats, in limited amounts.

Saturated fats (the bad fats) are found mostly in foods that come from animals, such as meat and dairy products, and also in palm and coconut oils. Saturated fats are not essential to your body and can be easily cut out of your diet.

Your total dietary intake of all fats should be limited to 35% of your total caloric intake. Of this, the majority of fat should be of the good variety. Of course, that doesn't mean you should deprive yourself of your favorite foods or stop eating meat entirely (unless you are vegan). Meat and animal products can be healthy for other reasons, and everything in moderation!

One easy way to spot the good and the bad? Saturated fats are solid at room temperature; unsaturated fats are liquid.

In defense of fats

Fat is the richest energy source the body has. (Although it is not the most readily converted to usable energy.)

Fat is essential for our cell membranes, brain function, the health of our reproductive and immune systems, and for healthy skin.

Fat insulates our nerve cells, keeps us warm, balances our hormones, keeps skin healthy and arteries supple, lubricates joints, and is a vital component in every cell in our bodies. We would not be human, or even mammalian, without it.

However, if you don't burn them off, the body likes to store calories from fat as fat. Same with processed carbohydrates. Veggies and fruits, on the other hand, tend to be burned off first.

Creating change: There are 3,500 calories in a pound of fat. So, to lose a pound a week, you need to create a 500-calorie-a-day deficit. Your body will then burn those extra calories from your fat stores. This is a manageable amount of calories to cut out of your diet. Small changes can make the difference. An hour workout can burn up to 900 calories.

Start by cutting out empty calories: foods and beverages that have calories but no nutritional benefit. The calories from these foods tax your digestive system and contribute to unwanted fat storage. You can make a big difference by eating less processed foods and no sweetened beverages and for some, limiting alcohol intake.

Lark Miller
phone: 415.250.5236