Monounsaturated fats do not undergo modification, and, when substituted for saturated fats, can help lower LDL cholesterol levels. Replacing saturated fats with monounsaturated fats — for example, using olive oil instead of butter — is one way to improve a wayward lipid profile, as long as you aren’t just adding monounsaturated fats and forgetting to cut back on the saturated fats.

Other diet changes that will help lower cholesterol include eating more fiber, such as that found in oat bran, and increasing your consumption of plant stanols and sterols, which are found in a number of food products. Plant stanol margarines such as Benecol and Take Control are worth trying, since regular use can help lower LDL cholesterol levels.

Research shows that genetic and physiological differences influence how dietary fat affects cholesterol levels. To maximize the benefits of modifying fat intake to lower cholesterol, you should:

1. Determine whether diet changes work for you. Say you decide to try a lower-fat, lower-cholesterol diet for three to six months, but at the end of the trial period, a blood test shows that your cholesterol levels haven’t budged. You may belong to the nonresponder group and need a different kind of diet, or medication, to control your cholesterol.

2. One size doesn’t fit all. When a friend or relative tells you how much his or her cholesterol level dropped after trying a particular diet, you may be tempted to try it too. But if after a few months you discover that the diet has no effect, remember, there isn’t a one-size-fits-all recommendation for fat or cholesterol consumption. You may have to try several different diet and exercise approaches to find one that works for you.