Diabetes & Dietary Fats

Everyone needs some fat in their diet, but saturated fats, cholesterol, and trans fats are unhealthy and increase your risk of a heart attack or stroke. A type of polyunsaturated fat called omega-3 protects the heart, however.

Saturated fats and cholesterol

Eating saturated fats and cholesterol increases blood levels of LDL cholesterol and insulin, which contribute to coronary heart disease (CHD). Because people with diabetes are at especially high risk for heart disease, the American Diabetes Association recommends a diet that includes less than 10% of calories from saturated fats and less than 300 mg a day of cholesterol.

If your LDL cholesterol is above 100 mg/dL, your doctor may suggest that you lower your saturated fat intake to less than 7 percent and your dietary cholesterol to less than 200 mg a day. The American Heart Association recommends that you keep your saturated fat intake below 7 percent of total calories regardless of your LDL cholesterol level.

Rather than calculating the percentage of calories from saturated fat and counting milligrams of cholesterol, it may be easier to simply cut back on foods containing these fats. Foods high in saturated fat include red meats, dark-meat poultry, poultry skin, whole-milk dairy products, and products made with hydrogenated oils or coconut, palm, or palm kernel oils. Cholesterol is found only in animal foods and is particularly plentiful in egg yolks, organ meats, shrimp, crab, and lobster.

Another way to reduce saturated fats and cholesterol in your diet is to replace them with more healthful fats. Consuming monounsaturated fat—which is plentiful in olive and canola oils and inavocados and some nuts—lowers total blood cholesterol levels without reducing HDL cholesterol. It may also help prevent the accumulation of LDL in the walls of large arteries (one of the first steps in the development of atherosclerosis, or hardening of the arteries). Polyunsaturated fats, found in vegetable oils like safflower, corn, sunflower, and soybean oils, also help to lower total cholesterol levels but may reduce HDL cholesterol. Even though monounsaturated and polyunsaturated fats have beneficial effects, they're still high in calories, so intake must be limited.

Trans fats

Another unhealthy fat is trans fat. It is found in hydrogenated and partially hydrogenated oils and in margarines. Trans fats raise blood levels of LDL cholesterol and lower levels of HDL cholesterol. The American Heart Association recommends that trans fat intake make up no more than 1% of the calories you eat. So if you typically eat 1,500 calories a day, you should consume no more than 1.5 g of trans fat a day. All food labels now include the amount of trans fat (in grams) per serving.

Omega-3 fat

This polyunsaturated fat has heart-protective benefits, reducing blood levels of triglycerides and preventing life-threatening abnormal heart rhythms. Fatty fish such as salmon, mackerel, trout, and herring are the best sources of omega-3 fat. The American Diabetes Association recommends that people with diabetes eat two to three servings of fish each week to reap the heart benefits of omega-3 fat. If you're concerned about mercury contamination, eat a variety of fish and limit your consumption of tuna, swordfish, king mackerel, shark, and tilefish.

Publication Review By: Written by: Christopher D. Saudek, M.D.; Simeon Margolis, M.D., Ph.D.

Published: 20 Apr 2009

Last Modified: 11 Sep 2015