Lower fat intake is good for your heart and your waistline
Avoiding fat on your plate can help you avoid fat on your body.
And if that isn't motivation enough, a recent study showed that eating just one meal high in saturated fat can affect the body's ability to protect itself against some of the underlying causes of heart disease and stroke.
Fourteen participants from a study in the Journal of the American College of Cardiology were given a meal high in saturated fat (about 61 grams) and on a separate occasion, a meal high in polyunsaturated fat but the same number of calories.
The high saturated fat meal hampered the ability of "good" cholesterol — high-density lipoprotein (HDL) — to do its job. That job is to protect the inner lining of the arteries from inflammatory agents that promote plaque, which clogs the vessels.
After three hours, the meal high in saturated fat had reduced the ability of the arteries to expand to increase blood flow. The polyunsaturated fat meal had no measurable effect.
The researchers also found that, when they sampled the study participants' blood six hours after eating, the good (HDL) cholesterol's anti-inflammatory properties had decreased after the saturated fat meal but improved after the polyunsaturated fat meal.
"In our studies, we found similar effects," says Christy C. Tangney, PhD, an associate professor in the Department of Clinical Nutrition at Rush University and an expert on the effects of diet and nutrition on heart health. "We also found that high saturated fats affect how easily the blood itself flows — its viscosity. High saturated fat meals make the blood thicker and slower.
"Many groups have shown that there is a dramatic reduction in the relaxation capability of the arteries attributable to the ingestion of meals enriched in saturated fats," Tangney continues.
"This type of meal markedly elevates triglycerides, which affects the bloods capacity to flow. That's why when you are being tested for lipids or specifically your LDL cholesterol, your doctor asks you not to eat a minimum of eight hours before cholesterol and lipid tests, so that the effect of the previous meal doesn't cloud the picture."
Applying the research
Tangney recommends avoiding saturated fat as much as possible. "It's a question of balance, but you don't need saturated fat in your diet at all," says Tangney.
"While your body needs some fat, it really doesn't need saturated fat, which can be made in our bodies from carbohydrates." Tangney suggests that you be as informed as possible about what you're eating.
"We really need to ask for more nutrition information (at least total calories and fat content) on menus at restaurants, so that people can make better choices. I think most people would think twice when they saw the fat content of the average fast food meal."
Total fat intake should be no more than 30 to 35 percent of your daily calorie intake. And you should consume even less saturated fat, the main dietary cause of high blood cholesterol, according to the American Heart Association (AHA). The AHA recommends limiting saturated fat intake to just 7 percent of your total daily calories.
Of course, you don't want to get your daily dose of fat in one sitting, nor from only one food so you'll want to mix up your choices throughout the day.
"Ultimately, your daily calorie intake will depend on your energy needs," says Tangney. "This is related to such things as how physically active you are, your body composition or percentage of lean body tissue to fat and whether you're at an age where your body's still developing."
Saturated fats can be readily found in meat, poultry and other animal products like butter and cream. Some plant sources of saturated fat include cocoa butter, coconut and palm oils.
Most people tend to get far too much fat in their diet, which contributes to health problems such as obesity, high blood cholesterol and heart disease. While coconut and palm oils contain no cholesterol, they are high in saturated fat and should be avoided.