New dietary guidelines

(CNN) -- It seems the most popular questions people ask me relate to diets: How much fat is too much? What about sugars and how about that Atkins diet?

Well, it is very confusing and may have become even more convoluted with a recent report by the Institute of Medicine.

Earlier guidelines on nutrient intakes called for a diet comprised of 30 percent or less of fat. According to the new report, the recommended intake now ranges between 20 percent and 35 percent.

While it did not suddenly become all right to eat more fat, it appears the government realizes that more freedom is probably acceptable.

Adults should get between 10 percent and 35 percent of their calories from protein and 45 percent to 65 percent from carbohydrates, according to the institute.

Click here to read the nuts and bolts of the new guidelines.

When talking about fat, it's important to remember that not all fat is bad. The saturated fats are typically the bad ones found in animal fat and butter. Unsaturated fats, such as those found in canola oil and soybeans, are better and can in fact lower your LDL, also known as the "bad" type of cholesterol.

The information is constantly changing so it's important to keep up by reading "The Pulse," my weekly column on the week's top health and medical news.

Here are other stories making headlines this week.

McDonald's cuts the fat

McDonald's Corp. announced it is changing the cooking oil used for its french fries and other fried foods.

The new oil will contain less saturated fat and trans-fatty acids -- which significantly contribute to high cholesterol and heart disease -- and more of the good polyunsaturated fat.

While some praise McDonald's efforts to reduce artery-clogging fat, others say eaters should beware, because there is still plenty of bad fat and calories in an order of fries.

Click here for more information on the fast-food giant's nutrition initiative.

Teen girls need more exercise

Physical activity in girls plunges dramatically during adolescence, according to a new study that followed almost 24,000 girls from age 10 to 19.

The drop is worse for African-American teens than their white counterparts.

Researchers found that by the age of 18 or 19, the majority of girls engaged in almost no regular physical activity outside of what's required at school.

The study showed that obesity doubled even though no significant increase in calorie consumption was reported.

In another study, researchers found that postmenopausal women can walk themselves to good health.

The study of more than 73,000 older women confirmed that walking is as good as vigorous exercise in preventing cardiovascular disease in women of all races and body types.

Being a couch potato, on the other hand, was associated with an increased risk of heart trouble.

Click here for more information on the studies and to find out which factors affect girls' decline in physical activity.