On common belief， unsaturated fats， have a protective effect on our health， saturated fat has a bad reputation. Many see saturated fat as nothing but artery-clogging， obesity-causing poison. But there is mounting evidence that eating some saturated fats may actually be good for the heart and help you lose weight. A systematic review funded by the British Heart Foundation caused quite a stir.

Scientists from Oxford， Cambridge， Harvard examined the links between eating saturated fats and heart disease. When they looked at blood results， they found that higher levels of some saturated fats， in particular a type of saturated fat you get in milk and dairy products called margaric acid， were associated with a lower risk of heart disease.

In another study funded by the US National Institutes of Health， researchers found eating fewer carbohydrates and more fat （both saturated and unsaturated）， with the exception of trans fat， can reduce the risk of heart disease.

Diets low in carbohydrates and higher in fat and protein have been commonly used for weight loss. But these diets have been criticized for causing people to lose weight in the form of water instead of body fat.

Eating more saturated fat does lead to higher cholesterol levels， but the US study has shown saturated fat also raises levels of so-called good HDL cholesterol， which removes the bad LDL cholesterol that can accumulate on arterial walls.

Besides， there are two kinds of LDL particles： small， dense ones and large， fluffy ones. The large ones seem to be mostly harmless - and it's the levels of those large particles that fat intake raises.

The type of the small sticky particles is generally controlled by carbohydrate consumption， the website of a health and fitness media startup. So the best way to cut out harmful types of cholesterol and reduce the risk of heart disease would be to follow a diet thats low in carbs， rather than fat.

This research and new findings on fat don't mean every source of saturated fat is healthy. A study from the Harvard School found that after analyzing the diets of 1.2 million people， there was no association between eating red meat and heart disease， but there was for those who ate a lot of processed meat. So， if we're going to get sick from eating meat or saturated fat， it'll be by getting it from a crappy source.

1.What is the common belief about saturated fats and unsaturated fats？ ____.

A. Saturated fats are beneficial to health

B. Unsaturated fats can trigger heart attack

C. Saturated can cause obesity

D. Unsaturated fats may cause clotted artery

2. Why have weight loss diets low in carbo-hydrates and higher in fat and protein been criticized ？ _____.

A. They are believed to cause artery clogging

B. They are believed to cause people to lose weight to excess

C. They are believed to cause malnutrition

D. They are believed to cause people to lose weight in the form of water instead of body fat

3. What does the US study show？ ____.

A. Saturated fat can cause bad LDL cholesterol to accumulate on arterial walls

B. Saturated fat can raise levels of good HDL cholesterol， which removes the bad LDL cholesterol

C. Eating too much red meat may cause heart disease

D. The best way to cut out harmful types of cholesterol is to follow a diet that's low in carbohydrates but high fat.