Privacy Policy. Fat is a type of nutrient, and just like protein and carbohydrates, your body needs some fat for energy, to absorb vitamins, and to protect your heart and brain health. But now we know that not all fat is the same. In fact, healthy fats play a huge role in helping you manage your moods, stay on top of your mental game, fight fatigue, and even control your weight.
By understanding the difference between good and bad fats and how to include more healthy fat in your diet, you can improve how well you think and feel, boost your energy, and even trim your waistline. Dietary fat plays a major role in your cholesterol levels. Cholesterol is a fatty, wax-like substance that your body needs to function properly. But when you get too much of it, it can have a negative impact on your health.
As with dietary fat, there are good and bad types of cholesterol. Rather than the amount of cholesterol you eat, the biggest influence on your cholesterol levels is the type of fats you consume. These fats can help to:. Adding more of these healthy fats to your diet may also help to make you feel more satisfied after a meal, reducing hunger and thus promoting weight loss.
Trans fat. Artificial trans fats can also create inflammation, which is linked to heart disease, stroke, and other chronic conditions and contributes to insulin resistance, which increases your risk of developing Type 2 diabetes. In the U. However, products made before the FDA ban may still be available for sale. If your country still allows the use of artificial trans fats, remember that no amount is considered safe, so aim to eliminate it from your diet.
Saturated fat. For decades, doctors, nutritionists, and health authorities have told us that a diet high in saturated fats raises blood cholesterol and increases the risk of heart disease and stroke. However, recent studies have made headlines by casting doubt on those claims, concluding that people who eat lots of saturated fat do not experience more cardiovascular disease than those who eat less.
For example, swapping animal fats for vegetable oils—such as replacing butter with olive oil—can help lower your cholesterol and reduce your risk for disease.
Limiting your intake of saturated fat can still help improve your health—as long as you take care to replace it with good fat rather than refined carbs. Omega-3 fatty acids are a type of polyunsaturated fat and are especially beneficial to your health.
For the rest of us, the AHA recommends eating at least two 3. People in the UK tend to eat a lot more saturated fats than trans fats. This means that when you're looking at the amount of fat in your diet, it's more important to focus on reducing the amount of saturated fats.
If you want to reduce your risk of heart disease, it's best to reduce your overall fat intake and swap saturated fats for unsaturated fats. There's good evidence that replacing saturated fats with some unsaturated fats can help to lower your cholesterol level.
Mostly found in oils from plants and fish, unsaturated fats can be either monounsaturated or polyunsaturated. Monounsaturated fats help protect your heart by maintaining levels of "good" HDL cholesterol while reducing levels of "bad" LDL cholesterol in your blood.
Polyunsaturated fats can also help lower the level of "bad" LDL cholesterol in your blood. Some types of omega-3 and omega-6 fats cannot be made by your body, which means it's essential to include small amounts of them in your diet.
Most people get enough omega-6 in their diet, but it's recommended to have more omega-3 by eating at least 2 portions of fish each week, with 1 portion being an oily fish. Vegetable sources of omega-3 fats are not thought to have the same benefits on heart health as those found in fish. Find out more about healthy eating as a vegetarian.
The nutrition labels on food packaging can help you cut down on total fat and saturated fat also listed as "saturates", or "sat fat". Nutrition information can be presented in different ways on the front and back of packaging. As this research in the New England Journal of Medicine shows , for every 2 percent of calorie intake that comes from trans fats, a person's heart disease risk increases by an incredible 23 percent.
That explains why the Food and Drug Administration has been working to phase trans fat out of the food supply and doctors recommend that people keep their consumption of it as close to zero as possible. At this point, most scientists agree that unsaturated fat, relative to the other fat types, appears to be the least problematic for human health.
As Dariush Mozaffarian , an epidemiologist at Tufts University, describes in the journal Circulation , numerous studies have found that eating polyunsaturated fat the kind found in fish, sunflowers, and walnuts can decrease the amount of bad LDL cholesterol in the blood, raise the amount of good HDL cholesterol, and lower the risk of cardiovascular disease. Monounsaturated fats found in olive oil, avocados, and almonds have also shown similarly favorable effects on blood lipids and cardiovascular disease — they seem to decrease LDL cholesterol while maintaining HDL cholesterol.
Though there's a caveat here: Mozaffarian and other researchers caution that long-term studies on monounsaturated fats show mixed results on cardiovascular disease. So they say, "Some caution is needed. Unlike unsaturated fat, saturated fat has been shown to increase LDL cholesterol again, the bad kind , so some researchers have wondered whether eating a lot of this stuff must therefore increase the risk of cardiovascular disease.
Starting in the s and '60s, that hypothesis was backed up by observational studies that looked at people who ate different diets and found a link between a diet heavy in saturated fat and cardiovascular diseases. This research was the basis for dietary guidelines that have long recommended people cut their saturated fat intake to stave off their risk of this leading killer. More recent research, however, has suggested that the effects of saturated fat on health may not so clear-cut, says Tuft's Mozaffarian.
It's true that saturated fat appears to affect blood levels, but the question of whether this alone truly ends up altering a person's cardiovascular disease risk remains controversial. The BMJ analysis , published in March, finds lowering blood cholesterol by lowering the intake of saturated fats doesn't in fact translate to improved survival — but as noted above, the study had some serious limitations.
There are two key reasons for the controversy. First, studying diet and its impact on health is really, really difficult. People don't consume macronutrients like fat. They consume food , which typically contains fats but also lots of other ingredients, and their diets change over time. Maybe people who eat foods rich in saturated fats have poorer diets generally, and those who don't have lots of other healthy behaviors. This helps explain some of the mixed findings on questions about fat, such as these recent reviews of the observational research , which concluded that the evidence that saturated fat alone had a bad effect on the heart is weak and unconvincing.
Second, scientists have been finding that what you're eating besides saturated fat can be just as important for your health more on this below.
Many of the experimental studies on saturated fat asked people to swap saturated fat out of their diet for some other type of macronutrient. It turns out that people ended up with different health outcomes depending on what else they ate, leaving researchers to wonder whether fat or diet generally was the key variable here. This Cochrane Review of long-term randomized controlled trials on saturated fat, for example, found that reducing one's saturated fat intake can reduce the risk of cardiovascular disease including heart disease and stroke , but it really depends on what you replace that food with.
People who replaced saturated fat with unsaturated fat got the most benefit. So researchers generally don't disagree about the fact the unsaturated fat seems to be better than saturated fat for health. But they do disagree abut what to do with that information. Some, like Harvard's Frank Hu , continue to advocate saturated fat reduction as a way to better health.
But other researchers say the focus on fats is confusing and outdated. The panic over saturated fats in the past pushed many people to foods higher in sugar, which we now know is just as bad.
So it's probably helpful to think of various fats on a spectrum. Trans fats appear to be the worst for health, unsaturated fats the best, and saturated fats somewhere in between. Even with the uncertainty, most doctors will suggest that you should replace saturated fats with unsaturated fats whenever possible.
And there is a lot of good research to back this up. Numerous s tudies have found that when people swap out their saturated fats for unsaturated fats especially polyunsaturated fats, like those found in fish they reduce their risk of coronary heart disease. The new US dietary guidelines also recommend replacing saturated fat with polyunsaturated fat to reduce the risk of cardiovascular disease and mortality.
This doesn't justify any "low-fat" diet, however. Studies have also found that when people swap out saturated fats for more refined carbohydrates, their health doesn't improve. So it's probably a good idea to replace a cheeseburger with fish or lentils.
It's not necessarily a good idea to replace an egg with a low-fat muffin or bagel. It's a common misconception that eating fat makes you fat. Garton adds that some people might benefit from eating even less saturated fat than the standard recommendation — specifically those who have other risk factors for heart disease. That's because it is only one of several dietary factors affecting heart disease risk, all of which are interrelated. A number of international organisations draw on scientific evidence to recommend reducing saturated fat and replacing it with unsaturated fat.
Scientific research backs up this advice. So did replacing saturated fats with whole grain carbohydrates such as brown rice and wholemeal bread. However, when sugar and refined starches such as white flour replaced saturated fat, the risk of having a heart attack actually increased. This could actually be worse than making no reduction to saturated fat at all. For example, stearic acid, which makes up approximately half of the saturated fats in dark chocolate, does not raise blood cholesterol.
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