Conventional wisdom on dietary fats has changed. Once, all fats were deemed unhealthy, and responsible for all manner of diseases, from cardiovascular disease to diabetes. But years of research have changed our thinking. We now start with the premise that all fats are not created equal—that there are good fats, bad fats, possibly-not-so-bad fats, and very bad fats. Let's take a closer look:

The Good: Unsaturated Fats

As oxymoronic as it sounds, there are actually good fats—the unsaturated kind that help fight the very diseases that consuming excess fat was said to cause. These unsaturated fats are divided into monounsaturated fats and polyunsaturated fats, and both types are thought to have beneficial effects on cholesterol levels.

Monounsaturated fats help lower LDL (bad) cholesterol while also boosting HDL (good) cholesterol.

Polyunsaturated fats are also thought to help lower total and bad cholesterol. But monounsaturated fats tend to be favored over polyunsaturated fats because some research suggests that polyunsaturated fats are less stable, and can reduce levels of good cholesterol as well as bad.

But let's not ignore polyunsaturated fats. These are often a good source of omega-3 fatty acids, found mostly in cold-water fish, nuts, oils and seeds, and also in dark leafy greens, flaxseed oils and some vegetable oils. One kind of omega-3 fatty acid is an "essential fatty acid," which cannot be manufactured by our bodies, so eating these foods is the only way to get them. Omega-3 fatty acids are thought to lower blood pressure, combat LDL (bad) cholesterol, fight inflammation and protect the brain and nervous system.

Heart-Healthy Walnuts

The Benefits of Eating Fish

What are Omega-3 Fatty Acids?

Most cooking oils are made up primarily of unsaturated fats. When it comes to choosing cooking oils, each type of cooking oil varies in its ratio of monounsaturated to polyunsaturated fats. Two oils stand out for their high levels of monounsaturated fats: canola oil and olive oil. Other than nonstick cooking spray, these two oils should be in your pantry.

Do Cooking Oils Contain Saturated Fat?

Heart-Healthy Canola Oil

What is Enova Oil?

Is Extra-Light Olive Oil a Low-Fat Cooking Oil?

At the end of the day, a good fat is still a fat in terms of calories. Any labels on cooking oil that describe the oil as "light," are referring to the taste or color, not the fat or calorie content. All oils are 100 percent fat and are worth around 120 calories per tablespoon.

The Bad: Saturated Fats

Then there are the bad fats—those artery-clogging saturated fats from meat and dairy products. These fats are solid at room temperature. Saturated fats not only clog our arteries, they also directly raise total and LDL (bad) cholesterol levels. Avoid them as much as possible.
What are the Main Sources of Saturated Fat?

Yes or No to Cheese?

Butter vs. Margarine

But, we are told, some saturated fats may not bad at all: some argue that coconut oil and palm oil may actually be beneficial because their particular fatty-acid make-up means they are metabolized differently in the body. So it could be that plant-based saturated fats may be more beneficial, or at least more neutral, than we think, but there is no broad consensus on this yet. And while coconut oil and palm fruit oil have been rehabilitated in the eyes of some, there are fewer proponents of palm kernel oil.

The increasing prevalence of diabetes and low carb diet craze has many people avoiding carbohydrates like the plague. While eating simple sugars in high amounts can be unhealthy and a risk factor for diabetes, complex carbohydrates are the main source of energy for the body and are necessary for any healthy diet. Because of the connection between insulin resistance, diabetes and PCOS, it's important to understand the relationship between glucose and insulin.

傳統(tǒng)飲食觀念中的脂肪已經(jīng)改變。以前,所有的脂肪都被認(rèn)為是不健康的,與各種各樣的疾病都有關(guān)系,從心血管疾病到糖尿病。但是這些年的研究已經(jīng)改變了我們的這種想法。我們先前并沒有公平的看待他們——有益的脂肪,有害的脂肪,也許不是那么有害或者非常壞。讓我們更進(jìn)一些去看他們。

有益的:不飽和脂肪

它聽起來很矛盾,他們確實(shí)是有益的脂肪,這種不飽和的物質(zhì)之所以可以完全對抗疾病是因為他能夠消耗過剩的脂肪。這種脂肪可以分辨出單一不飽和脂肪和多重不飽和脂肪。這兩種類型過去都被認(rèn)為受到膽固醇的有益影響。

單一不飽和脂肪可以降低LDL(有害的)膽固醇和提高HDL(有益的)膽固醇。

多重不飽和脂肪被認(rèn)為可以降低全部和有害的膽固醇。但是單一不飽和脂肪更傾向于有益的超過多重不飽和脂肪,因為一些研究指出多重不飽和脂肪更加不穩(wěn)定,減少有益的膽固醇水平與有害的相同。

但是讓我們忽略多重不飽和脂肪。他們有益于ω-3脂肪酸的循環(huán),他通常存在于魚類,堅果類,油,種子以及深色的多葉植物,亞麻油和植物油中。其中一種ω-3脂肪酸是我們身體所不能制造的“必需脂肪酸”,所以吃這些食物是我們得到他們的唯一途徑。ω-3脂肪酸可以降低血壓,與LDL(有害的)膽固醇和發(fā)炎做斗爭,保護(hù)大腦和神經(jīng)系統(tǒng)。

Heart-Healthy Walnuts
The Benefits of Eating Fish
What are Omega-3 Fatty Acids?

大部分食用油主要由不飽和脂肪組成。每當(dāng)選擇食用油時,每種都有各種各樣單一不飽和脂肪和多重不飽和脂肪的比例。菜油和橄欖油代表了高級單一不飽和脂肪,這兩種油應(yīng)當(dāng)在你的食品室。

Do Cooking Oils Contain Saturated Fat?
Heart-Healthy Canola Oil
What is Enova Oil?
Is Extra-Light Olive Oil a Low-Fat Cooking Oil?

到了最后,有益的脂肪始終還是有卡路里的脂肪,任何食用油的商標(biāo)上所描述的“少的”是涉及味道和顏色,并不是脂肪和卡路里的含量。每一大湯匙100%的脂肪和120的卡路里。

有害的:飽和脂肪

What are the Main Sources of Saturated Fat?
Yes or No to Cheese?
Butter vs. Margarine
 
但是,我們說,一些飽和的脂肪并不是全部有害的:一些關(guān)于椰子油的棕櫚油的爭論是認(rèn)為他們是有益的,因為他們特別的脂肪酸組成也就是說身體不同的新陳代謝。所以他的植物基礎(chǔ)飽和脂肪酸更加有利,或者比我們想的更加中立,但是還沒有更廣的一致性。當(dāng)椰子油和棕櫚油在一些人的眼里恢復(fù)時,將會有更少的棕櫚油的支持者。

隨著糖尿病的遞增和低卡路里飲食的流行,越來越多的人避免碳水化合物就像瘟疫一樣。如果吃的少但總量多的話也一樣不健康,同時有患糖尿病的危險。復(fù)雜的碳水化合物是人體能量的主要來源以及健康飲食所必須的。因為他聯(lián)系著糖尿病中胰島素的抵抗力和PCOS,他對于理解葡萄糖和胰島素之間的關(guān)系非常重要。