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.

传统饮食观念中的脂肪已经改变。以前,所有的脂肪都被认为是不健康的,与各种各样的疾病都有关系,从心血管疾病到糖尿病。但是这些年的研究已经改变了我们的这种想法。我们先前并没有公平的看待他们——有益的脂肪,有害的脂肪,也许不是那么有害或者非常坏。让我们更进一些去看他们。

有益的:不饱和脂肪

它听起来很矛盾,他们确实是有益的脂肪,这种不饱和的物质之所以可以完全对抗疾病是因为他能够消耗过剩的脂肪。这种脂肪可以分辨出单一不饱和脂肪和多重不饱和脂肪。这两种类型过去都被认为受到胆固醇的有益影响。

单一不饱和脂肪可以降低LDL(有害的)胆固醇和提高HDL(有益的)胆固醇。

多重不饱和脂肪被认为可以降低全部和有害的胆固醇。但是单一不饱和脂肪更倾向于有益的超过多重不饱和脂肪,因为一些研究指出多重不饱和脂肪更加不稳定,减少有益的胆固醇水平与有害的相同。

但是让我们忽略多重不饱和脂肪。他们有益于ω-3脂肪酸的循环,他通常存在于鱼类,坚果类,油,种子以及深色的多叶植物,亚麻油和植物油中。其中一种ω-3脂肪酸是我们身体所不能制造的“必需脂肪酸”,所以吃这些食物是我们得到他们的唯一途径。ω-3脂肪酸可以降低血压,与LDL(有害的)胆固醇和发炎做斗争,保护大脑和神经系统。

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

大部分食用油主要由不饱和脂肪组成。每当选择食用油时,每种都有各种各样单一不饱和脂肪和多重不饱和脂肪的比例。菜油和橄榄油代表了高级单一不饱和脂肪,这两种油应当在你的食品室。

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,有益的脂肪始终还是有卡路里的脂肪,任何食用油的商标上所描述的“少的”是涉及味道和颜色,并不是脂肪和卡路里的含量。每一大汤匙100%的脂肪和120的卡路里。

有害的:饱和脂肪

What are the Main Sources of Saturated Fat?
Yes or No to Cheese?
Butter vs. Margarine

但是,我们说,一些饱和的脂肪并不是全部有害的:一些关于椰子油的棕榈油的争论是认为他们是有益的,因为他们特别的脂肪酸组成也就是说身体不同的新陈代谢。所以他的植物基础饱和脂肪酸更加有利,或者比我们想的更加中立,但是还没有更广的一致性。当椰子油和棕榈油在一些人的眼里恢复时,将会有更少的棕榈油的支持者。

随着糖尿病的递增和低卡路里饮食的流行,越来越多的人避免碳水化合物就像瘟疫一样。如果吃的少但总量多的话也一样不健康,同时有患糖尿病的危险。复杂的碳水化合物是人体能量的主要来源以及健康饮食所必须的。因为他联系着糖尿病中胰岛素的抵抗力和PCOS,他对于理解葡萄糖和胰岛素之间的关系非常重要。