Essential Guide to Carbohydrates

Carbohydrates are controversial among people试图减肥。Because individual carbohydrate needs aren’t one-size-fits-all, we’ve put together an informational guide to help you optimize your carbohydrate consumption and choose healthier options, whether you’re trying to lose weight,训练您的前半程马拉松or anything in between.

Carbohydrates are found in almost all foods and provide 4 calories per gram. As you can imagine,not all carbohydrates are created equal。不同的碳水化合物对您的身体有所不同。含碳水化合物的食物通常具有两种类型的碳水化合物的组合：简单而复杂。

Simple carbsare also known as “sugar。” It’s made of up to two sugar building blocks connected in a chain. The building blocks can be glucose, fructose and galactose. Because the chains are short, they’re easy to break down, which is why they taste sweet when they hit your tongue. They are also digested and absorbed into the bloodstream quickly.

较高的简单碳水化合物的食物包括甜味剂(table sugar, syrup, honey), candy, jellies and jams and refined flour. Fruits, vegetables, beans and dairy contain simple carbs, too, but they come with vitamins and minerals, plus fiber and/or protein, so they’re still healthy choices.

Complex carbs can be either “starch” or “fiber.” This carbohydrate is made of three or more sugars connected in a chain; they also contain fiber and tend to come in foods that also contain蛋白质and/or健康的脂肪， 也维生素和矿物质。They use the same sugar building blocks as simple carbs, but the chains are longer and take more time to break down, which is why they don’t taste as sweet. The longer chains also slow digestion and thus absorption of the monosaccharides all carbs are broken down into, resulting in a more gradual insulin response, as well as increased satiety. Foods high in complex carbohydrates includebread，，，，rice，，，，pasta，，，，beans，，，，whole grainsand vegetables.

Fiber is a carbohydrate，，，，but it doesn’t contribute much to calories because it can’t be broken down and absorbed by the body. Just looking at a nutrition label, you’ll see “dietary fiber” and “sugar” listed under “total carbohydrates,” but the grams never add up. That’s because “total carbohydrates” includes all the types of carbohydrates: sugar, fiber and starch. Sugar and fiber get a starring role on the nutrition label because we care about them. However, starch doesn’t, so if you want to figure out how much starch a food contains, you have to do some math using the following formula:

总淀粉（克）=总碳水化合物（G） - 饮食纤维（G） - 糖（G）

In theory, net carbs are the amount of carbs from your food that can affect your blood sugar levels.The thinking behind net carbs那是不溶性纤维和糖酒（不被人体消化，不进入血液）不应计入您的整体碳水化合物摄入量。净碳水化合物的概念随着出现而流行keto阿特金斯饮食法。计算净碳水化合物the total grams of carbohydrates and subtract the grams of dietary fiber and sugar alcohols.

Net Carbs = total carbohydrate (g) – dietary fiber (g) – sugar alcohols (g)

However, it’s important to note “net carbs” is not a scientifically-defined term and isn’t regulated by the FDA on food packaging. Certain fibers and sugar alcohols, particularly the kinds that areadded to processed foodsto lower the net carb content, can be at least partially digested and affect blood sugar levels. This is why it’s a good idea toprioritize whole foods通常，在跟踪净碳水化合物时。美国以外的大多数国家都不将纤维或糖醇计入食品标签上的碳水化合物总数，因此他们已经在跟踪净碳水化合物作为标准实践。如果您要跟踪净碳水化合物以管理血糖，请务必先与您的医生联系。

When it comes to choosing carbohydrates to eat or drink, nutrient-dense sources are the way to go. Here are three rules to help you choose well. One caveat: If you’re ahighly athletic person他们的愿望是优化性能，并非所有这些碳水化合物规则适用于您。读这个反而。

Vegetables, beans, nuts and seeds, 100% whole-grain breads, pasta and brown rice should also be included in this rule. These foods are a source of fiber, vitamins, minerals and protein.

Foods like white rice, white bread and traditional pasta are more processed and have healthy nutrients — namely fiber — stripped from them.

Most sources of simple carbohydrates are considered “空卡路里”因为它们的卡路里含量很高，但几乎没有微量营养素。在刺激血糖时，它们可能是罪魁祸首。水果和牛奶是该规则的例外，因为它们含有有益的维生素和矿物质。

要执行基本功能，我们的身体需要碳水化合物，尤其是葡萄糖，因为它是组织和器官的首选燃料，也是我们红细胞的唯一燃料。没有足够的碳水化合物，人体会分解肌肉和器官中的来之不易的蛋白质，以产生可用的葡萄糖。

碳水化合物的建议饮食津贴（RDA）每天为130克。这是为成年人的大脑，红细胞和中枢神经系统加油所需的最低量。没有足够的碳水化合物来维持您的血糖，身体开始将蛋白质（瘦肌肉组织）分解为葡萄糖，以使血糖恢复正常。

每天130克碳水化合物的RDA是成人身体正常运行的最小值。大多数人需要更多。根据Dietary Guidelines for Americans，，，，carbohydrates should make up 45–65% of total calories in our diet. It’s such a big range because our bodies are all different and there’s no one-size-fit-all guidance for the absolute amount of carbs you should consume.

myfitnesspalallots 50% of your calories to carbohydrates, but we encourage you to change these goals based on your personal needs.

To determine your carbohydrate needs in grams:

1. Decide what percentage of carbohydrates you need and convert that number to a decimal (for example, 50% is 0.5).
2. 将您的“总卡路里目标”乘以十进制价值。这为您提供了来自碳水化合物的卡路里数量。
3. Divide that number by 4 to get the grams of carbohydrates.

If you’re not sure what percentage might be most appropriate, read more about how to优化您的大量营养素范围，或遵循此一般经验法则：

如果您想减肥，请首先将碳水化合物的摄入量保持在卡路里的45-50％。如果您每天进行超过1小时的锻炼或参加马拉松等耐力活动的训练，那么您可能会在55-65％的范围内做得更好。

A traditional “low-carb” diet含有40%或更少的卡路里来自碳水化合物吗。There’s no denying that many have lost weight and kept it off successfully with this lifestyle. It’s popular for a reason, but it certainly is not the only way to lose weight — and it may not be for everyone.

吃低碳水化合物饮食（尤其是一个限制性）影响您的blood sugar levels，，，，which can cause unfavorable side-effects in some people, including being mildly to downright uncomfortable, shakiness, nervousness or anxiety, chills, irritability, lightheadedness, headaches, hunger, nausea, fatigue, blurred vision, lack of coordination and more. These effects and the restriction required can make a low-carb diet difficult to stick with.

如果您选择试验少量碳水化合物，这里有七个提示，可以使过渡可持续：

It may be tough to tell your reaction to low blood sugar since it varies from person to person. When starting a low-carb diet, be on the lookout for the signs and symptoms of low blood sugar (see above). If you experience them, eat a small serving of a carbohydrate-rich snack such as a piece of fruit, some crackers or a slice of bread.

Use应用要跟踪食物至少一周，以便您可以很好地了解每天食用多少克碳水化合物。然后，每周慢慢降低碳水化合物摄入目标5-10％（或每天约30-50克），直到达到所需的目标。记住要增加脂肪和蛋白质目标，以抵消您从饮食中减少的碳水化合物。

Tracking net carbs is most beneficial if you’ve decided that a low-carb diet is best for you, says registered dietitian Stepanie Nelson. “It allows for greater food flexibility and makes it easier to hit your fiber goal without going over your carb goal. Fiber is important for cardiovascular health, digestive health and feelings of fullness.” It’s also helpful to track net carbs “if you’re concerned about keeping your blood sugar levels in check, since it can help you keep tabs on the foods that actually impact your blood sugar,” she notes.

如果您想尝试，现在可以跟踪总净碳水化合物in each food, meal and day in the MyFitnessPal app.

使这些碳水化合物计算choosing high-quality carbohydrates- 像全谷物，水果和蔬菜一样，富含纤维，维生素和矿物质。选择高质量的蛋白质，例如鸡蛋，豆类，鸡肉，豆腐和牛肉和猪肉瘦肉。从含有单不饱和和多不饱和脂肪的食物中选择健康的脂肪，例如鱼，坚果，鳄梨和橄榄油。

If you’re slashing carbs, you’ll most likely eat (and digest) more protein. For your body to break down and use protein optimally, it’s going to need plenty of water. Check out these20 ways to drink more water。

If you shed more than 2 pounds per week, be careful. You’re likelylosing more water weightand lean muscle than fat. Up your calories to lose weight at a slow but fat-busting pace.

Be honest with yourself: Are you happy eating a low-carb diet? Do you feel good? Our bodies can adapt to eating varying amounts of carbohydrates, but for some, the carbohydrate cravings and blood sugar side effects can be constant struggles. If you feel like your diet is too low in carbohydrates, don’t be afraid to add some back. Aggressively cutting carbs不是减肥的唯一方法，，，，and certainly isn’t for everyone. Keep this in mind because you’re more likely to stick to your goals, lose weight and keep it off if you feel good and are happy with what goes into your body.

坚持您的低碳水化合物目标跟踪总净碳水化合物在MyFitnessPal应用中。