整個碳水化合物 VS 精製碳水化合物

The amount of carbohydrates we should consume is a hotly debated topic. Dietary guidelines recommend that we get about half of our calories from carbohydrates. On the other hand, some claim that carbohydrates may contribute to obesity and type 2 diabetes and should be avoided by most people. There are good arguments on both sides, but our bodies need carbohydrates to function properly. This article details carbohydrates, their health effects, and how to make the best choices for yourself.

What are carbohydrates?

Carbohydrates are molecules with carbon, hydrogen and oxygen atoms. In nutrition, "carbohydrate" refers to one of three macronutrients. The other two are protein and fat.

Dietary carbohydrates are divided into three main categories:

  • Sugars. These are sweet, short-chain carbohydrates found in foods. Examples are glucose, fructose, galactose and sucrose.
  • Starch. Tese are long chains of glucose molecules that are eventually broken down into glucose in the digestive system.
  • Fiber. Humans cannot digest fiber, but the bacteria in the digestive system can. Plus, eating fiber is crucial to your overall health.

One of the main purposes of carbohydrates in the diet is to provide fuel for the body.

Most carbohydrates are broken down or converted into glucose, which can be used for energy. Carbohydrates can also be converted into fat (stored energy) for later use.

Fiber is the exception. It doesn’t provide energy directly, but it feeds the friendly bacteria in your digestive system. These bacteria can use fiber to produce fatty acids that some of our cells can use for energy.

Sugar alcohols are also classified as carbohydrates. They taste sweet but usually don't provide many calories.

Summary

Carbohydrates are one of the three major nutrients. The main types of carbohydrates in the diet are sugar, starch and fiber.

“Whole” vs. “Refined” carbohydrates

Not all carbohydrates are created equal.

There are many different types of carbohydrate-containing foods, and their effects on health may vary.

Carbohydrates are sometimes called "simple" versus "complex," or "whole" versus "refined."

Whole carbohydrates are unprocessed and contain fiber naturally found in foods, whereas refined carbohydrates have been processed and the natural fiber has been removed or altered.

Examples of whole carbohydrates include:

  • Vegetables
  • Quinoa
  • Barley
  • Beans
  • Potato
  • Whole grains

Refined carbohydrates, on the other hand, include:

  • Sugary drinks
  • White bread
  • Pastry
  • Other items made with white flour

Numerous studies have linked refined carbohydrate intake to health conditions such as obesity and type 2 diabetes.

Refined carbohydrates tend to cause blood sugar levels to spike, leading to a subsequent crash that triggers hunger and leads to food cravings.

They are also often deficient in essential nutrients. In other words, they are "empty" calories.

Added sugars should be limited as they are linked to various chronic diseases.

But all carbohydrate-containing foods should not be demonized because of the negative health effects of processed foods.

Whole carbohydrate foods are rich in nutrients and fiber and don't cause the same blood sugar swings.

Extensive research on high-fiber carbohydrates, including vegetables, fruits, legumes, and whole grains, shows that consuming them is associated with improved metabolic health and reduced disease risk.

Summary

Not all carbohydrates are created equal. Refined carbohydrates have been linked to obesity and metabolic disease, but unprocessed carbohydrates have many health benefits.

Low carb diet dilemma

No discussion of carbs would be complete without mentioning low-carb diets.

These types of diets limit carbohydrates while allowing large amounts of protein and fat.

Although there are studies showing that low-carb diets can help you lose weight, they tend to focus on those with obesity, metabolic syndrome, and/or type 2 diabetes.

Some of these studies show that compared to a standard "low-fat" diet, a low-carb diet promotes weight loss and improves various health markers, including HDL "good" cholesterol, blood sugar, blood pressure, and more.

However, a review of more than 1,000 studies found that low-carbohydrate diets had positive results at 6-11 months and less, but had no significant effect on cardiovascular risk factors after 2 years.

Additionally, in the 1999-2010 U.S. National Health and Nutrition Examination Survey, an analysis of low-carbohydrate diets and risk of death found that those who consumed the least carbohydrates died prematurely from conditions including stroke, cancer and coronary heart disease.

Summary

Just because a low-carb diet works for some people when it comes to weight loss, it's not the way to go for everyone.

“Carbohydrates” are not the cause of obesity

Although carbohydrate restriction can lead to weight loss, this does not mean that consuming carbohydrates in the first place is itself a cause of weight gain.

This is actually a debunked myth.

It's true that added sugars and refined carbohydrates are linked to an increased chance of obesity, but the same cannot be said for fiber-rich, whole-food carbohydrates.

Humans have actually been eating carbohydrates in some form or other for thousands of years.

However, the incidence of obesity began to increase starting in the mid-20th century, starting around 1980, when 4.8% of men and 7.9% of women were obese.

Today, our numbers are growing exponentially, with 42.4% of adults suffering from obesity.

It is also worth noting that some groups of people remain in good health while eating a high-carbohydrate diet.

Okinawa and Kitavan Islanders, who get a large portion of their daily calories from carbohydrates, live longest.

What they all have in common is that they eat real, unprocessed food.

However, people who eat large amounts of refined carbohydrates and processed foods tend to have a greater chance of developing negative health consequences.

Summary

People have been eating carbohydrates since long before the obesity epidemic, and there are many examples of people who consumed a diet high in carbohydrates and still maintained good health.

Whole carbs vs. refined carbs

Carbohydrates are not “necessary,” but many carbohydrate-containing foods are very healthy

Many people on a low-carb diet claim that carbohydrates are not an essential nutrient.

This may be true to an extent, but they are an important part of a balanced diet.

Some people believe that the brain does not need the recommended 130 grams of carbohydrates per day. While some areas of the brain can use ketones, the brain relies on carbohydrates for its fuel.

In addition, carbohydrate-containing foods, such as vegetables and fruits, provide nutrients that have a variety of health benefits.

While it is possible to survive even on a zero-carb diet, it may not be the best choice because you miss out on plant-based foods that are scientifically proven to be beneficial.

Summary

Carbohydrates are not "essential" nutrients. However, many carbohydrate-rich plant foods are packed with beneficial nutrients, so avoiding them may not keep you feeling your best.

Whole carbs vs. refined carbs

How to make the right choice

Whole carbs vs. refined carbs
Generally, natural, fiber-rich carbohydrates are healthy, while carbohydrates stripped of fiber are not.

If it's a whole, single-ingredient food, it's probably a healthy food for most people, regardless of the carbohydrate content.

Instead of thinking of carbs as "good" or "bad," focus on choosing whole carbs and complex carb options.

Nutrition is rarely black and white. But the following foods are better sources of carbohydrates.

  • Vegetables. All of them. It is best to eat a variety of vegetables every day.
  • Whole fruit. Apples, bananas, strawberries, etc.
  • Beans. Lentils, kidney beans, peas, etc.
  • Nuts Almonds, walnuts, hazelnuts, macadamia nuts, peanuts, etc.
  • Seeds. Chia seeds and pumpkin seeds.
  • Whole grains. Choose grains that are truly whole, ranging from pure oats, quinoa, brown rice and more
  • Tubers. Potatoes, sweet potatoes, etc.

These foods may be acceptable in moderation for some people, but many people will achieve best results by avoiding them as much as possible.

  • Sugary drinks. These are sodas, sweetened juices, and drinks sweetened with high fructose corn syrup.
  • White bread. These are refined carbohydrates that are low in essential nutrients and have a negative impact on metabolic health. This works for most commercially available breads.
  • Pastries, cookies and cakes. These foods tend to be high in sugar and refined wheat.
  • Ice cream. While there are exceptions, most types of ice cream are high in sugar.
  • Candy and chocolate. If you're going to eat chocolate, choose high-quality dark chocolate.
  • French fries and potato chips. Whole potatoes are healthy. However, French fries and potato chips don't provide the nutritional benefits that whole potatoes do.
Summary

Natural, fiber-rich carbohydrates are generally healthy. Processed foods containing sugar and refined carbohydrates do not provide the same nutritional benefits as natural forms of carbohydrates and are more likely to cause adverse health consequences.

Whole carbs vs. refined carbs
Low carb works well for some people, but other carbs work best

There is no one-size-fits-all solution when it comes to nutrition.

The "optimal" carbohydrate intake depends on a variety of factors, such as:

  • Age
  • Gender
  • Metabolic health
  • Physical activity
  • Food Culture
  • Personal preferences

If you are overweight or have a medical condition such as metabolic syndrome and/or type 2 diabetes, you may be sensitive to carbohydrates. In this case, reducing carbohydrate intake may be beneficial.

On the other hand, if you're just trying to stay healthy, there's no reason to avoid "carbohydrates." However, it's still important to eat as many single-ingredient foods as possible.

If you have a naturally lean and/or physically active body type, adding lots of carbohydrates to your diet may even help your body function better.

Review

All comments are moderated before being published

HealthyPIG Magazine

View all
黑眼圈成因全解析:從生理、生活習慣到醫學對策

黑眼圈成因全解析:從生理、生活習慣到醫學對策

前言:為何黑眼圈總是揮之不去? 「黑眼圈」係現代人嘅常見問題之一。無論係通宵工作、壓力過大、過敏,甚至遺傳因素,都可能令眼底皮膚變黑或出現陰影。雖然多數情況屬於美容問題,但有時亦可能反映身體狀況,例如貧血、睡眠質素差、血液循環不良等 [1]。  一、黑眼圈的主要類型與成因 色素型黑眼圈(Pi...
智慧手錶 vs 專用 O₂Ring 血氧儀:血氧監測能力的科學比較

智慧手錶 vs 專用 O₂Ring 血氧儀:血氧監測能力的科學比較

1. 前言 血氧飽和度(SpO₂)是評估呼吸、循環系統狀態的重要指標。近年來,市面上兩大類可穿戴設備用於血氧監測: 智慧手錶(如 Samsung Watch、Apple Watch) 專用血氧監測設備(如 O₂Ring、指夾式脈搏血氧儀) 兩種設備的設計目的、測量方式、準確性、監測...
血氧飽和度、氧氣下降與「警戒線」的科學探討

血氧飽和度、氧氣下降與「警戒線」的科學探討

1. 前言 血氧飽和度(SpO₂)即血液中氧合血紅蛋白佔總血紅蛋白的百分比,是臨床及居家監測呼吸、循環功能的重要指標。當血氧飽和度下降,可能反映體內氧的供應或運送出現問題(低氧血症、hypoxemia)或更廣泛的組織缺氧(hypoxia)[1][2]。本文旨在探討: 血氧飽和度正常範圍與變...
冰敷(Cold Therapy)真正作用全面解析:止痛、減腫,還是幫助修復?|科學視角 + 實證文獻

冰敷(Cold Therapy)真正作用全面解析:止痛、減腫,還是幫助修復?|科學視角 + 實證文獻

冰敷(Ice Pack / Cold Therapy / Cryotherapy)係好多運動、急性受傷(如扭傷、撞擊、肌肉拉傷)時的第一時間處理方法。但不少人會疑惑: 「冰敷純粹止痛,定係真係會幫助組織修復?」「冰敷幾耐?冰敷幾多日?會唔會影響身體自然修復?」 本文從科學、醫學、運動治療角度,...
長時間保持同一姿勢後關節痛、僵硬、郁唔到:成因、科學解釋與改善方法

長時間保持同一姿勢後關節痛、僵硬、郁唔到:成因、科學解釋與改善方法

前言:為何「坐耐、蹲耐、跪耐」之後會痛? 無論係坐喺電腦前、跪低執嘢、長時間翹腳、側睡又唔郁——好多人體驗過一樣情況: 「一動就痛、一企起身腳軟、膝蓋直唔到、關節卡卡聲,又或者要行幾步先鬆返。」 其實呢種情況係非常普遍,而且通常並非關節已經壞死,而係 和關節生理、滑液循環、血液供應、肌肉張力 ...
魚醒味的科學:成因、風險與處理方法全面解析

魚醒味的科學:成因、風險與處理方法全面解析

「魚醒味」是華人烹飪文化中常見的說法,用以描述魚類在 解凍、切片或加熱後所突然出現的腥味、血水味或脂肪味。此現象並不代表食材變壞,但背後牽涉到蛋白質變化、脂肪氧化與揮發性化合物釋放等多種科學機制。本文將以科學角度剖析魚醒味的成因,並提供實證方法降低這種味道,同時探討其安全性。 🧪 什麼是「魚...
牛肉需唔需要清洗?科學解釋、處理方法與食安建議

牛肉需唔需要清洗?科學解釋、處理方法與食安建議

不少家庭煮食者都會問:「生牛肉需唔需要清洗先煮?」特別係買梅頭(Chuck Tender / Chuck Roll)呢類切件時,可能見到少量血水、碎肉、黏液,就會擔心細菌問題。根據多個食品安全機構研究,其實 生牛肉一般情況下無需清洗,而且清洗反而會提高交叉污染風險。 下文將由科學角度解釋理由,...
如何正確清洗草莓?鹽水、梳打粉、白醋邊樣最好?科學比較+實證指南

如何正確清洗草莓?鹽水、梳打粉、白醋邊樣最好?科學比較+實證指南

草莓鮮甜多汁,但表面凹凸、種子細小,容易殘留泥沙、蟲卵、細菌與農藥殘留。市面上很多清洗方法,包括鹽水、醋水、梳打粉、臭氧水等,但到底邊樣真正有效、又不會破壞草莓的營養與口感? 今次文章從 科學研究與食物安全角度 分析不同清洗方法的原理、有效程度與正確用法,並提供一套 最安全、最有效的草莓清洗流...
牛肉與腸道微生態:人體點樣反應?

牛肉與腸道微生態:人體點樣反應?

牛肉進入身體之後會發生咩事? 食牛肉之後,身體會進入「高蛋白消化模式」: 胃部階段:胃酸(pH約2)與胃蛋白酶一齊將牛肉蛋白質分解成小分子胺基酸鏈。此時釋放「胃泌素(gastrin)」促進更多酸及酶分泌。 小腸階段:十二指腸接收食糜後,胰臟釋出胰蛋白酶、脂肪酶,肝臟釋出膽汁乳化脂肪。 ...