Wednesday, December 27, 2023

What is 血糖生成指數 Glycemic Index?

血糖生成指數 Glycemic Index and 卡路里統計 Calories Statistics of The O Lemon vs Teh Tarik:
不加糖熱檸檬茶 Hot Lemon Tea w/o Sugar: +10 Calories and +20 GI Index 
馬來西亞奶茶(拉茶) Teh Tarik with Sugar and Condensed Milk: +200 Calories and +80 GI Index. 
    - One of the main reasons why the latest statics shows that 50% of the Malaysian population are overweight and 1 of 5 people have diabetic symptoms or are diabetics is because of continuous High Calories and Higher GI index daily food consumptions !!!!

What is 血糖生成指數 GI Index (or Glycemic Index)?
  
The term "血糖生成指數 Glycemic Index (GI)" was introduced in 1981 by 大衛·J·詹金斯 David J. Jenkins (英國營養科教授) British-born University Professor) and co-workers (拿大多倫多大學營養科學系) in Toronto University, Canada. The GI Index was developed as a useful measurement for quantifying the relative rapidity with which the 身體分解碳水化合物 body breaks down carbohydrates. It takes into account only the available carbohydrate (總碳水化合物減去纖維 total carbohydrate minus fiber) in a food.

The "血糖生成指數 Glycemic Index (GI)" is a number from 0 to 100 assigned to a food, with pure glucose arbitrarily given the value of 100, which represents the relative 血糖值升高 rise in the blood glucose level two hours after consuming that food. The GI of a specific food depends primarily on the quantity and type of Carbohydrate it contains.

Research indicates that 碳水化合物過多 Excess carbohydrate intake 身體無法負荷代謝 places a large metabolic load on the body. When the body constantly has high levels of blood sugars (the end point of food sugar and starch) to deal with over time, this leads to 體重增加 weight gain, 代謝健康狀況不佳 poor metabolic health and an 心臟病的風險增加 increased risk of heart disease. And this is more prevalent for people above 50 where metabolism slows down with age and increasing lack of mobility or exercise.

Some research indicates that one of the major flaws with 血糖生成指數 Glycemic index is that it doesn't take into account how much food you have consumed. The GI value designed is based on a fixed portion size, typically 50 grams of available carbohydrates. This approach overlooks the fact that different people consume different quantities of food. Also, Combining different carbohydrate foods with different individual GIs also alters the overall GI of that meal. A composite meal with protein and added fat for cooking also alters the GI of the meal itself. Nevertheless, the GI index as available for different food provides a simple means (reference) for food choices especially people who are weight conscious as well as 糖尿病前期 pre-diabetic and 糖尿病患者 Diabetics.

大衛·J·詹金斯 David J. Jenkins and his team recommended Low GI food for a healthier diet with the following reference guideline:

低升糖指數 Low GI : 1 to 55 (smaller spikes in blood sugar)
中等糖指數 Medium GI : 56 to 69 (relative higher spikes in blood sugar)
高糖指數 High GI : 70 and higher to max of 100 (high spikes in blood sugar)

The glycemic index ranks food on a scale from 0 to 100. The low end of the scale has foods that have little effect on blood sugar levels. The high end of the scale has foods with a big effect on blood sugar levels. The 血糖生成指數理論 Glycemic index (GI) theory tells us whether a carbohydrate-containing food raises blood glucose levels quickly, moderately or slowly. This means it can be a simple guideline generally useful to help you manage a person's sugar level (diabetes) and weight control efforts.

Example of Food GI Index (as a reference):
GI Index of 0 (Low GI): 水 Water, 牛肉 Beef, 豬肉 Pork, 蛋 Eggs
GI Index >=0 but <=55 (Low GI): 酪梨 Avocado, 藍莓 Blueberry, 綠色蔬菜 Green Vegetables, 豆類 Beans, 豆腐 Tofu
GI Index >55 but <=69 (Medium GI): 柳橙汁 Orange juice, 蜂蜜 Honey, 香蕉 Banana, 椰漿飯 Nasi Lemak
GI Index >69 (High GI): 馬鈴薯 Potatoes, 白麵包 White bread, 短粒米 Short-grain Rice, 拉茶 Teh Tarik, 糯米雞 Loh Mai Kai, 印度煎餅Roti Canai

A 低升糖指數(低GI)飲食 low-glycemic index (low-GI) diet is an eating plan based on how foods affect blood sugar level, also called blood glucose level. The low end of the GI index scale like a glass of Lemon Tea without Sugar are digested more slowly, prompting a more gradual rise in blood sugar (降低血糖峰值 lower Blood Sugar Spikes). therefore is a type of food that have little effect on blood sugar levels. While a glass of the Malaysian favorite of 馬來西亞奶茶(拉茶) frothy Teh Tarik has very high Sugar content with the very High GI of 80 means it will be rapidly digested (absorbed into the blood) and cause substantial fluctuations in blood sugar (高血糖峰值 high Blood Sugar Spikes after consumption).

When consuming too much sugar with 高糖指數食物 high GI foods, Calories will quickly add up in the body 更多的胰島素來分解所有的糖 will need more insulin to break down all the sugar. Without enough 胰島素 insulin, glucose builds up in the bloodstream instead of going into the cells. This buildup of glucose in the blood is called 高血糖 hyperglycemia. The body is unable to use the glucose for energy and will lead to the symptoms of 一型糖尿病 Type 1 Diabetes.

馬來椰漿飯配蘇東和蛤蜊 Nasi Lemak w/Sotong Kerang rm$8 & 奶茶 Milk Tea rm$2.20 @ 相有海鮮餐餐室 Restoran Wai Kwan USJ6 Goodyear Court 2

A breakfast of 參巴蘇東椰醬白米飯 Nasi Lemak with Squid Sambal plus 拉茶 Teh Tarik

椰醬白米飯 Coconut milk-based white Rice (Nasi Lemak) GI index of 96 (high)
烏賊 Squid is said to have GI index of 0 but 參巴蘇東 Squid Sambal no idea
煮雞蛋 Boiled egg GI index is 0 (low)
黄瓜 Cucumber GI index is 1 (low)
炒花生 Roasted Nuts GI index is 20 (low)
炸江魚仔 Fried Anchovies GI index likely low 
奶茶(拉茶) Teh Tarik GI index is at least 80 (high)

Even if you replace the white rice with basmati rice or brown rice, without the coconut milk (GI of 96); it wouldn't been nasi lemak anyway! AND at least the sample Nasi Lemak above have 2 items which are high in GI index. However, GI index isn't the only measure in healthy food; as it is likely that the 參巴蘇東 Sambal Squid and 炸江魚仔 Fried Anchovies are cooked with 高鈉(鹽) high sodium (salty) and 高飽和脂肪 Saturated Fat which aren't good measurements of a healthy meal. More over, the example Nasi Lemak is probably around 800-900 Calories which is already around 50% of the required Calorie for an adult person per day. Worst is that this concoction is the breakfast of the day!!!! So, a moderate consumption of Nasi Lemak as breakfast is a good idea OR if Nasi Lemak is the craving then have it for the Main Meal maybe as Lunch, then just 1 more lighter meal (of lower Calories and at least medium if not low GI index) for dinner. This is such that there isn't any continuous "Sugar Spikes" throughout the day due to consecutive meals having higher GI indexes as well as high calories.

In the long term, 血糖反覆升高 repeated spikes in your blood sugar can cause 心臟問題 heart problems, 腎臟問題 kidney problems, 視力問題 problems with eyesight, and 神經損傷 nerve issues like 神經病變 Neuropathy, where you lose feeling in fingers and toes.

References:
https://www.runsociety.com/food-nutrition/25-diabetes-friendly-local-foods-to-eat-in-singapore/
https://cnalifestyle.channelnewsasia.com/asian-foods-glycaemic-inde/