I believe many of my friends who are in the process of losing fat have heard of this suggestion. It is best to eat low GI food and avoid high GI food. Some even invented the “slow carbon water diet.”.
But do you really have to eat low GI food during the fat loss period? High GI food can’t be touched? Is GI value of food important for weight loss?
In the following content, I will answer these questions for you.
What is the GI value?
GI value, yes blood sugar The abbreviation of index (glycemic index).
The first study on glycemic index was published in 1981. The subjects were fed 50g of pure glucose on an empty stomach after a night’s fasting, and their blood glucose response was measured two hours after the meal.
Then, the subjects continued to eat the same amount of 50 grams of carbohydrates. The researchers measured the blood glucose response again, and then compared the two to get the glycemic index of a certain food. Therefore, the reference standard of GI value is glucose.
Generally speaking, the higher the GI value of food, the faster the speed of digestion and absorption, and the faster the blood sugar rises. The lower the GI value of food, the slower the speed of digestion and absorption, and the slower the increase of blood glucose.
GI value and fat reduction
People who claim that they can only eat low GI foods tend to hold the view that high GI foods can lead to a rapid rise in blood sugar, which leads to a large amount of insulin, which stores fat.
Strictly speaking, there is no problem with this sentence. But when do you need to worry? Take a look at this picture:
If you eat a high GI diet, the green part of the picture above causes insulin secretion, which leads to fat synthesis. But when you don’t eat (the blue part), insulin production decreases and fat breaks down. During the day, the decomposition and synthesis of fat are dynamic. As long as your energy intake doesn’t exceed your energy consumption throughout the day, there won’t be much fat synthesis.
Therefore, it is not very strict to think that high GI food secretes insulin, which leads to fat storage and makes people fat. It still depends on the net energy balance throughout the day.
Some problems of GI value
As I mentioned above, GI is the value of a carbohydrate consumed alone compared to glucose on an empty stomach after a night’s fasting. What’s wrong with this in the real world?
first, Very few people eat a single carbohydrate in a meal (drink lots of sweet on an empty stomach Drinks Except, it should be rare for people to do so. When we eat carbohydrates, we tend to eat some fat Vegetables Protein, etc.
And we know that fat can slow down the digestion of food and delay gastric emptying. In addition, vegetables generally contain rich dietary fiber, dietary fiber also has the same function. Therefore, with the intake of these nutrients, the overall GI value of this meal will be greatly reduced.
Second, what many people don’t know is, The glycemic index of a food can vary by 20% in one person and 25% in different people [2]。 So GI is very limited in predicting how food affects glycemic index.
Third, if you really want to eat low GI food to lose fat as many people say, then the GI value of potatoes is higher than that of French fries. Why does no one recommend eating french fries to lose weight? In addition, many of our common snacks, as well as some “junk food”, such as pizza, ice cream and hamburger, have low GI values. You obviously don’t eat a lot of these foods because of their low GI values.
Finally, although some studies have shown that low GI foods are fuller than high GI foods and can lead to better fat loss, this view has been questioned.
For example, a systematic review in 2002 compared the effects of a high GI diet and a low GI diet on appetite, food intake, energy consumption, and weight [3]. Thirty one short-term studies (less than one day) were included in the analysis, of which 15 found that low GI foods were associated with higher satisfaction or reduced hunger, while 16 studies found that low GI foods reduced satisfaction or had no difference. In addition, in 20 long-term studies (less than 6 months), the average weight loss of low GI diet was 1.5kg, and that of high GI diet was 1.6kg.
Therefore, it is unclear whether low GI foods are better than high GI foods for long-term weight control.
How to choose food?
Based on the above analysis, I think you should know that it is not advisable to pay too much attention to the GI value of food when reducing fat. Different people, food differences will be very large, and in real life, the use of GI value is also very limited, and little significance.
At the end of the day, losing fat is still a matter of energy balance. To take an extreme example, if you eat “healthy food” such as chicken breast, broccoli, brown rice every day, but your activity is very low, and the final intake exceeds the consumption, you will still be fat. So if you eat it every dayMcDonald’s , or some other “junk food”, as long as you control the total amount, ensure the intake of protein, and then exercise regularly and consume more, you can still be thin.
Of course, these are two more extreme examples, I’m mainly trying to tell you not to think of food as “good” or “bad.”. High GI food is not heinous, and low GI food is not enough to eat in large quantities 。
In general, for people who lose fat, I suggest that you focus on the total calories of the day first, and then the quality of the food. If you can’t completely reject junk food, you can use the 80 / 20 principle. That is, 80% of your daily food comes from vegetablesFruits Protein and low degree of processing of food, these foods have a strong sense of satiety, can provide you with some necessary nutrients, ensure the normal operation of the body function. The remaining 20% of the food can be “less healthy”, anything you like. In this way, we can better adhere to the current diet, so as to achieve the effect of reducing fat.
It is not advisable to limit certain foods completely, which will only lead to excessive craving for these foods, and then burst out.
summary
If you want to lose fat, you don’t have to eat low GI food. GI is not as important to lose weight as many people say. Instead, you need to focus on total calories and overall quality of your diet, and choose a diet that you can stick to for a long time to get the best results.