Can diester oil help lose weight and lower blood lipids? Is it really that good?

gossip

"Diester oil is better than ordinary oil in losing weight and lowering blood lipids."

In recent years, "diester oil" has become a star product. Many companies claim in their promotions that diglyceride cooking oil (diester oil) is healthier than ordinary cooking oil, and even say that it can help lose weight and lower blood lipids.

Rumor Analysis

That is not the case.

The biggest difference between diester oil and ordinary cooking oil is that this oil has a higher proportion of diglycerides and a much lower proportion of triglycerides. There is still insufficient scientific evidence on the health benefits of diester oil, such as lowering blood lipids and losing weight.

People often say that we should "eat less oil and eat good oil". As a result, various "good oils" have emerged. In recent years, "diester oil" has become a star product. Major companies have launched "diester oil". Many companies claim in their publicity that compared with ordinary cooking oil, diglycerol edible oil (diester oil) is healthier, and even say that it can lose weight and lower blood lipids. What exactly is diester oil? Can it really help lose weight and lower blood lipids? Can you eat it as much as you want?

What is diester oil?

What exactly is diester oil? How is it different from the edible oil we often eat? Diester oil (diacylglycerol oil, DAG), also known as diglyceride edible oil, is a special edible oil. An announcement issued by the National Health Commission on August 3, 2021 shows that the production process of diester oil is based on soybean oil, rapeseed oil, etc. as raw materials, lipase preparations, water, glycerol, etc. as main auxiliary materials, through lipase catalysis, distillation separation, decolorization, deodorization and other processes. Its main feature is that the content of diglycerides is more than 40%. The content of triglycerides (TAG) in the edible oils we often eat will be higher. Therefore, the biggest difference between diester oil and ordinary edible oil is actually that the proportion of diglycerides in this oil is higher, while the proportion of triglycerides is greatly reduced.

In fact, diglyceride oil is not a recent product. It has been approved for use by various countries a long time ago. It is only in recent years that businesses have begun to market it. The U.S. Food and Drug Administration (FDA) included diglyceride oil in the list of "Generally Recognized as Safe" (GRAS) in 2000, and the European Food Safety Authority (EFSA) also passed the safety certification for diglyceride oil in 2005. In China, the former Ministry of Health approved diglyceride oil as a new food ingredient in 2009, and the National Health Commission revised the quality requirements for diglyceride oil in 2021, clarifying its production process and diglyceride content standards.

Can diester oil help lose weight and lower blood sugar?

Many businesses claim in their promotions that diester oil can help lose weight, lower blood sugar, and lower blood lipids. So is diester oil really that good? Are these health functions of its reliable?

The main component of ordinary cooking oil is triglyceride, which is enzymatically hydrolyzed into 2-monoglyceride (MG) and free fatty acids (FA) in the small intestine, and resynthesized into triglyceride in the small intestinal epithelial cells, which may then accumulate as body fat. In contrast, since the diglyceride in diester oil only connects two fatty acid molecules in its molecular structure, it cannot form a triglyceride structure and enter the blood after digestion and absorption, so it does not accumulate fat in the body, but instead supplies energy through mitochondrial metabolism, helping to reduce body fat and fat in the internal organs. Therefore, many people say that diester oil has the effects of losing weight and lowering blood lipids.

However, there is still insufficient scientific evidence on the health benefits of diester oils, such as lowering blood lipids and losing weight. There are indeed many studies on the effects of diester oils on blood lipids and body weight, but there are often many vested interests behind them. This greatly reduces the credibility of the results of studies on diester oils for weight loss and lowering blood lipids.

Many businesses often say in their promotions that diester oil has been approved by the United States (FDA), the European Food Safety Authority (EFSA), the Food Standards Australia New Zealand (FSANZ), and my country, making people think that the benefits of diester oil are certified.

There is a big logical trap here. In fact, these institutions have only evaluated the safety of diester oil, but not its health functions. The evaluation results show that it is safe and can be eaten and used, but these institutions have not certified that diester oil has functions such as weight loss and lowering blood lipids. In fact, at present, these institutions have not issued relevant health claims for diester oil, and have even rejected health claims about weight loss.

In 2011, a Japanese brand submitted an application to the European Food Safety Authority (EFSA) for a health claim about diester oil for weight loss. The application materials mentioned seven randomized controlled trials (RCTs), one of which had major methodological limitations; the results of the other six randomized controlled trials on the effect of replacing triglyceride oil (TAG oil) with diglyceride oil (DAG oil) on body weight were also inconsistent. In the end, the European Food Safety Authority (EFSA) evaluated that there was no causal relationship between diester oil and weight loss and rejected the application.

You should know that diester oil is also oil, it just has more diglycerides, more than 40%, but it still has triglycerides. Eating more is also energy, and it will also make you fat. As for the research on lowering blood lipids and blood sugar, there are even fewer studies in this area, and it is not enough to submit an application for health claims to the relevant departments (such as the European Food Safety Authority EFSA). Therefore, from the current point of view, there is insufficient evidence for the functions of diester oil in weight loss, lowering blood lipids, and lowering blood sugar. Diester oil is safe to eat, but it cannot lower blood sugar, lower blood lipids or lose weight.

How to eat oil healthily?

1. Eating less oil is the key

Diester oil is also oil, eating more will make you fat. Don't think that eating more will have any benefits.

At present, the average daily fat energy supply ratio of Chinese residents is 34.6%, which has exceeded the recommended range of 20%~30% for fat energy supply ratio. Among them, our average daily cooking oil intake per person is 43.2 g, which greatly exceeds the recommended 25g~30g. Therefore, the current priority is to eat less oil. Controlling the amount of oil used in family kitchens, canteens, and restaurants is crucial for oil control and oil reduction. For this reason, the slogan of this year's Nutrition Week is "Reduce oil, increase soybeans and add milk", with oil reduction ranking first.

It is recommended that you eat oil, no matter what kind of oil it is, in moderation, not exceeding 25g~30g per day.

2. Buy rationally and within your means

Compared with ordinary cooking oil, the price of diester oil is relatively higher. Ordinary 500 ml peanut oil is only 20 yuan, while the price of diester oil of the same specification is more than 100 yuan at the lowest. And the higher the diglyceride content, the higher the price. Everyone should buy rationally and within their means.

Looking in the mirror of rumors

When an ordinary product is given medical functions, we should be careful. Don't be misled by propaganda and stay vigilant.

Author: Ruan Guangfeng, Deputy Director of Kexin Food and Health Information Exchange Center

Review丨Zhang Yu, researcher/PhD, Chinese Center for Disease Control and Prevention, national health science expert