Celebrities were fined for endorsing weight loss products. Don’t buy weight loss products with this kind of ingredients!

Recently, the news #Jing Tian was punished for illegal advertising endorsement# became a hot topic. A brand of fruit and vegetable weight loss products endorsed by actress Jing Tian was exposed for false advertising and became a hot topic. The total fine was 7.2212 million yuan.

▲Photo: Screenshot from Weibo

The product claims in its promotion that it has the effect of "blocking the absorption of fat and sugar", and some promotional pictures also read "Don't be afraid of oil and sugar, you can eat as much as you want without getting fat."

The main ingredients of this product are white kidney bean extract, Flammulina velutipes extract and various fruit and vegetable ingredients. Among them, white kidney bean extract is an ingredient found in many weight loss products.

Regarding white kidney bean extract, this article will analyze whether it is reliable to eat it for weight loss.

1. What are white kidney beans?

White kidney bean is a legume plant, also known as common bean, white kidney bean, and white kidney bean. It is native to America and is also grown in my country, mainly in Yunnan, Sichuan, and Guizhou.

Nutritionally, it is rich in protein and dietary fiber, with the content of the two being nearly 1.2 times and 1.3 times that of red beans respectively, and the calories are slightly lower than red beans.

You can put it in rice to make mixed bean rice, which is a good combination of coarse and fine staple foods, and can also increase the intake of protein, dietary fiber and B vitamins.

In addition, some studies have shown that white kidney beans contain white kidney bean alpha-amylase inhibitors. [1]

2. Why is it rumored that “white kidney bean extract” can help lose weight?

White kidney bean α-amylase inhibitor can specifically inhibit the activity of α-amylase in human saliva and intestines, hindering or delaying the hydrolysis and digestion of carbohydrates in food, thereby reducing the body's calorie source and delaying the absorption of sugars. [1]

About its animal studies:

The α-amylase inhibitor extracted from white kidney beans in Yunnan was used for an experiment on SD rats. Three dose groups of kidney bean extract α-amylase inhibitor were administered orally for 45 days in high (352 mg/kg), medium (141 mg/kg), and low (70 mg/kg) doses. The results showed that the body weight, peritesticular fat pad mass, and total blood cholesterol of SD rats were reduced. [2]

Human studies on it:

1. A trial selected 101 obese and overweight subjects and asked them to take 1000 mg of α-amylase inhibitor every day for 60 consecutive days. The results showed that the subjects lost an average of 1.9 kg in weight and 1.9 cm in waist circumference. [3]

2. A review published in the journal "Nutrients" in 2020 also mentioned a study in which 114 obese adults were the subjects. The experimental group took 800 mg of white kidney bean extract before each meal, and the placebo group took maltodextrin. After 35 days, the experimental group lost an average of 2.24 kg and 1.95 kg in weight and fat, respectively, while the placebo group lost an average of 0.29 kg in weight and 0.5 kg in fat.

If you only look at these data, many people will think that white kidney bean extract is still effective for weight loss.

However, it should be noted that the quality of these studies is not high and the sample size is small. In addition, in the first experiment mentioned in the human study, it took only 2 months to lose 1.9 kg and the waist circumference decreased by 1.9 cm. This speed can be easily achieved by ordinary people if they are serious about losing weight, even if they do not take white kidney bean extract.

Moreover, the European Food Safety Authority's scientific opinion on the weight loss effect of white kidney bean extract published in 2014 also pointed out that the existing evidence is insufficient to determine a causal relationship between white kidney bean extract and weight loss.

3. Don’t count on white kidney bean extract for weight loss

White kidney bean extract mainly acts on carbohydrates in starchy foods, and can only affect the carbon water absorption of starchy foods, such as rice, steamed bread, grains, and cakes. It is useless for foods high in sugar and fat, such as sugary drinks, milk, juice, fried foods, etc.

In addition, white kidney bean α-amylase inhibitor is a protein inhibitor. After being "baptized" by gastric acid after being eaten, its activity will be greatly reduced.

When it comes to losing weight, it is not just about controlling carbohydrates, but also keeping fat and protein within a reasonable range. If you don't control the total calories, it is useless to take white kidney bean extract just to inhibit the absorption of carbohydrates.

Some people may even eat more staple foods unscrupulously because they think they have this "magic weight loss tool", and end up getting fatter.

Summary: Don’t always think about taking shortcuts when losing weight. Shortcuts are often traps, and there may be nails in the traps.

One more reminder: Don’t dream of eating α-amylase inhibitor when cooking white kidney beans at home, because it is afraid of heat and loses its activity during cooking. Don’t eat white kidney beans raw either, as they contain phytohemagglutinin, which is toxic!

References:

[1] Jiang Caixia, Wang Rui, Zheng Xiqun, Zhang Shuo. Preparation and properties of α-amylase inhibitors from white kidney beans[J]. Food Science and Technology, 2022, 47(02): 251-255. DOI: 10.13684/j.cnki.spkj.2022.02.013.

[2] Chen Yikun, Li Qin, Zhao Jin, Chi Yongnan, Wang Minkang. Study on the weight loss effect of α-amylase inhibitor extracted from kidney bean on SD rats[J]. Food Science and Technology, 2012, 37(10): 207-210. DOI: 10.13684/j.cnki.spkj.2012.10.013.

[3]Xu Xiaofeng, Wu Xiangming, Shen Jianguo, Harry G Preuss. Evaluation of the weight loss effect of dietary supplements containing white kidney bean extract in overweight people[C]//. Abstracts of the 6th Annual Conference of the Chinese Society of Food Science and Technology and the 5th East-West Food Industry High-level Forum. [Publisher unknown], 2009: 27-28.