Sunday, May 5, 2019

Japanese Study Suggests Eating More Rice Can Help Fight Obesity

Obesity is claimed to be a global epidemic. Definitely, it is on the rise. However, some countries are not facing the same challenge. 

According to the Center for Disease Control and Prevention, 39.8% of people in the United States now have obesity. In contrast, the figure in Japan is only 4.3%, say the World Health Organization. 

The array of factors that could be involved in differences such as this are manifold – so where would one begin? 

According to one group of researchers, a good place to start might be rice. 

Researchers from Doshisha Women's College of Liberal Arts in Kyoto, Japan, decided to take a closer look. And they presented their findings at the European Congress on Obesity (ECO2019) in Glasgow, Scotland. 

To investigate, the scientists took data from 136 countries. They found that countries where people ate an average of at least 150g of rice per day had significantly lower rates of obesity than countries where people ate less than the global average amount of rice, around 14g per day. 

The researchers attempted to take into account as many confounding variables as they could, including average education level, smoking rates, total calories consumed, money spent on healthcare, percentage of the population over 65, and gross domestic product per capita. 

All of these variables were significantly lower in the countries whose residents ate the most rice; however, even after accounting for this in their analysis, the researchers found that the positive influence of rice over obesity persisted. 

From their data, they estimate that an increase of just one-quarter of a cup of rice per day (50g per person) could reduce global obesity by 1%. 

Lead researcher Professor Tomoko Imai (left) says: “The observed associations suggest that the obesity rate is low in countries that eat rice as a staple food. Therefore, a Japanese food or an Asian-food-style diet based on rice may help prevent obesity”. 

When considering exactly why rice might influence obesity rates, Prof. Imai says: "Eating rice seems to protect against weight gain. It's possible that the fiber, nutrients, and plant compounds found in whole grains may increase feelings of fullness and prevent overeating". 

She adds, "Rice is also low in fat and has a relatively low postprandial blood glucose level, which suppresses insulin secretion". 

But research limitations should be noted. 

The researchers know that distinguishing between cause and effect is incredibly challenging when looking at diet – particularly on such a large scale. Though they accounted for as many confounding variables as possible, it is still likely that they did not consider many other important factors in the analysis. 

Furthermore, they did not consider the type of rice that a population tends to consume, which could be important. 

In fact, a meta-analysis published in the BMJ in 2012 looked at the relationship between white rice and the risk of type 2 diabetes. 

Its authors concluded that: "Higher consumption of white rice is associated with a significantly increased risk of type 2 diabetes, especially in Asian (Chinese and Japanese) populations”. 

Another study that involved more than 10,000 Korean adults found that a diet centered on white rice was associated with obesity. 

Doubts persist, so scientists should continue to study the impact of rice on obesity. If such a cheap, readily available food as rice could play even a small part in the fight against obesity, it is worth pursuing. However, for now, the jury is out.

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