New data from a Japanese study suggests that rice may play a role in promoting healthier diets and preventing non-communicable diseases (NCDs), contrasting with popular low-carbohydrate approaches to weight management.
“Maintaining appropriate weight and eating rice were positively associated with healthy diet scores in both sexes,” wrote researchers in Nutrients.
The link between eating rice and weight control
The study examined how dietary behaviours – including rice consumption, eating out, and home meal replacement use – relate to healthy diets and weight maintenance for NCD prevention among middle-aged Japanese, a group with rising obesity and NCD risk.
Researchers surveyed 577 participants (255 men and 322 women) aged 40–59 years in Hyogo Prefecture, Japan.
The study compared scores for healthy eating, weight management, rice consumption, eating out, and ready-to-eat foods across different sex and age groups, and examined whether these patterns differed between men and women at different ages.
“Results showed that maintaining an appropriate weight to prevent NCDs was associated with healthy diets composed of at least two balanced meals daily, eating breakfast regularly, and eating at least five vegetable-based dishes daily in both men and women,” researchers said.
They found that weight control for NCD prevention and rice consumption were linked to healthy diets.
“In Japan, the 2000 Japanese food-based dietary guidelines recommend a well-balanced diet consisting of a staple, main dish, and side dishes. Our findings on the positive effect of rice consumption frequency and healthy diets agreed with those of previous studies showing links between this traditional meal structure and consuming breakfast,” said researchers.
However, this does not support unrestricted rice consumption – balance is key as researchers point out the need to maintain appropriate intake of various food groups as recommended by the World Health Organization (WHO).
Rice as a regulator of balanced meals
Rice has long been a staple food across Asia, where it has shaped traditional eating patterns centred on balanced meals.
In Japan, this gave rise to washoku – a holistic approach that focuses on harmony in meal consumption.
A traditional washoku meal follows the ichijū-sansai (one soup, three sides) formula: steamed rice (gohan); miso soup (shiru); pickled vegetables (tsukemono); and three side dishes (okazu) – main course and side dishes that can include fish, meat, and vegetables.
This structure encourages more balanced meals that may support weight management, aligning with findings of a separate study that examined how a balanced diet can lead to better weight development.
Researchers note that these align with prior research findings that suggest people who regularly eat rice are more likely to follow balanced diets, including higher intake of vegetables and fibre as well as lower intake of fat.
Among Japanese consumers, eating rice especially at breakfast is also linked to more complete and balanced meals across the day.
Outside of Asia, a 10-year study from the United States reported that a high proportion of adults who consumed rice had better dietary quality than those who did not.
By contrast, habits such as eating out or consuming ready-to-eat meals are often associated with poorer diet quality.
Japan’s annual national survey data showed that people who frequently eat out or rely on ready-to-eat meals tend to consume well-balanced meals less often, with vegetables being the most commonly skipped component, said researchers.
Previous research on Hispanics and Latinos has also linked frequent eating out to poorer diet quality.
Global implications for the food industry and academia
While rice consumption, weight management behaviours, and reliance on eating out or ready-to-eat foods have each been linked to diet quality, few studies have examined them together.
This study therefore explored how these factors impact populations facing rising obesity and NCD risk.
“These findings suggest that rice may be widely considered a potential aid for sustainable healthy diets in the future, even in countries where rice is not the staple food,” said researchers.
However, they cautioned that further research is needed to clarify the link between rice consumption and weight management given the study limitations.
For example, the frequency of rice consumption was measured without distinguishing between white and brown rice. Since the WHO recommends increasing whole grain intake as part of a healthy diet, this distinction will be necessary in future research.
Longitudinal studies that track the same subjects over time should also be conducted to clarify whether maintaining an appropriate weight, along with associated behaviours such as rice consumption, leads to improvements in diet quality.
“In the future, policies should encourage the food service industry to promote healthy eating environments by offering low-salt meals with ample vegetables and fruits in addition to other efforts to support weight management to prevent NCDs,” researchers concluded.
“Furthermore, the causal relationship between maintaining an appropriate weight and healthy diets, including the potential role of eating rice, needs to be further investigated using nationwide longitudinal studies and research involving non-Japanese populations.”
Source: Nutrients
https://doi.org/10.3390/nu17193174
“Healthy Diets Are Associated with Weight Control in Middle-Aged Japanese”
Authors: Etsuko Kibayashi and Makiko Nakade