Researchers in Japan studied nearly 500 adults to see if following their country’s food guide (called the Spinning Top) helped people eat more nutritious foods. They found that people who followed the guide more closely did eat foods with better nutrition. However, the guide didn’t necessarily help people save money or reduce their environmental impact through food choices. The study suggests that while the food guide works well for nutrition, it might need updates to also consider cost and climate effects of different foods.

The Quick Take

  • What they studied: Whether following Japan’s official food guide (the Spinning Top) helps people eat more nutritious foods, and whether it affects food costs and environmental impact
  • Who participated: 479 adults aged 30-65 years living in Saitama Prefecture, Japan (206 men and 273 women) who kept detailed food diaries for two days
  • Key finding: People who followed the food guide more closely ate foods with better nutritional value. However, following the guide didn’t automatically mean lower food costs or less environmental impact from their food choices
  • What it means for you: The Japanese food guide appears to work well for helping people eat more nutritious foods. However, if you’re also concerned about saving money or reducing your environmental footprint through food choices, you may need to make additional, specific food decisions beyond just following the basic guidelines

The Research Details

This was a cross-sectional study, which means researchers looked at a snapshot of people’s eating habits at one point in time rather than following them over months or years. Participants completed a questionnaire and kept detailed records of everything they ate for two days. Researchers then scored how well each person followed Japan’s official food guide (the Spinning Top), which recommends eating from different food groups in balanced amounts. They also calculated how nutritious each person’s diet was, how much greenhouse gas their food choices produced, and how much they spent on food. The researchers used statistical analysis to look for connections between following the food guide and these other factors.

This approach is useful because it shows real-world eating patterns and allows researchers to examine multiple outcomes (nutrition, cost, and environmental impact) at the same time. However, because it’s a snapshot rather than following people over time, we can’t be completely sure about cause-and-effect relationships.

The study used actual food diaries rather than relying only on memory, which is more accurate. Researchers excluded people whose reported food intake seemed unrealistic, which improves data quality. The sample size of 479 people is reasonable for this type of study. However, the study only looked at people in one region of Japan, so results may not apply to other areas or countries with different food systems and cultures.

What the Results Show

People who followed Japan’s food guide more closely had better nutrition in their diets—this was true for both men and women. The researchers created a modified version of the food guide score that also considered the balance between white meat (like chicken) and red meat (like beef). Both the original and modified scores showed the same positive relationship with nutrition quality.

However, the results differed between men and women when looking at cost and environmental impact. In men, following the food guide had no significant connection to either food costs or greenhouse gas emissions from their diet. In women, following the guide was associated with higher food costs and higher greenhouse gas emissions—meaning their diets had a larger environmental footprint.

When researchers adjusted their analysis to account for total calories eaten, the connections between following the food guide and both cost and environmental impact disappeared. This suggests that the total amount of food people eat may be more important than which specific foods they choose when it comes to cost and environmental impact.

The modified food guide score that specifically tracked the ratio of white to red meat showed a slightly weaker connection to greenhouse gas emissions compared to the original score. This suggests that simply adjusting the balance between types of meat doesn’t substantially reduce the environmental impact of following the guide. The researchers noted that more detailed attention to specific food choices—beyond just following the basic food groups—would be needed to address both cost and climate concerns.

This study adds to existing research showing that food-based dietary guidelines generally improve nutrition quality. The finding that following guidelines doesn’t automatically reduce cost or environmental impact aligns with other research suggesting that nutritious eating and sustainable eating require different strategies. The gender differences found here (where the associations appeared in women but not men) are interesting and suggest that men and women may respond differently to dietary guidelines, though more research is needed to understand why.

The study only included people from one region of Japan, so results may not apply to other parts of Japan or other countries. The food diaries only covered two days, which may not represent typical eating patterns throughout the year. The study is cross-sectional, meaning researchers can’t determine whether following the food guide causes better nutrition or whether people who already eat well are more likely to follow the guide. The study didn’t examine why women showed different patterns than men. Finally, the study didn’t look at specific foods in detail, only broad food groups, which limits understanding of which particular foods drive the results.

The Bottom Line

If your goal is to improve nutrition, following Japan’s food guide (or similar food-based guidelines in your country) appears to be effective and is recommended with moderate confidence. If you also want to reduce food costs or environmental impact, you’ll need to make additional, specific choices about which foods to buy—the basic food guide alone may not be enough. Consider consulting with a nutritionist or dietitian for personalized advice on balancing nutrition, cost, and environmental concerns.

This research is most relevant to people in Japan or those following Japanese dietary guidelines. Adults aged 30-65 who want to improve their nutrition should find this helpful. People concerned about both nutrition and environmental sustainability should note that they may need strategies beyond basic food guidelines. This research is less directly applicable to people in other countries with different food systems, though the general principles may have some relevance.

If you start following a food guide more closely, you should expect to see improvements in your overall nutrition within a few weeks as your body adjusts to the new eating pattern. However, changes in body composition, energy levels, or other health markers may take 4-12 weeks to become noticeable. Environmental and cost impacts would depend on your specific food choices and would be measurable immediately through tracking spending and carbon footprint.

Want to Apply This Research?

  • Track daily adherence to food groups (grains, vegetables, fruits, protein, dairy) using a simple checklist. Score yourself 0-10 daily based on how well you followed the food guide recommendations. Also track weekly food spending and estimate carbon footprint using a food carbon calculator app.
  • Start by identifying which food groups you’re currently missing or under-consuming. Pick one group to focus on each week (for example, ‘Week 1: Add one extra serving of vegetables daily’). Use the app to log meals and get real-time feedback on whether you’re meeting food group targets.
  • Weekly review: Check your food guide adherence score, spending, and estimated carbon footprint. Monthly review: Assess whether nutrition has improved (using app-calculated nutrient scores if available), whether costs have changed, and whether you’re meeting your environmental goals. Adjust specific food choices monthly based on which areas need improvement.

This research describes associations between following dietary guidelines and nutrition, cost, and environmental outcomes in a specific population in Japan. These findings should not be considered medical advice. Individual nutritional needs vary based on age, health status, activity level, and medical conditions. Before making significant changes to your diet, consult with a healthcare provider, registered dietitian, or nutritionist, especially if you have existing health conditions, take medications, or have dietary restrictions. This study shows correlation, not causation, and results may not apply to populations outside of Japan or different demographic groups.