Researchers created a new tool to measure how well South Asians in America follow a diet that’s good for both their health and the environment. The diet, called the Planetary Health Diet, focuses on eating more plants and less meat. Scientists tested this tool on 891 South Asian adults and found it worked well. People who scored higher on this diet scale ate more vegetables, beans, and whole grains while eating less meat and animal products. The study shows this diet tool could help South Asian communities make healthier food choices that also help protect our planet.

The Quick Take

  • What they studied: Does a new diet scoring system work well for measuring how closely South Asian Americans follow a planet-friendly, healthy eating pattern?
  • Who participated: 891 South Asian adults (ages 40-84) living in Chicago and the San Francisco Bay Area who had no history of heart disease. Participants had grandparents from India, Pakistan, Nepal, Bangladesh, or Sri Lanka.
  • Key finding: The new diet score successfully measured healthy eating patterns in South Asian Americans. People with higher scores ate significantly more plant-based foods and less meat, and their diets created less environmental damage. The score was reliable and consistent.
  • What it means for you: If you’re South Asian or of South Asian descent, this new diet tool could help you track whether you’re eating in a way that benefits both your health and the environment. However, this study only tested whether the tool works—it didn’t yet prove that following this diet prevents disease.

The Research Details

Researchers created a new diet scoring system called the Planetary Health Diet Index (PHDI) based on guidelines from the EAT-Lancet Commission, which recommends eating patterns that are healthy for people and sustainable for Earth. They tested this scoring system on 891 South Asian adults who were part of a larger health study called MASALA. The researchers looked at what people ate using a detailed food questionnaire and gave each person a diet score based on 15 different food groups. The highest possible score was 140 points.

The study used several methods to check if the new scoring system actually worked. They compared the PHDI scores to other healthy eating scores that scientists already trust. They also looked at whether people with different health conditions (like diabetes) had different diet scores, and whether the score correctly showed that eating more plants meant eating less meat. They measured how consistent the scoring system was by checking if it gave similar results when measuring the same things multiple times.

This research matters because most diet-scoring tools were created for European or general American populations, not specifically for South Asians. South Asians have different traditional foods and eating patterns, so they need a tool designed for their culture. By creating a tool that works for South Asian communities, researchers can better help these populations understand if they’re eating in healthy and sustainable ways. This is especially important because South Asians living in America have higher rates of heart disease and diabetes.

The study has several strengths: it used a large sample of 891 people, it was specifically designed for South Asian populations, and it tested the tool in multiple ways to make sure it was accurate. The researchers used a detailed food questionnaire that was already proven to work well. However, the study only looked at one point in time (a snapshot), so it couldn’t prove that following this diet actually prevents disease. The internal consistency score (Cronbach’s alpha of 0.68) was acceptable but not extremely high, meaning the tool works but could potentially be improved.

What the Results Show

The new Planetary Health Diet Index successfully measured how well people followed the planet-friendly eating guidelines. Scores ranged from 51 to 119 out of a possible 140 points, with an average score of 89. This showed that most South Asian Americans in the study were following the diet recommendations to a moderate degree.

People with higher PHDI scores ate significantly more plant-based foods. Specifically, they consumed more vegetable protein, fiber, vitamin A, and vitamin C—all nutrients that come mainly from plants. At the same time, people with higher scores ate less meat and animal products, which meant they consumed less animal protein, cholesterol, and animal-based vitamin B12.

The study also found that the diet score was connected to real-world benefits. For every 5-point increase in the PHDI score, people’s overall healthy eating score improved significantly. Additionally, higher PHDI scores were linked to a 7% lower environmental footprint from their diet—meaning their food choices created less pollution and used fewer resources.

The study found interesting differences between groups of people. People who had graduated from college scored higher on the diet index than those without a bachelor’s degree. People with higher family incomes also had higher diet scores. Surprisingly, people with type 2 diabetes had higher PHDI scores than people with pre-diabetes or normal blood sugar levels, which suggests they may have made dietary changes after their diagnosis. Current smokers scored lower on the diet index than non-smokers, which aligns with other research showing that unhealthy habits often cluster together.

This is the first diet-scoring tool specifically created for South Asian populations based on the EAT-Lancet Planetary Health Diet guidelines. While other researchers have created similar tools for European and general American populations, those tools don’t account for the unique foods and eating patterns common in South Asian cultures. The PHDI showed very strong agreement with another well-established healthy eating score (the Alternative Healthy Eating Index), which suggests it’s measuring similar concepts of healthy eating. This validates that the new tool is measuring what it’s supposed to measure.

This study has several important limitations. First, it only looked at one point in time, so researchers couldn’t follow people over years to see if a higher diet score actually prevented heart disease or other health problems. Second, the study only included South Asian Americans in two cities (Chicago and San Francisco Bay Area), so the results might not apply to South Asians in other parts of the country or in other countries. Third, the study relied on people remembering what they ate, which can be inaccurate. Finally, the study couldn’t prove that the diet causes better health—only that higher scores are associated with eating more plants and less meat.

The Bottom Line

If you’re South Asian or of South Asian descent, this new diet tool could help you understand whether your eating patterns align with recommendations for both personal health and environmental sustainability. The evidence suggests that eating more plant-based foods and less meat is associated with better health markers. However, this study only validated that the tool works—it didn’t prove that following this diet prevents disease. Consider using this tool as one part of a broader approach to healthy eating, ideally with guidance from a registered dietitian who understands South Asian food culture. Confidence level: Moderate (the tool is reliable, but long-term health benefits haven’t been proven yet).

This research is most relevant for South Asian adults, especially those living in the United States who want to eat in a way that’s healthy for themselves and the planet. It’s particularly useful for people of South Asian descent with risk factors for heart disease or diabetes. Healthcare providers working with South Asian communities should find this tool helpful for counseling patients about diet. General readers interested in sustainable eating and environmental impact of food choices will also find this relevant. This research is less immediately applicable to people of other ethnic backgrounds, though the general principles about plant-based eating apply broadly.

The study didn’t measure how quickly people would see health benefits from following this diet. Based on other nutrition research, you might expect to see improvements in blood sugar control and cholesterol levels within 2-4 weeks of dietary changes, though more significant health improvements typically take several months. Weight changes, if applicable, usually become noticeable within 4-8 weeks. However, this particular study didn’t track these outcomes, so these are estimates based on general nutrition science.

Want to Apply This Research?

  • Track your daily intake of the 15 food components in the PHDI: whole grains, vegetables, fruits, legumes, nuts, seeds, fish, poultry, red meat, processed meat, eggs, dairy, added sugars, sodium, and saturated fats. Assign points based on how close you come to the recommended amounts each day, then calculate a weekly average score to see your progress toward a score of 140.
  • Start by identifying one plant-based food from your South Asian cuisine that you enjoy (such as dal, chickpea curry, or vegetable dishes) and commit to including it in at least one meal per day. Use the app to track this specific change and watch how it affects your overall PHDI score. Gradually add more plant-based meals while reducing portion sizes of meat-based dishes.
  • Calculate your PHDI score weekly by logging your food intake and tracking the 15 components. Set a goal to increase your score by 5 points per month. Create a visual chart showing your score progression over 3-6 months. Share your results with a healthcare provider or dietitian to get personalized feedback on your dietary changes and ensure you’re meeting nutritional needs while following the planetary health principles.

This research describes the development and testing of a new diet-scoring tool for South Asian populations. While the study validates that the tool accurately measures adherence to the Planetary Health Diet guidelines, it does not prove that following this diet prevents disease or improves health outcomes. This article is for educational purposes only and should not be considered medical advice. Before making significant dietary changes, especially if you have existing health conditions like diabetes, heart disease, or high cholesterol, consult with your healthcare provider or a registered dietitian. The findings apply specifically to South Asian adults and may not generalize to other populations. Individual nutritional needs vary based on age, sex, activity level, and medical history.