If you’re on a mission to level up your nutrition and boost longevity, you’ve likely come across the Mediterranean diet. However, recent research published in Nature Medicine has revealed that there may be an even better eating plan deserving of your consideration: the Alternative Healthy Eating Index (AHEI).

The AHEI is a scoring system developed by Harvard University, the University of Copenhagen, and the University of Montreal to assess diet quality based on foods and nutrients predictive of chronic disease risk. It emphasizes whole grains, fruits, vegetables, nuts, legumes, and healthy fats, while minimizing red and processed meats, sugar-sweetened beverages, and trans fats. 

“The AHEI is a shift from ‘are you eating enough fruits?’ to ‘are you eating in a way that predicts better health outcomes?’” says Kristen Lorenz, RD, a registered dietitian who specializes in longevity and metabolic health. “Think of it as a precision tool for diet quality, rather than just a checklist.”

The latest 30-year study analyzed the diets of 105,000 adults who answered questions about their eating habits between the ages of 39 and 69. Researchers then examined eight dietary patterns, factoring in the participants’ consumption of fruits, vegetables, whole grains, unsaturated fats, nuts, legumes, fish, poultry, dairy, and processed snacks. 

Of those studied, just one in 10 aged in a “healthy way,” which the study defined as reaching 70 years old without major chronic disease, as well as having good cognitive functioning, strong mental health, and the physical ability to move freely. Furthermore, those healthy agers all had one thing in common: a diet rich in plant-based foods and low in highly processed foods, with a moderate intake of animal-based products. 

Given the potential of this eating plan to promote longevity, the AHEI was developed as the gold standard. Here’s everything you need to know. 

What is the AHEI diet?

The AHEI actually isn’t a diet, says Sarah Rueven, RDN, a registered dietitian and founder of Rooted Wellness. Rather, it’s an index that assigns ratings to foods linked to lowering your risk of chronic diseases such as cancer, heart disease, and diabetes, she explains. 

More specifically, the AHEI diet emphasizes four central tenets:

• A high intake of vegetables, fruits, whole grains (like oatmeal, brown rice, and quinoa), nuts, and legumes (like beans and peas) 
• A high intake of healthy fats, particularly from unsaturated sources (like avocado, olive oil, seeds, and fish)
• Moderate alcohol consumption 
• Limited intake of red and processed meat, sugar-sweetened beverages (like soda and flavored coffee), sodium, and trans fat (like baked goods, fried foods, and vegetable oils)

As for quantity, the AHEI suggests aiming for five servings of vegetables a day, four servings of fruit, five to six servings of whole grains, and at least one serving each day of nuts, legumes, and vegetable protein (such as edamame, lentils, asparagus, and sweet corn), says Lauren Benser, RD, a registered dietitian and founder of Lauren Benser Nutrition.

That said, the main goal of the AHEI is to prioritize quality over quantity, Lorenz says. “It encourages sustainable, long-term eating habits, and values what you eat most often, not just what you occasionally add to your plate.” 

Benefits of the AHEI diet 

At its core, the AHEI prioritizes the prevention of chronic disease. “It’s a proactive, evidence-based strategy that emphasizes whole, nutrient-rich foods to support overall health, so it’s not just for those ‘at risk,’” Lorenz says. “It’s a prevention-first playbook for everyone.”

A primarily plant-based diet may help you live longer by lowering the risk of chronic disease, thanks to the high fiber, antioxidants, and anti-inflammatory compounds, according to the American College of Lifestyle Medicine. Plant foods and healthy fats also support a healthy gut, protect cells from oxidative stress (which leads to cell and tissue damage), and promote weight management. 

Additionally, those who consume a plethora of whole, plant-based foods experience reduced inflammation in the body, which research suggests can ultimately enhance cognitive function and overall brain health, especially as one ages.

On the flip side, ultra-processed foods are associated with cardiovascular disease, type 2 diabetes, mental health disorders, certain cancers, and premature death. Excessive alcohol consumption weakens your immune system, making your body a much easier target for physical and mental illness. 

So, because the AHEI diet is designed to prioritize nutrient-dense foods and minimize processed and alcoholic counterparts, Rueven says it’s a long-term eating habit that can boost longevity, support healthy aging, and decrease the risk of adverse health outcomes. 

How is the AHEI diet different from the Mediterranean diet and Healthy Eating Index?

The latest study found that the AHEI diet was best for healthy aging. However, there are certainly parallels to the Mediterranean diet. Both eating plans emphasize plant-based foods and healthy fats, with minimal red meat, sodium, and processed foods. The AHEI provides a structured scoring system to assess diet quality based on specific components linked to disease risk, Lorenz says. “AHEI is like a clinical measuring tape, whereas the Mediterranean diet is more like a guiding philosophy.”

The AHEI also differs from the USDA’s Healthy Eating Index (HEI), which is a measure of diet quality used to assess how well a set of foods aligns with key recommendations and dietary patterns published in the Dietary Guidelines for Americans. The AHEI offers a targeted approach to dietary components with strong evidence linking them to chronic disease prevention, whereas the HEI measures compliance with the dietary guidelines and may not reflect the latest research on disease prevention, Rueven explains.

As for other healthy eating patterns, the study also explored the following: 

• Dietary Approaches to Stop Hypertension (DASH): An eating plan designed to prevent or treat high blood pressure, with a focus on fruits, vegetables, whole grains, lean protein, and minimal sodium.
• Mediterranean-DASH Intervention for Neurodegenerative Delay (MIND): An eating plan designed to lower the risk of dementia, focusing on whole grains, green leafy vegetables, berries, nuts, beans, fish, and poultry.
• Healthful plant-based diet (hPDI): A balanced eating plan that focuses on fruits, vegetables, whole grains, legumes, and nuts.
• Planetary Health Diet Index (PHDI): A sustainable diet rich in fruits, vegetables, whole grains, nuts, and legumes, while minimizing red meat, processed meat, and eggs. 
• Empirically inflammatory dietary pattern (EDIP): A food-based index that explores inflammatory markers of processed meat, red meat, fish, vegetables, refined grains, and tomatoes.
• Empirical dietary index for hyperinsulinemia (EDIH): A dietary score that analyzes food to predict insulin secretion and blood sugar management.

All told, Benser says the AHEI confirms that eating well significantly impacts your ability to age healthfully. Lorenz agrees, noting that healthy aging isn’t simply luck. “It’s a series of lifestyle choices, and the AHEI is part of that blueprint.”