According to Gram Research analysis, your personality type and whether you’re naturally a morning person significantly predict whether you’ll eat an eco-friendly, plant-based diet. A 2026 study of 738 Italian adults found that women were 3 times more likely to eat sustainably, while people who are agreeable and open-minded were 43-60% more likely to choose plant-based foods. Surprisingly, very outgoing people and those high in honesty were less likely to eat eco-friendly diets, suggesting that different personality types may need different strategies to adopt sustainable eating habits.
A new study of 738 Italian adults reveals that your personality and whether you’re a morning person or night owl can predict whether you’ll choose an eco-friendly diet rich in plants. Researchers found that people who are more agreeable, open-minded, and prefer mornings are more likely to eat sustainably with fewer animal products. Interestingly, people who are very honest or very outgoing were less likely to adopt plant-based eating. The study suggests that understanding your natural personality traits and sleep preferences might help explain why some people find it easier to switch to environmentally friendly eating habits than others.
Key Statistics
A 2026 cross-sectional study of 738 Italian adults published in Frontiers in Nutrition found that only 19.78% of participants followed an eco-sustainable diet, while 80.22% reported eating a non-sustainable diet with significant animal products.
According to the 2026 study of 738 Italian adults, women were 3.05 times more likely to adopt an eco-sustainable diet compared to men, making gender one of the strongest predictors of plant-based eating.
A 2026 analysis of 738 Italian participants found that people scoring higher in Openness to Experience were 1.60 times more likely to eat eco-sustainably, while those high in Extraversion were 20% less likely to choose plant-based foods.
The 2026 study of 738 Italian adults revealed that morning-preference chronotype increased the likelihood of eco-sustainable eating by 1.08 times, suggesting that natural sleep schedules influence dietary choices.
The Quick Take
- What they studied: Whether your personality type and whether you’re naturally a morning person or night owl affects your likelihood of eating an eco-friendly diet with lots of plants and less meat.
- Who participated: 738 Italian adults answered detailed questions about their eating habits and completed personality and sleep-preference surveys. About 80% ate a typical diet with meat and animal products, while 20% followed a plant-based, eco-friendly diet.
- Key finding: Women were three times more likely to eat eco-friendly diets. Morning people, agreeable personalities, and open-minded people were significantly more likely to choose plant-based foods. Surprisingly, very outgoing people and those who score high on honesty were less likely to eat sustainably.
- What it means for you: Your natural personality traits and sleep schedule may influence how easy or hard it is for you to switch to a plant-based diet. This doesn’t mean you can’t change—it just means some people may need different strategies or motivation. Understanding your personality type might help you find the right approach that works for you.
The Research Details
Researchers surveyed 738 people in Italy about what they eat using a detailed food questionnaire that asked about their consumption of plant-based foods versus animal products. They also gave participants two personality tests: one measured whether people naturally prefer mornings or evenings (chronotype), and another measured six major personality traits including how agreeable, open-minded, honest, and outgoing people are. The researchers then used statistical analysis to see which personality traits and sleep preferences predicted whether someone ate an eco-friendly, plant-based diet.
This type of study is called cross-sectional, meaning researchers collected all the information at one point in time rather than following people over months or years. This approach is useful for identifying patterns and connections between personality traits and eating habits, but it can’t prove that personality causes dietary choices—only that they’re related.
Understanding the personality and biological factors that influence eating choices is important because it helps explain why some people naturally gravitate toward sustainable eating while others struggle with it. This knowledge could help nutritionists, health coaches, and app developers create personalized strategies that work with people’s natural tendencies rather than against them. If we know that open-minded, agreeable morning people are more likely to adopt plant-based eating, we can tailor messages and support to match different personality types.
This study surveyed a reasonably large sample of 738 people, which gives the findings more reliability than a small study. However, all participants were Italian, so results may not apply equally to other cultures with different food traditions and values. The study is cross-sectional, meaning it shows relationships between traits and eating habits but cannot prove that personality causes dietary choices. The researchers used validated, well-established personality and chronotype measurement tools, which strengthens confidence in the results. The study was published in a peer-reviewed nutrition journal, meaning other experts reviewed it before publication.
What the Results Show
The study found clear patterns in who adopts eco-sustainable diets. Women were significantly more likely to eat plant-based foods, with women being 3 times more likely than men to follow an eco-friendly diet. People who naturally prefer mornings showed a 1.08 times higher likelihood of eating sustainably for each point increase on the morning-preference scale. Two personality traits strongly predicted eco-friendly eating: Agreeableness (people who are cooperative and compassionate) increased the likelihood by 1.43 times, and Openness to Experience (people who are curious and open to new ideas) increased it by 1.60 times.
Surprisingly, some traits worked against sustainable eating. People who scored higher on Honesty-Humility were actually less likely to eat plant-based diets—their odds decreased by 31%. Similarly, more outgoing people (Extraversion) were 20% less likely to follow eco-friendly diets. Age also mattered slightly: each additional year of age was associated with a 2% decrease in the likelihood of eating sustainably.
Overall, only about 1 in 5 people in the study (19.78%) reported eating an eco-sustainable diet, while about 4 in 5 (80.22%) ate a typical diet that included significant amounts of animal products. This shows that plant-based eating remains uncommon in this Italian population, despite growing environmental awareness.
The research suggests that chronotype (morning versus evening preference) and personality traits work together to influence dietary choices. The study found that Agreeableness and Openness to Experience were the most helpful personality traits for adopting sustainable eating, while Honesty-Humility and Extraversion actually made it less likely. This suggests that people who are naturally curious, willing to try new things, and concerned about others’ wellbeing find it easier to switch to plant-based eating. In contrast, people who are very straightforward and honest, or very social and outgoing, may face more barriers to making this dietary shift.
This study adds to growing research showing that personality and biological factors influence food choices. Previous research has shown that personality affects many health behaviors, but this is one of the first studies to specifically examine how personality traits and sleep preferences predict eco-friendly eating. The finding that women are more likely to eat sustainably aligns with other research showing that women tend to be more concerned about environmental and health impacts of food. The connection between morning preference and sustainable eating is relatively novel and suggests that circadian rhythms (your body’s natural 24-hour cycle) may play a role in dietary choices, possibly through effects on decision-making and self-control.
The study has several important limitations. First, all participants were Italian, so results may not apply to people in other countries with different food cultures, values, and availability of plant-based options. Second, the study is cross-sectional, meaning it shows relationships but cannot prove that personality causes dietary choices—it’s possible that people who eat plant-based diets develop certain personality traits, or that a third factor influences both. Third, the study relied on people self-reporting their eating habits, which can be inaccurate because people may not remember exactly what they eat or may report what they think they should eat rather than what they actually eat. Finally, the study measured personality traits at one point in time, but personality can change somewhat over a person’s life, and eating habits can change too.
The Bottom Line
If you’re interested in adopting a more eco-friendly, plant-based diet, understanding your personality type and natural sleep preferences may help you find an approach that works for you. If you’re naturally open-minded and agreeable, you may find it easier to transition to plant-based eating by focusing on the ethical and environmental benefits. If you’re more outgoing or very honest-minded, you might need different motivation—perhaps focusing on health benefits, cost savings, or practical meal planning rather than environmental values. Morning people may find it easier to plan and prepare plant-based meals, while evening people might benefit from meal prep services or simpler recipes. These recommendations are based on moderate evidence from one study and should be combined with practical nutrition advice from a healthcare provider or registered dietitian.
Anyone interested in eating more sustainably or reducing their environmental impact through diet should find this research interesting. It’s particularly relevant for people trying to understand why they struggle with dietary changes, or for health coaches and nutritionists designing personalized nutrition programs. Parents might use these insights to understand their children’s food preferences. Environmental advocates and food companies could use this information to create more targeted messaging about sustainable eating. However, this research doesn’t apply equally to everyone—cultural food traditions, food availability, allergies, and economic factors are often more important than personality in determining what people eat.
If you decide to adopt a more plant-based diet based on your personality type, you shouldn’t expect overnight changes. Most nutrition research suggests that dietary habit changes take 2-4 weeks to feel natural, and 2-3 months to become established routines. Your personality traits are stable, so they’ll continue to influence your choices over time. If you’re naturally open-minded and agreeable, you might adapt more quickly. If you’re more outgoing or very honest, you may need to find different motivation strategies that align with your personality. Working with a nutritionist or using a food tracking app can help you stay consistent over the months needed to see health and environmental benefits.
Frequently Asked Questions
Does your personality type actually affect what you eat?
Research shows personality traits correlate with dietary choices. A 2026 study of 738 people found that open-minded, agreeable individuals were 43-60% more likely to eat plant-based diets, while outgoing people were 20% less likely. However, personality is just one factor—food availability, culture, and cost matter more for most people.
Are morning people more likely to eat healthy or sustainable diets?
Morning people showed a higher likelihood of eating eco-sustainable diets in a 2026 study of 738 Italian adults. Each point increase in morning preference increased sustainable eating likelihood by 8%. This may be because morning people have better planning and self-control for meal preparation.
Why would outgoing people be less likely to eat plant-based?
A 2026 study found outgoing people were 20% less likely to eat plant-based diets, possibly because social eating situations often center on meat-based meals, or because outgoing people prioritize social conformity over dietary principles. The research doesn’t explain the exact reason.
Can you change your eating habits if your personality doesn’t naturally support it?
Absolutely. Personality influences but doesn’t determine dietary choices. A 2026 study shows personality is just one factor among many. You can adopt sustainable eating through habit-building, finding motivation that matches your values, working with a nutritionist, or using tracking apps regardless of personality type.
What personality traits make it easiest to become vegetarian or vegan?
According to a 2026 study of 738 adults, Agreeableness (1.43 times more likely) and Openness to Experience (1.60 times more likely) most strongly predicted plant-based eating. These traits suggest curiosity about new foods and concern for others’ wellbeing support dietary change.
Want to Apply This Research?
- Track your plant-based meals and animal product consumption weekly, noting your mood and energy levels. Record whether you planned meals in the morning (for morning people) or evening (for night owls) to see which timing helps you stick to sustainable eating goals.
- Take a personality assessment within the app to identify your traits, then receive personalized meal suggestions and motivation strategies matched to your personality type. Morning people could get morning meal-planning reminders, while evening people could get evening prep suggestions. Open-minded users could explore new plant-based recipes weekly, while agreeable users could see the environmental and ethical impact of their food choices.
- Set up monthly check-ins to review your plant-based meal percentage and track changes in your eating patterns. Compare your personality profile to your actual eating habits to see if understanding your traits helps you make more sustainable choices. Use the app to identify which personality-matched strategies work best for you, then double down on those approaches.
This research shows associations between personality traits and eating habits, but does not prove that personality causes dietary choices. Results are from Italian adults and may not apply equally to other populations with different food cultures and availability. Individual dietary choices are influenced by many factors including health conditions, allergies, cultural traditions, economic circumstances, and personal values—not just personality. Before making significant dietary changes, especially if you have health conditions, consult with a registered dietitian or healthcare provider. This article is for informational purposes and should not replace professional medical or nutritional advice.
This research translation is published by Gram Research, the science division of Gram, an AI-powered nutrition tracking app.