Gram Research analysis of 617 Spanish teenagers found that eating more plant-based protein instead of animal protein was associated with significantly higher quality of life and well-being scores. Teens who swapped chicken and red meat for beans, lentils, and nuts reported better overall happiness and health satisfaction, with the strongest benefits coming from replacing poultry and red meat with plant sources. While this connection is clear, the study doesn’t prove that changing protein sources causes better well-being—it shows they’re linked.
A new study of 617 Spanish teenagers found that eating more plant-based protein instead of animal protein was connected to better overall quality of life and mental well-being. Researchers looked at what teens ate and measured their happiness and health using a special survey. The teens who swapped chicken and red meat for beans, lentils, and nuts reported feeling better about their lives. While this doesn’t prove that changing protein sources will make you happier, it suggests that the types of protein we choose might matter for how we feel, not just our bodies.
Key Statistics
A 2026 cross-sectional study of 617 Spanish adolescents found that isocaloric substitution of plant-based protein for animal-based protein was associated with 0.37 standard deviation units higher quality-of-life scores, a meaningful improvement on measures of adolescent well-being.
Among 617 teenagers studied in 2021-2022, replacing poultry with plant-based protein showed the strongest association with better quality of life (0.44 units higher), while replacing red meat with plant protein also showed significant benefits (0.43 units higher).
A 2026 study of Spanish adolescents found that eating animal protein from legumes and nuts instead of other animal sources was associated with substantially higher quality-of-life scores (0.64 and 0.56 units higher, respectively), suggesting these plant proteins may be particularly beneficial for teen well-being.
Research from 617 Spanish teenagers aged 12-17 showed that the association between plant protein and better quality of life remained significant even after accounting for physical activity, sleep duration, and sedentary behavior, indicating the protein source itself has an independent effect on well-being.
The Quick Take
- What they studied: Whether eating plant-based proteins instead of animal proteins affects how happy and healthy teenagers feel overall
- Who participated: 617 Spanish teenagers between ages 12-17 (57% girls), with an average age of 14 years, studied during 2021-2022
- Key finding: Teens who ate more plant protein instead of animal protein scored significantly higher on quality-of-life measures—about 0.37 points higher on a scale where bigger numbers mean better well-being
- What it means for you: Swapping some chicken or beef for beans, lentils, and nuts might help you feel better overall, though this study shows a connection, not proof of cause-and-effect. Talk to a doctor or nutritionist before making big diet changes
The Research Details
Researchers collected information from 617 teenagers in Murcia, Spain about everything they ate over a period of time. They used a special computer method called ‘isocaloric substitution analysis’ that lets them see what happens when you swap one food for another while keeping the total calories the same. This approach helps isolate the effect of the protein source itself, rather than just eating more or fewer calories overall.
The teenagers also completed a quality-of-life survey called KIDSCREEN-10, which asks about their happiness, energy, relationships, and how they feel about school and life in general. The researchers then looked at whether the teens who ate more plant protein had higher quality-of-life scores than those who ate more animal protein.
The study accounted for other important factors that might affect how teens feel, including their age, sex, weight, family income level, how much they sleep, how much they exercise, and how much time they spend sitting down. This helps make sure the connection between protein type and well-being is real and not just due to other lifestyle differences.
This research approach is important because it looks at real eating patterns in real teenagers’ lives, not just what happens in a lab. By using the substitution method, scientists can see the specific effect of choosing plant protein over animal protein, which is more useful than just comparing vegetarians to meat-eaters (since those groups differ in many other ways too). Understanding how food choices affect mental health and quality of life in teenagers is especially valuable because these are important years for developing healthy habits.
This study has several strengths: it included a fairly large group of teenagers (617), it measured quality of life with a validated survey tool, and it controlled for many other factors that could influence the results. However, because it’s a cross-sectional study (a snapshot in time rather than following people over months or years), we can’t be sure that eating plant protein actually causes better quality of life—it could be that teens who feel better are more likely to eat healthier. The study also only included Spanish teenagers, so results might differ in other countries with different food cultures and access to plant-based proteins.
What the Results Show
The main finding was clear: when researchers compared teens who ate more plant-based protein to those who ate more animal-based protein (keeping calories equal), the plant-protein group had significantly higher quality-of-life scores. The difference was about 0.37 standard deviation units, which is a meaningful improvement on the 0-100 point scale used to measure well-being.
When researchers looked at specific food swaps, the strongest benefits came from replacing poultry (chicken) with plant proteins (0.44 units higher) and replacing red meat with plant proteins (0.43 units higher). This suggests that the type of animal protein matters—swapping chicken or beef for beans and nuts had the biggest positive effect.
Interestingly, the opposite was also true: when teens ate more animal protein instead of plant protein from legumes like beans and lentils (0.64 units lower) or nuts (0.56 units lower), their quality-of-life scores were noticeably lower. This suggests that legumes and nuts might be particularly beneficial for teen well-being.
The study found that the benefits of plant protein were consistent across different age groups and both boys and girls, suggesting this pattern isn’t limited to just one type of teenager. The researchers also noted that these associations remained strong even after accounting for other healthy behaviors like exercise and sleep, indicating that the protein source itself appears to have an independent effect on quality of life.
Previous research has shown that overall diet quality affects how teenagers feel and their mental health, but this is one of the first studies to look specifically at swapping one type of protein for another. According to Gram Research analysis, this finding adds to growing evidence that plant-based proteins offer benefits beyond just being lower in saturated fat—they may also support better mental health and well-being in young people. The results align with studies in adults showing that plant-forward diets are associated with better mood and life satisfaction.
The biggest limitation is that this study shows a connection between plant protein and better quality of life, but doesn’t prove that eating plant protein causes better quality of life. Teens who feel better might naturally choose healthier foods, or other unmeasured factors could explain both the food choices and the well-being. The study only included teenagers in one region of Spain, so results might not apply to teens in other countries with different food availability and cultural eating patterns. Additionally, the study relied on teenagers reporting what they ate, which can be inaccurate. Finally, the study was conducted during 2021-2022, which included pandemic-related disruptions that might have affected both eating patterns and mental health.
The Bottom Line
Based on this research, teenagers might consider including more plant-based proteins like beans, lentils, nuts, and seeds in their diet, particularly as replacements for red meat and poultry. This change appears to be associated with better overall quality of life and well-being. However, this is not a strong recommendation to eliminate animal protein entirely—the study shows benefits from substitution, not elimination. Confidence level: Moderate. The evidence suggests a real connection, but more research is needed to prove cause-and-effect.
This research is most relevant to teenagers and their parents or guardians who want to support better mental health and well-being through diet. It’s also useful for school nutritionists and health educators. Teenagers with allergies to nuts or legumes should work with a healthcare provider to find alternative plant proteins. Those with certain medical conditions should consult their doctor before making significant dietary changes.
If a teenager started eating more plant-based proteins, they might notice improvements in how they feel within a few weeks to a few months, though this study doesn’t specify how quickly benefits appear. The quality-of-life improvements measured in this study represent overall patterns, so consistency matters more than perfection. This isn’t a quick fix—it’s part of building long-term healthy eating habits.
Frequently Asked Questions
Does eating plant-based protein actually make teenagers happier?
Research shows a strong connection between eating more plant protein and better quality of life in teenagers, but this study can’t prove it causes happiness. Teens who feel better might naturally choose healthier foods. More long-term studies are needed to confirm cause-and-effect.
What plant proteins should teenagers eat for better mental health?
Beans, lentils, nuts, and seeds showed the strongest benefits in this study. The research suggests replacing some chicken and red meat with these plant sources may support better well-being. Start with one plant protein per day and gradually increase.
Do teenagers need to give up meat to see benefits from plant protein?
No. This study shows benefits from substituting some animal protein with plant protein, not eliminating meat entirely. Swapping one or two meals per week from meat to plant-based sources appears to be associated with improved quality of life.
How quickly will a teenager feel better after eating more plant protein?
This study doesn’t specify how quickly improvements appear. Quality-of-life changes likely develop over weeks to months as part of overall healthy eating habits. Consistency matters more than immediate results.
Does this research apply to all teenagers or just Spanish ones?
This study included only Spanish teenagers, so results might differ in other countries with different food cultures and access to plant-based proteins. More research in diverse populations is needed to confirm these findings apply broadly.
Want to Apply This Research?
- Track daily plant-based protein servings (beans, lentils, nuts, seeds, tofu) and animal protein servings separately. Set a goal to gradually increase plant protein to 50% of total protein intake over 4-8 weeks, then monitor weekly quality-of-life check-ins using a simple 1-10 happiness scale.
- Start by adding one plant-based protein source to meals you already eat: sprinkle nuts on breakfast cereal, add beans to lunch salads, or swap ground beef for lentils in tacos one day per week. Use the app to log these swaps and celebrate small wins to build momentum.
- Use the app to track protein sources weekly and correlate with a simple mood/energy log. After 4 weeks, review whether weeks with higher plant protein intake correspond with higher well-being scores. Adjust gradually based on what you notice, aiming for sustainable changes rather than dramatic overhauls.
This research shows an association between plant-based protein and better quality of life in teenagers, but does not prove cause-and-effect. Individual results may vary based on overall diet, lifestyle, and health status. Teenagers should consult with a doctor, registered dietitian, or nutritionist before making significant dietary changes, especially those with food allergies, medical conditions, or taking medications. This article is for educational purposes and should not replace professional medical advice. The study was conducted in Spain and may not apply to all populations.
This research translation is published by Gram Research, the science division of Gram, an AI-powered nutrition tracking app.