Researchers studied over 2,800 middle-aged and older adults in Spain to see how well they were following the Mediterranean diet, which is known to be healthy. While most people said they followed this diet pretty well, the study found some problems: most weren’t eating enough fruits, vegetables, and whole grains. Surprisingly, three-quarters of the group were overweight or obese, even though they claimed to follow a healthy diet. The study suggests that just saying you follow a healthy diet isn’t enough—people need to actually eat the right amounts of nutritious foods to stay at a healthy weight.

The Quick Take

  • What they studied: Whether Spanish adults were eating according to the Mediterranean diet (a diet with lots of vegetables, fruits, fish, and olive oil) and how their eating habits compared to official health recommendations.
  • Who participated: 2,833 middle-aged and older adults living in Spain who were representative of the general Spanish population. About 74% were overweight or obese, and most didn’t smoke.
  • Key finding: Although 88% of people said they followed the Mediterranean diet fairly well, most weren’t actually eating enough fruits, vegetables, and whole grains. Only 2% were eating the right amount of fat according to recommendations.
  • What it means for you: If you think you’re eating healthy because you follow a popular diet, you might still need to check if you’re actually eating enough of the right foods. It’s not enough to follow a diet in general—you need to eat the specific amounts of fruits, vegetables, and whole grains that experts recommend.

The Research Details

This was a cross-sectional study, which means researchers took a snapshot of what people were eating at one point in time, rather than following them over months or years. The researchers asked 2,833 Spanish adults to fill out a detailed food frequency questionnaire—basically a list of foods where people report how often they eat each item. The researchers then scored how well each person followed the Mediterranean diet using a special scoring system that goes from 0 to 55 points. They also measured people’s height, weight, and other health information to see if there were differences between people at different weights.

The researchers compared what people were actually eating to the official dietary guidelines from Spain’s food safety agency. This allowed them to see exactly where people’s diets fell short or exceeded recommendations. They looked at both the big picture (total carbohydrates, proteins, and fats) and specific foods (like how much fruit, vegetables, fish, and meat people ate).

This type of study is useful for understanding what’s happening in a real population at a specific moment in time, but it can’t prove that one diet causes weight gain or loss—it just shows what’s happening.

This research matters because it shows a disconnect between what people think they’re doing (following a healthy diet) and what they’re actually eating. By looking at a large, representative group of Spanish adults, the researchers could see real-world eating patterns, not just what people say they do. This helps health experts understand where education and support are needed most.

The study included a large number of people (2,833) who were representative of the Spanish population, which makes the findings more trustworthy. However, because this is a cross-sectional study, it only shows a snapshot in time and can’t prove cause-and-effect relationships. The study relied on people’s memory of what they ate (through questionnaires), which can sometimes be inaccurate. The researchers did measure actual physical characteristics like weight and height, which adds credibility to their findings.

What the Results Show

The most striking finding was that while 88% of participants reported medium-to-high adherence to the Mediterranean diet, their actual food intake didn’t always match this claim. When researchers looked at what people were actually eating compared to Spanish health recommendations, they found major gaps: 76% of people weren’t eating enough carbohydrates (they were getting only 35.4% of their calories from carbs when they should get more), and 73.5% weren’t eating enough protein.

The biggest problem was with fat intake: only 2% of people were eating the recommended amount of fat (less than 35% of calories). This might sound good, but it actually suggests people weren’t following the Mediterranean diet correctly, since that diet includes healthy fats from olive oil, nuts, and fish.

When the researchers looked at specific foods, they found that most people weren’t eating enough fruits, vegetables, whole grains, potatoes, and eggs. However, people were eating adequate amounts of legumes (beans), nuts, fish, seafood, and dairy products. Meat consumption was too high for most people—they were eating more than recommended.

Interestingly, the amount of calories and overall food patterns were similar whether people were at a healthy weight or overweight/obese. However, people with obesity ate fewer nuts, and people at healthy weights drank more red wine than those who were overweight.

The study found that Mediterranean diet scores (the measure of how well people followed the diet) were similar across all weight groups, averaging 34 points out of a possible 55. This was surprising because you might expect people at healthy weights to have higher scores. The fact that macronutrient intake (carbohydrates, proteins, fats, and fiber) was similar across weight groups suggests that weight differences might be related to total calories eaten rather than the types of foods chosen.

This research fits with other studies showing that many people in Mediterranean countries are moving away from traditional Mediterranean eating patterns. Previous research has shown that even in countries where the Mediterranean diet originated, younger and middle-aged adults are eating less of the traditional foods like vegetables and legumes. This study confirms that trend continues in older Spanish adults. The high rates of overweight and obesity despite claimed Mediterranean diet adherence align with other research showing that diet quality alone doesn’t guarantee healthy weight without attention to portion sizes.

This study has several important limitations. First, it’s cross-sectional, meaning it’s a snapshot at one moment—researchers can’t determine if poor eating habits caused weight gain or if weight gain led to different eating patterns. Second, the study relied on people’s memory of what they ate, which can be inaccurate. People might also report eating more healthily than they actually do (a bias called social desirability bias). Third, the study measured Mediterranean diet adherence using a scoring system, but this score didn’t match up with actual food intake in some cases, suggesting the scoring system might not perfectly capture real eating patterns. Finally, the study didn’t measure total calorie intake, which is important for understanding weight gain.

The Bottom Line

If you want to follow the Mediterranean diet and maintain a healthy weight, focus on eating the specific recommended amounts of foods, not just following the diet in general. Eat more fruits, vegetables, and whole grains—these are areas where most people fall short. Make sure you’re eating enough protein and getting healthy fats from sources like olive oil, nuts, and fish. Reduce meat consumption, especially red meat. These recommendations have moderate-to-strong evidence supporting them for overall health and weight management.

Anyone interested in the Mediterranean diet should pay attention to these findings, especially middle-aged and older adults. If you’ve been assuming that following a popular diet automatically means you’re eating well, this research suggests you should double-check your actual food intake. People trying to lose weight or maintain a healthy weight should be particularly interested, since the study shows that diet adherence scores alone don’t guarantee healthy weight. Healthcare providers should also note these findings when counseling patients about diet.

Changes in eating habits typically take 2-4 weeks to become routine, but health benefits like improved energy and digestion may appear within 1-2 weeks. Weight changes, if they occur, usually take 4-8 weeks to become noticeable. Long-term health benefits like improved heart health and reduced disease risk develop over months to years of consistent eating patterns.

Want to Apply This Research?

  • Track daily servings of fruits, vegetables, whole grains, nuts, and fish. Set specific goals like ‘2 servings of vegetables at lunch and dinner’ and ‘1 serving of nuts as a snack’ rather than just tracking general diet adherence. Use the app to log actual portion sizes, not just food types.
  • Instead of just marking ‘followed Mediterranean diet today,’ use the app to log specific foods and amounts. For example, log ‘1 cup broccoli,’ ‘1 apple,’ ‘1 ounce almonds,’ and ‘4 ounces salmon.’ This concrete tracking helps you see if you’re actually meeting recommendations, not just following the diet in general.
  • Weekly review: Check if you met your targets for fruits, vegetables, whole grains, nuts, and fish. Monthly review: Look at patterns in which food groups you consistently miss. Quarterly review: Compare your food logs to official recommendations to see if your actual intake matches your perception of your diet. This helps catch the gap between what you think you’re eating and what you’re actually eating.

This research describes eating patterns in a Spanish population and should not be interpreted as medical advice. Individual nutritional needs vary based on age, health conditions, medications, and activity level. Before making significant changes to your diet, especially if you have existing health conditions like diabetes, heart disease, or are taking medications, consult with your healthcare provider or a registered dietitian. This study shows associations between diet and weight but does not prove that changing your diet will cause weight loss or improve health outcomes in all individuals. Results from Spanish adults may not apply equally to other populations.