Researchers tested whether eating a Mediterranean diet and exercising together work better than doing either one alone. Two hundred people with belly fat and high triglycerides (a type of blood fat) followed different plans for 16 weeks: some ate Mediterranean food, some exercised, some did both, and some made no changes. The group that combined the Mediterranean diet with regular exercise had the best results for lowering their blood fat levels after eating. This suggests that combining healthy eating with physical activity may give you extra benefits that you wouldn’t get from just doing one or the other.

The Quick Take

  • What they studied: Whether eating a Mediterranean diet (lots of vegetables, fish, olive oil, and whole grains) combined with regular exercise works better than doing just one or neither for improving heart health markers, especially blood fat levels.
  • Who participated: Two hundred adults (average age 54, mostly women) who had extra belly fat and higher-than-normal triglycerides (blood fats). The study lasted 16 weeks.
  • Key finding: People who combined the Mediterranean diet with 150 minutes per week of moderate exercise had the lowest blood fat levels after eating a fatty meal. This combination appeared to work slightly better together than either approach alone, though the extra benefit was small.
  • What it means for you: If you’re trying to improve your heart health and blood fat levels, doing both—eating Mediterranean-style and exercising regularly—may give you better results than focusing on just one. However, both approaches alone still helped, so pick whichever fits your life best.

The Research Details

This was a carefully controlled experiment called a randomized controlled trial with a special 2x2 design. Researchers randomly divided 200 participants into four equal groups: one group made no changes (control), one group only changed their diet to Mediterranean style, one group only added exercise, and one group did both the diet and exercise together. This design lets researchers see if the combination works better than the individual parts.

The Mediterranean diet group received counseling and actual Mediterranean foods to help them stick with the plan. The exercise group aimed for 150 minutes per week of moderate-intensity activity (like brisk walking). The study lasted 16 weeks, and researchers measured blood fat levels before and after, including a special test where participants ate a fatty meal and researchers measured how their blood fats responded over 4 hours.

The study was very well-designed with an excellent completion rate—only 2.5% of people dropped out, which means the results are based on almost all the participants who started.

This study design is important because it’s one of the first to specifically test whether diet and exercise work better together (synergy) rather than just adding their individual effects. Previous research showed both help separately, but this study tested the combination in a controlled way. The 2x2 design is powerful because it lets researchers see the exact contribution of each component and whether they enhance each other.

This study has several strengths: it’s a randomized controlled trial (the gold standard for research), it had a very low dropout rate (2.5%), it used objective measurements of blood fats rather than just asking people questions, and it tested a real-world combination of interventions. The main limitation is that it only lasted 16 weeks, so we don’t know if benefits continue long-term. Also, most participants were women, so results might differ for men.

What the Results Show

The main finding was that people who combined the Mediterranean diet with regular exercise had the lowest blood fat levels (triglycerides) when measured 4 hours after eating a fatty meal. The combination showed a small synergistic effect, meaning it worked slightly better together than the individual parts would suggest.

When researchers looked at another blood fat marker called apolipoprotein B, they also saw a small synergistic effect from combining diet and exercise. However, this effect disappeared when they measured it again 48 hours after the intervention ended, suggesting the benefit might be short-lived.

All three intervention groups (diet only, exercise only, and diet plus exercise) showed improvements compared to the control group that made no changes. This confirms that both Mediterranean diet and exercise individually help reduce heart disease risk factors.

The study found that the Mediterranean diet alone and exercise alone each provided benefits for blood fat levels, though not as much as the combination. The fact that the synergistic effect on one marker (apolipoprotein B) disappeared after 48 hours suggests that maintaining the behaviors continuously is important for sustained benefits. The very high completion rate (97.5%) indicates that both the diet and exercise interventions were feasible for participants to follow.

Previous research has shown that both Mediterranean diet and regular exercise individually reduce heart disease risk. This study builds on that knowledge by testing whether combining them creates an extra benefit beyond what you’d expect from adding the two effects together. The findings suggest a small synergistic effect, which aligns with the theory that healthy eating and physical activity work through related but different mechanisms in the body.

The study only lasted 16 weeks, so we don’t know if the benefits continue for months or years. The sample was mostly women (75.5%), so results might be different for men. The synergistic effect was small, and one marker (apolipoprotein B) showed the benefit disappeared quickly after stopping the intervention. The study measured blood fats in a controlled lab setting after a fatty meal, which may not reflect real-world eating patterns. Finally, the study didn’t track whether people maintained these habits after the 16 weeks ended.

The Bottom Line

If you have high blood fats or belly fat, combining a Mediterranean diet with 150 minutes per week of moderate exercise appears to offer the best results for improving heart health markers. However, doing either one alone is still significantly better than doing nothing. Start with whichever feels more manageable for you, then add the other when you’re ready. The evidence suggests moderate confidence in this recommendation based on this single 16-week study.

This research is most relevant for adults with belly fat and elevated blood fats who want to reduce their heart disease risk. It’s also useful for anyone interested in the best approach to heart health through lifestyle changes. People without these risk factors may still benefit from these habits but should consult their doctor about personalized recommendations. This study doesn’t apply to children or people with certain medical conditions that require specialized diets.

You may see improvements in blood fat levels within weeks of starting these changes, based on this study’s 16-week timeframe. However, the benefits appear to require ongoing effort—one marker showed the benefit decreased within 48 hours of stopping. For lasting heart health improvements, these should become permanent lifestyle habits rather than temporary changes.

Want to Apply This Research?

  • Track weekly adherence to Mediterranean diet principles (servings of vegetables, fish, olive oil use) and weekly exercise minutes (aim for 150 minutes of moderate activity). Measure blood triglycerides every 4-8 weeks if possible through your doctor.
  • Start by adding one Mediterranean diet element per week (like olive oil, fish, or vegetables) while simultaneously scheduling three 50-minute exercise sessions weekly. Use the app to log meals and workouts together to reinforce the combined approach.
  • Create a dashboard showing both diet adherence and exercise minutes side-by-side to visualize the combination effect. Set weekly goals for both rather than focusing on one, and track how you feel (energy, digestion, fitness) alongside the numbers.

This research suggests potential benefits of combining Mediterranean diet and exercise for people with elevated blood fats, but it is not medical advice. Results are based on a 16-week study and may not apply to everyone. Before making significant dietary or exercise changes, especially if you have existing health conditions, take medications, or have high cholesterol or triglycerides, consult with your doctor or a registered dietitian. Individual results vary, and this study does not replace personalized medical guidance.