Researchers are testing whether eating more plant-based foods rich in natural compounds called polyphenols works better than taking supplements for weight loss and heart health. In this 12-week study, 99 adults with extra weight will be split into three groups: one eating a plant-based diet, one taking polyphenol supplements while eating normally, and one eating a regular healthy diet. Scientists will measure weight loss, heart health markers, and changes in gut bacteria to see which approach works best. This research could help doctors recommend the most effective way to improve health through diet.

The Quick Take

  • What they studied: Whether eating a plant-based diet full of natural plant compounds works better than taking supplements of those same compounds for losing weight and improving heart health
  • Who participated: 99 adults aged 25-45 years old from Chile who are overweight or have obesity and have risk factors for heart disease
  • Key finding: This is a study protocol (a plan for research), not yet completed results. The study will compare three groups over 12 weeks to see which approach—eating plant foods, taking supplements, or eating a regular healthy diet—helps most with weight loss and heart health
  • What it means for you: If results show plant-based foods work better than supplements, it suggests eating whole foods might be more effective than taking pills. However, wait for the actual results before changing your diet, as this is just the research plan

The Research Details

This is a randomized controlled trial, which is one of the strongest types of research studies. Researchers will randomly assign 99 people into three equal groups. All groups will eat fewer calories to lose weight, but one group will eat lots of plant-based foods, another will take polyphenol supplements (natural compounds from plants), and the third will take a placebo (fake pill). By randomly assigning people, researchers can fairly compare the groups.

The study lasts 12 weeks and takes place in Chile. Researchers chose this design because it allows them to see if the plant-based foods themselves are special, or if the supplements work just as well. They’re specifically looking at compounds called polyphenols, which are found naturally in foods like berries, apples, nuts, and olive oil.

Participants will have their weight, blood pressure, heart health markers, and gut bacteria measured at the start and end. Researchers will also track what people eat using special software and measure physical activity with devices worn on the body.

This research design is important because it answers a practical question: should people eat more plant foods or take supplements? Many people wonder if they can get the same benefits from a pill as from eating healthy food. This study will provide real evidence by comparing both approaches fairly. Understanding how plant compounds affect weight loss and heart health could help millions of people make better health choices.

This study has several strengths: it’s randomized (fair assignment to groups), it includes a placebo control (so researchers can rule out the placebo effect), and it measures multiple health markers, not just weight. The researchers are using advanced technology to measure blood compounds and gut bacteria changes. However, this is a relatively small study (99 people) and only lasts 12 weeks, so results may not apply to everyone or show long-term effects. The study is being conducted in Chile, so results might differ in other countries with different foods available.

What the Results Show

This document is a study protocol, meaning it describes the plan for the research but does not yet contain actual results. The study is designed to measure body weight as the main outcome after 12 weeks of intervention. The researchers will compare how much weight each group loses and use statistical tests to determine if differences between groups are meaningful or just due to chance.

The study will also measure several heart health factors including blood pressure, cholesterol-related compounds, and markers of inflammation. These measurements will help researchers understand whether the polyphenol compounds (from either food or supplements) provide additional benefits beyond simple weight loss.

One unique aspect of this study is that researchers will analyze changes in gut bacteria and special compounds produced by those bacteria. This is important because growing evidence suggests that gut bacteria play a role in weight management and heart health. By measuring these changes, researchers can understand the biological mechanisms—the ‘how’ and ‘why’—behind any weight loss or health improvements.

Beyond weight loss, the study will examine how each approach affects cardiovascular risk factors like blood pressure and blood sugar control. Researchers will also look at body composition (how much is muscle versus fat) using special measurement devices. They’ll track physical activity levels and strength to see if different diets affect how active people become. The study will also measure various blood compounds related to metabolism and inflammation, which are important for understanding overall health beyond just the number on the scale.

Previous research suggests that polyphenols—natural compounds in plants—may help with weight loss and heart health. However, most studies have looked at supplements or single foods, not compared eating whole plant-based foods versus taking supplements. This study fills that gap by directly comparing the two approaches. Earlier research also suggests that gut bacteria changes might explain some health benefits of plant-based diets, which is why this study will measure those changes in detail.

This study has several limitations to keep in mind. First, it only includes 99 people, which is a relatively small number, so results might not apply to everyone. Second, it only lasts 12 weeks, so researchers won’t know about long-term effects. Third, participants know they’re in a study (though researchers don’t know which group they’re in), which might change their behavior. Fourth, the study takes place in Chile with specific regional foods, so results might differ in other countries. Finally, this is just the research plan—actual results haven’t been collected yet, so we don’t know what the study will actually find.

The Bottom Line

Wait for the actual study results before making major dietary changes based on this research. Once results are published, they may suggest whether eating plant-based foods or taking supplements is more effective for weight loss and heart health. In the meantime, eating more plant-based foods like berries, apples, nuts, and olive oil is generally considered healthy by most nutrition experts, regardless of this study’s outcome. (Confidence: Moderate—based on existing general nutrition knowledge, not this specific study)

This research will be most relevant for adults aged 25-45 who are overweight or have obesity and want to improve their heart health. People interested in whether supplements can replace whole foods should pay attention to these results. Healthcare providers recommending weight loss strategies will also find this useful. However, people with normal weight or those without heart disease risk factors may find the results less directly applicable to their situation.

The study itself lasts 12 weeks, so researchers should have results within a few months of completing data collection. However, it typically takes 6-12 months after a study ends for results to be published in a scientific journal where the public can read them. Don’t expect to see major weight loss or health improvements overnight—the study measures changes over a 12-week period, and real-world results may take longer.

Want to Apply This Research?

  • Track daily intake of polyphenol-rich foods (berries, apples, nuts, olive oil, coffee, tea) by counting servings. Set a goal of 3-5 servings daily and log actual intake to see if you’re meeting targets. This mirrors what the study is measuring.
  • Start incorporating more plant-based foods into meals, especially the ones mentioned in the study: blueberries, apples, nuts, olive oil, and coffee. Try adding one new plant-based food to your diet each week rather than making drastic changes all at once.
  • Weekly weigh-ins combined with monthly measurements of waist circumference and energy levels. Track how you feel (energy, digestion, mood) alongside physical measurements, since the study measures both body changes and internal metabolic changes. Consider taking photos monthly to see body composition changes that the scale might not show.

This article describes a research study protocol (a plan for future research) and does not present completed results. The study has not yet been conducted, so no conclusions about effectiveness can be drawn at this time. This information is for educational purposes only and should not be used to make medical decisions. Before starting any new diet, supplement, or weight loss program, especially if you have existing health conditions or take medications, consult with your healthcare provider. The findings from this study, once completed, should be discussed with a doctor or registered dietitian to determine if they apply to your individual situation.