Researchers looked at 38 different studies about eating berries and how they affect body weight and body composition. They found that people who ate berries or berry products had small but measurable decreases in body mass index (BMI) and body fat percentage. However, berries didn’t seem to change overall weight, waist size, or hip size much. While these results are encouraging, scientists say we need more high-quality studies to be sure about how helpful berries really are for weight management. The good news is that berries are healthy foods with other benefits, so eating them is a smart choice regardless.

The Quick Take

  • What they studied: Whether eating berries or berry products can help people reduce body fat and improve measurements like BMI (a measure of body weight relative to height) and body fat percentage.
  • Who participated: The analysis combined data from 38 different research studies involving people who ate berries or berry extracts as part of controlled experiments. The studies were randomized controlled trials, which is the gold standard for testing whether something actually works.
  • Key finding: People who ate berries had a small decrease in BMI (about 0.13 points lower) and body fat percentage (about 0.5% lower) compared to those who didn’t eat berries. These changes were statistically significant, meaning they’re unlikely to have happened by chance, though the actual amount of change is modest.
  • What it means for you: Eating berries may help slightly reduce body fat, but don’t expect dramatic weight loss. Berries work best as part of a healthy overall diet and lifestyle. They’re nutritious foods with many other health benefits, so eating them is a good idea even if weight loss is modest.

The Research Details

This was a meta-analysis, which means researchers searched through scientific databases to find all the high-quality studies about berries and body composition that had been published up to June 2024. They found 38 different studies that met their strict requirements—all of them were randomized controlled trials, which is the best type of study for testing whether something actually works. In these trials, some people were randomly assigned to eat berries while others didn’t, so researchers could fairly compare the two groups.

The researchers looked at 42 different intervention arms (different groups within studies) and combined all the data together to see if there was an overall pattern. They used statistical methods to combine results from studies of different sizes and designs, which gives a more complete picture than looking at any single study alone.

The berries studied included common types like blueberries, strawberries, raspberries, and cranberries, as well as berry extracts and powders. The studies varied in how long people ate berries (from a few weeks to several months) and how much they ate.

A meta-analysis is powerful because it combines information from many studies, which gives us a clearer answer than any single study could provide. By looking at 38 different studies together, researchers could see if the effects of berries were consistent across different populations, different types of berries, and different study lengths. This approach helps separate real effects from random variations or flukes.

The strength of this research comes from including only randomized controlled trials, which are considered the gold standard in nutrition science. However, the researchers noted that the overall amount of change in body measurements was small, and they called for more studies to be done. The fact that they registered their analysis plan beforehand (PROSPERO registration) is also a good sign of scientific rigor. One limitation is that the studies varied quite a bit in their methods, which can make it harder to draw firm conclusions.

What the Results Show

The analysis found three main positive results. First, people who ate berries had a small decrease in BMI of about 0.13 points. While this sounds tiny, it was statistically significant, meaning it’s unlikely to have happened by chance. Second, body fat percentage decreased by about 0.5% in people eating berries. Third, body fat mass (the actual amount of fat tissue in pounds or kilograms) decreased by about 0.67 units.

To put this in perspective, these are modest changes. For example, if someone weighed 200 pounds, a 0.13 decrease in BMI might translate to losing a few pounds of fat, not a dramatic transformation. However, the consistency of these findings across 38 different studies suggests that berries do have a real, measurable effect on body composition.

Interestingly, berries did NOT significantly change overall body weight, waist circumference, hip circumference, or the ratio of waist to hip size. This is an important finding because it suggests that berries may help reduce fat specifically while preserving muscle mass, which is actually a positive outcome.

The fact that berries reduced body fat but not overall weight is actually quite interesting. This suggests that when people eat berries, they may be losing fat tissue while maintaining or even gaining muscle tissue. Muscle weighs more than fat, so the scale might not move much even though body composition is improving. This is generally considered a better outcome than just losing weight overall. The lack of change in waist and hip circumference suggests that berries don’t target fat loss in specific areas of the body.

Previous research has shown that berries have many health benefits, including protecting heart health and reducing inflammation in the body. This new analysis adds to that evidence by showing that berries may also help with body composition. However, the effects are modest compared to what you’d see with major dietary changes or exercise. Berries appear to work best as part of a comprehensive healthy lifestyle rather than as a standalone weight loss solution.

The researchers were honest about several limitations. First, while 38 studies is a good number, the total amount of change observed was small, so we need to be cautious about how much impact berries will have for any individual person. Second, the studies varied in important ways—different types of berries, different amounts eaten, different study lengths, and different types of people studied. This variation makes it harder to say exactly how much berries will help any particular person. Third, the researchers noted that more well-designed studies are needed to be confident in these findings. Finally, we don’t know if the benefits come from eating whole berries or if berry extracts and powders work just as well.

The Bottom Line

Based on this research, eating berries as part of a healthy diet may help slightly reduce body fat and BMI. However, don’t expect major weight loss from berries alone. The evidence suggests a modest benefit (confidence level: moderate). Berries are nutritious foods rich in vitamins, fiber, and antioxidants, so eating them is a good idea for overall health regardless of weight management. Aim to include berries regularly in your diet as part of a balanced eating pattern that includes whole grains, lean proteins, vegetables, and healthy fats.

Anyone interested in improving body composition and reducing body fat should know about this research. It’s especially relevant for people looking for natural foods that might support their health goals. However, this research is NOT a substitute for medical advice if you have obesity, diabetes, or other health conditions—talk to your doctor or a registered dietitian for personalized guidance. People with berry allergies should obviously avoid berries. The findings apply to generally healthy adults; we don’t know if the same effects occur in children, pregnant women, or people with certain medical conditions.

Based on the studies reviewed, most showed changes over weeks to months of eating berries regularly. You shouldn’t expect to see results in just a few days. Plan to eat berries consistently for at least several weeks to a few months to potentially see measurable changes in body composition. Remember that the changes are modest, so you might not notice dramatic differences in how you look or feel, but measurements like BMI and body fat percentage might improve slightly.

Want to Apply This Research?

  • Track daily berry consumption (type and amount in grams or cups) and measure body fat percentage monthly using a scale or other method. Record this alongside overall diet quality to see if berries correlate with improvements in body composition over time.
  • Set a specific goal like ’eat one serving of berries daily’ and use the app to log which berries you eat and when. Create reminders to add berries to breakfast, snacks, or smoothies. Track your consistency over weeks and months rather than expecting immediate results.
  • Monitor body composition metrics (BMI and body fat percentage) monthly rather than weekly, since changes are modest and gradual. Also track overall diet quality and physical activity to understand the full picture of what’s affecting your body composition. Use the app to identify patterns—for example, do months when you eat more berries show better body composition results?

This research summary is for educational purposes only and should not be considered medical advice. While this meta-analysis suggests berries may have modest effects on body composition, individual results vary significantly. If you have obesity, diabetes, heart disease, or are taking medications, consult with your doctor or a registered dietitian before making major dietary changes. Berries are generally safe for most people, but some individuals may have allergies or sensitivities. This research shows correlation and modest association, not definitive proof of weight loss. Sustainable weight management requires a comprehensive approach including balanced nutrition, physical activity, and lifestyle changes—berries are one small piece of a larger puzzle.