If you’ve ever wondered whether eating healthy or exercising more is better for staying slim, new research has an answer: doing both together is more powerful than doing either alone. A large 7-year study of British adults shows that combining a healthier diet with regular physical activity does more than just help you lose weight — it can also reduce dangerous fat stored deep in your body and lower your risk of chronic disease.
What the Study Found
Published on November 21, 2025, in JAMA Network Open, the study followed almost 7,300 adults in the UK, tracking their diet habits, physical activity, and body fat levels over seven years. Participants were an average of 49 years old when the study began.
Researchers looked closely at where people gained or lost fat — not just how much they weighed.
According to lead author Dr. Shayan Aryannezhad, who conducted the research at the University of Cambridge, “Not all fat is the same. Fat stored around the organs — known as visceral fat — is the most harmful and is linked to serious conditions like heart disease, fatty liver, and type 2 diabetes.”
Key Results:
| Group | Weight Gain Over 7 Years | Visceral Fat Change |
|---|---|---|
| No change in diet or activity | Baseline | Baseline |
| Improved diet only | Slightly less | Slightly less |
| Increased activity only | Slightly less | Slightly less |
| Improved both diet and activity | 4 pounds less | 150g (5 oz) less |
So, while either a better diet or more exercise helped a little, combining the two had a much bigger impact — especially on harmful fat around the organs.
Why Visceral Fat Matters
Visceral fat is stored deep inside the abdomen, surrounding vital organs like the liver, pancreas, and intestines. Unlike the fat you can pinch under your skin, this type of fat:
- Increases inflammation
- Disrupts hormone function
- Raises risk of heart disease, diabetes, and metabolic syndrome
Losing visceral fat isn’t just about looking slimmer — it’s about preventing long-term health problems.
What Makes the Diet-Exercise Combo So Effective?
The study suggests that:
- Healthy eating, especially following a Mediterranean-style diet, helps manage calorie intake and supports nutrient balance.
- Regular physical activity boosts energy expenditure and improves how the body uses fat for fuel.
- Together, they create a sustainable pattern that reduces overall fat and targets visceral fat more effectively.
Small Changes, Big Results
You don’t have to become a gym rat or give up all your favourite foods. The study highlights that even small, consistent improvements in both diet and exercise can lead to significant long-term benefits.
According to Dr. Nita Forouhi, senior author of the study and programme leader at the MRC Epidemiology Unit, “Despite the challenges of living in environments that promote unhealthy eating and inactivity, there is benefit from making small, sustained changes.”
Simple Ways to Start:
- Walk briskly for 30 minutes daily
- Follow a Mediterranean-style diet: more fruits, vegetables, whole grains, healthy fats (like olive oil), and lean proteins
- Cut back on processed foods, sugary drinks, and red meats
- Track progress and stay consistent
