Combining Diet and Exercise Most Effective for Preventing Abdominal Fat Gain, Study Finds

Improving diet and increasing physical activity levels together may be more effective at preventing weight gain-particularly harmful fat inside the abdomen-than just changing one of these behaviors, new research from the University of Cambridge suggests.

An analysis of changes in physical activity and diet quality in UK adults found that while improved diet quality and increased physical activity were each independently associated with lower increases in body fat, the greatest benefits were achieved by combining both.

Body fat is stored in different locations, some of which are more harmful than others. Subcutaneous fat is stored under the skin and can be considered relatively healthy. In contrast, visceral fat stored around the organs in the abdomen is linked to a higher risk of diseases such as type 2 diabetes, fatty liver disease, and heart disease.

In a study published in JAMA Network Open, researchers from the Medical Research Council (MRC) Epidemiology Unit at the University of Cambridge followed 7,256 adults from the Fenland Study over seven years.

The mean age of the study participants was 49 years at baseline, and 56 years at follow-up. At baseline, and again after an average of around seven years, the researchers measured Fenland study participants’ physical activity energy expenditure for at least 72 hours using wearable heart rate and movement sensors.

The researchers also assessed participants’ diet quality by the degree of adherence to the Mediterranean diet pattern using a food frequency questionnaire. the Mediterranean diet focuses on eating fruits, vegetables, whole grains, legumes, nuts, and olive oil, with moderate amounts of fish, poultry, eggs, and dairy, while limiting consumption of red meat and sweets.

Small Dietary & Exercise Improvements Linked to Reduced Abdominal Fat

A new study published in JAMA Network Open suggests that even modest improvements in diet and physical activity, when made concurrently, are associated with reductions in adiposity – a measure of body fat – particularly abdominal fat. Researchers found that adults who simultaneously improved both their diet quality and physical activity levels experienced more favorable changes in body composition than those who focused on only one behavior.

The study analyzed data from a large cohort of adults, tracking changes in their dietary habits, physical activity, and body composition over time.Diet quality was assessed using a validated dietary score,while physical activity was measured through self-reported questionnaires. Adiposity was persistent using measures like waist circumference and body mass index (BMI).

The findings indicate that the combined effect of dietary improvement and increased physical activity was greater than the sum of their individual effects. This suggests a synergistic relationship, where the benefits of a healthier diet are amplified when combined with regular exercise, and vice versa. Specifically, the research team observed that participants who increased their intake of nutrient-rich foods and increased their physical activity experienced the most meaningful reductions in abdominal fat, a type of fat strongly linked to metabolic diseases like type 2 diabetes and heart disease.

“Our research highlights the importance of a holistic approach to weight management,” said lead author Dr. seyed Aryannezhad. “Focusing on both diet and exercise, rather than just one or the other, appears to be the most effective strategy for reducing harmful body fat and improving overall health.”

The study underscores that considerable changes aren’t necessarily required to see benefits. even small, enduring improvements in both diet and physical activity can contribute to meaningful reductions in adiposity and potentially lower the risk of chronic diseases.

More information:

Aryannezhad, S et al. Concurrent Changes in Diet Quality and Physical Activity and Association With Adiposity in Adults,JAMA Network Open (2025). DOI: 10.1001/jamanetworkopen.2025.45232