Diet or exercise — which actually works best for weight loss?A new study says the real power comes from doing both.Researchers found improving diet and increasing physical activity at the same time led to a sizeable reduction in body fat, especially the harmful visceral or belly fat that surrounds organs and is linked to type 2 diabetes, fatty liver disease, and heart disease.The researchers followed more than 7,000 adults for seven years, tracking their activity with wearable sensors and scoring their diets based on how closely they matched a Mediterranean-style pattern... more plant-based foods, whole grains, beans and healthy fats… fewer sweets and red meat.The results: people who improved both habits saw the biggest reductions in body fat. Changing just one led to only modest shifts.Those who upgraded diet and activity together gained about 4 pounds less total body fat over time and 16% less visceral fat.The lead author says, “Combining a better diet with more physical activity is an effective way to improve not just weight, but how much and where fat is stored in the body.”Researchers say the findings underscore the need for healthier food environments and more accessible, affordable options for physical activity.Source: JAMA Network OpenAuthor Affiliations: University of Cambridge .Sign up for our weekly HealthDay newsletter