THURSDAY, June 25, 2020 (HealthDay News) -- If you've been looking for a good reason to slim down, consider this: Being obese at midlife appears to increase your odds for dementia.That's the takeaway from a large study just published by British researchers, and it echoes similar findings published in December.Dorina Cadar, lead researcher on the new study, said the goal is to identify risk factors that are influenced by lifestyle so steps can be taken to prevent mental decline. "We hope that a substantial portion, but admittedly not all, of dementia cases can be prevented through public health interventions," she said. Cadar is a senior research fellow at University College London. Her team found that people who are obese at midlife have a 31% higher risk for dementia than middle-aged people whose weight is normal -- and the risk is especially high for women. The good news: Losing weight may significantly lower the odds, the researchers said. For the study, Cadar and her colleagues analyzed data from nearly 6,600 people aged 50 and older who were part of a British study on aging. The researchers used three sources to ascertain dementia: doctor diagnosis, informant reports and hospital statistics.While obesity was a risk for both men and women, the risk of dementia was even higher for women with abdominal obesity -- a condition measured by their waist size. Over an average follow-up of 11 years, they were 39% more likely to develop dementia, the study found. This higher risk was independent of other factors, such as age, education, marital status, smoking, genetics, diabetes and high blood pressure. No association between abdominal obesity and dementia was found among men, the study authors said. But when the researchers considered both weight and waist size together, obese men and women alike had 28% higher odds of developing dementia. A study published in December of women only uncovered similar risks.Dr. Sam Gandy, associate director of the Mount Sinai Alzheimer's Disease Research Center in New York City, reviewed the new findings.