Obesity (BMI over 30) and those overweight (BMI 25-30) affects 46% of Americans over the age of 15 compared to 17% globally.
Obesity is associated with chronic low-grade inflammation, greater brain atrophy and white matter changes, disturbances in the blood-brain barrier, and an increased risk of Alzheimer's disease. In multiple sclerosis, obesity/overweight in childhood and adolescence is a risk factor for pediatric and adult-onset MS. This is true for both sexes but is more pronounced in females. (Lancet Neurol 2014;13(9);913-923)