All factors

Obesity

Obesity at age 50 nearly doubles dementia risk. Weight loss in the years just before diagnosis is a sign of the disease, not protection.

Population risk0.7%
Evidence gradeCohort study

A large group of people followed for years or decades. Shows a real-world link, though not proof of cause by itself.

Why it matters

Even modest weight loss (5-10%) reduces inflammation and improves blood sugar control, both of which protect the brain.

What to ask at the checkup

Ask whether a weight management plan would be appropriate

Screening: BMI calculation

Sources

Obesity trajectories and risk of dementia: 28 years of follow-up in the Whitehall II Study

Singh-Manoux A, Dugravot A, Shipley M et al.. Alzheimer's & Dementia, 2018.

Being obese at 50 almost doubled the chance of dementia decades later. The weight loss some people show near diagnosis is the disease itself, not a good sign.

Dementia prevention, intervention, and care: 2024 report of the Lancet standing Commission

Livingston G, Huntley J, Liu KY et al.. The Lancet, 2024.

Fourteen things people can change account for nearly half of dementia cases at the population level.

Routines for this factor

Step on the scale this week

Weigh in once this week and record the number.

2 min, difficulty 1/3

Take the stairs once today

Choose stairs over the elevator or escalator for one trip.

2 min, difficulty 2/3

This is research information, not medical advice. Nothing here replaces your parent's doctor.