Overview

• Penn State–led researchers analyzed 2011–2021 data from 4,304 adults aged 65+ and found that greater year-to-year variability in weight, BMI, or waist size tracked with steeper declines in memory, orientation, and executive function.
• Participants with the highest variability experienced roughly two to four times the cognitive decline compared with those with the most stable measurements.
• Losing at least 5% of body weight or cycling between losses and gains of that magnitude was associated with faster decline, while weight gain showed a trajectory similar to stable weight.
• The study, published in Obesity, is observational and cannot prove causation, and the authors note limits including predominantly White participants and incomplete data on intentional versus unintentional weight loss.
• The researchers recommend consistent home weighing under the same conditions and notifying physicians if weight is not stable.