Some research suggests that a BMI of 23-30 may be associated with lower mortality risk in adults over 65, slightly higher than the standard 18.5-24.9 range. This 'obesity paradox' may be because modest extra weight provides reserves during illness.

Aging typically involves loss of muscle mass and bone density while fat mass increases. This means seniors can have a higher body fat percentage at the same BMI as younger adults, making BMI a less reliable indicator of health for this group.

For seniors, maintaining muscle mass, mobility, and functional fitness is generally more important than achieving a specific BMI number. Strength training, balance exercises, and adequate protein intake matter more than the scale reading.