The 2001 Matthew McConaughey movie "Frailty" was a horror/murder mystery about an insane father and his tormented sons.

In real life, frailty is truly frightening — I mean physical frailty. It’s characterized by having at least three of the following symptoms: unintentional weight loss, exhaustion, weak grip strength, slow walking speed, and low physical activity levels.

It can lead to falls, disability, degraded quality of life, and even premature death. Frailty is clearly a condition you want to avoid.

Unfortunately, that’s hard to do if you're obese or have a large waist circumference in your 40s. Research published in BMJ Open looked at around 2,500 men and women starting about age 45, and followed them for 21 years. The people who were obese at the start were two and a half times more likely to become frail than healthy-weight folks.

And those with a large waist circumference were twice as likely to become frail or pre-frail (two of the symptoms of frailty) as people who started out with a low-risk waist size. In the U.S., that's 35.5 inches for men and 31.5 inches for women; these investigators used 37 inches for men, 31 for women.

If you're overweight or obese, there’s another reason to reshape yourself by following the steps to a younger, stronger, longer life in "The Great Age Reboot."