For 55-year old Dan Collins, fencing keeps his muscles tight, his body trim, and his eating habits on point.
But he hasn't always been fit.
"I was the fat kid, last kid picked for dodgeball when I was in elementary school," he recalled.
By the time he graduated college, Collins weighed 239 pounds.
For Collins, it was the pressure of weekly weigh-ins that started him in the right direction.
"I had the fear of the white lab coat. A doctor going to be peering over my shoulder, moving the little scale thing along and me worried about, did I lose anything? Did I gain anything?"
Dr. Marc Leavey, who has worked with obese patients throughout his 40-year career, is a big believer in positive peer pressure, or the diet buddy system.
"If I can get a husband and wife to diet together, exercise together, it's almost always more effective," said Leavey, with Mercy Medical Center in Baltimore.
Studies from Brown medical school and Dartmouth College show partnering with someone who is serious about slimming down increases your chances.
If you feel tempted to cheat, phone or text a friend for support. Delay the treat for 15 minutes. You may erase the craving.
Leavey also suggests weight-loss partners help each other stick to the numbers needed to drop weight. To lose a pound a week, cut back by 500 calories a day and increase exercise to burn 500 additional calories.
For Collins, having his doctor hold him accountable has worked. His blood pressure is normal, down from a high of 150 over 90. And he has maintained a 60-pound weight loss for 30 years.
"I've changed my relationship with food," he said. "And now we get along together a lot better."