"We have a group Facebook page where people are sharing what they are doing and giving tips to others," Mr Hooks said.
"A lot of our staff are really excited about it and some people are getting together to exercise. For the winners it's really worth it because there are cash prizes from the entry fee, plus money that Alarm Watch is putting in.
"There's a really good relationship between staff members and a lot of support from everyone competing for everyone else. Even though we are all working different shifts, we have the right kind of workplace rapport for it."
Staff from across the company are involved, from the general manager and technical manager to monitoring operators. Ages range from early 20s to early 50s with more women than men participating.
Mr Hooks won the Alarm Watch biggest loser competition in 2014 when he was working in the company's Auckland satellite office while studying at university.
"That time I did it almost solely by exercise because I was on a meal plan where I was living so there weren't choices," he said.
"This time I'm doing more of a balance of a better diet and exercise as they work well together. In 2014 the competition was a really big motivator for me and when it was suggested we do another one I remembered how helpful it was for me."
Alarm Watch staff hope their efforts may inspire other Whanganui businesses to run similar events.
