In 1990, while I was in the Navy and in Naples, Italy, I was station manager of the Armed Forces Radio and Televsion Service affiliate there.
One day, a guy I had seen around the base came into the station to see if he could advertise his services as a personal trainer on TV and radio. He was an Army reservist whose wife was active-duty Army at the NATO base. It also turned out he was a special forces officer, and he had been certified for dietary/nutrition services as well as had experience as a personal trainer. He had received all necessary base approval to work in the base gym.
It turns out several of us in the station signed up with him. I went from 235 pounds to 189 pounds in two months, working on a 3-day-a-week Nautilus circuit at the base gym, which included stationary bicycle for 30 minutes at the end of each workout. I modified my diet which was carb-based. Lots of vegetables, lean white meats, pasta and potatoes, but no beef, oils, butters or sugars.
That kind of diet works when combined with several days of intense working out, but not for every day use.
After that loss, Mike (personal trainer) moved me to free weights where the fun began (not). I stabilized at 195 (which was ideal for me) and stayed there for many years.
And that's ALL I'm sayin'!