>he asserted that eating wasn’t the problem, it was laying around on our asses.
Yep.
IMO, resistance training is essential in any fat loss plan. Out of shape slobs (me) and/or those new to lifting can usually gain some muscle while losing fat. At the very least lifting helps preserve muscle. If you eat a hypocaloric diet and don’t exercise, expect to lose 50/50 fat and muscle.
The more muscle you have, the more you get to eat without getting fatter. What a deal! Figures I’ve seen vary from a low of about 30 kcal/day per additional pound of muscle up to about 60 kcal. I suspect the lower number is closer to the truth. Adding 10 lbs. of muscle increases your maintenance Calories by at least 300 per day. That’s nothing to sneeze at. Those extra 10 lbs. will burn 109,500 kcal in a year, the same as burning roughly 31 lbs. of fat.
Speaking of exercise for losing fat, anyone interested in cardio workouts should do a Google search on HIIT. It works very well.