I put this theory to the test this past year. Weighing in at 169lbs (5’11”). I proceeded to lose 23 pounds over a 6 week period through simply managing portion size. I am a masters runner (44) and times for 5k and the mile at 169 lbs were 16:42 and 4:50. After losing weight, I ran 16:47 (much more difficult course than what I ran 16:42) and 4:49. So I can say that there was little if any difference in weight and performance.
At 2 sec per pound x 23 lbs, I should be running under 16.
Perhaps it has allowed me to stall the aging process, but I certainly did not improve significantly. I do feel better in general after cleaning up my diet and my training is more consistent. For the past 4 or 5 months I have been holding steady at 152lbs. (17lbs under my starting weight).
From my experience I would say “no” to this question, but maybe it would be different if I was 24 and not 44.