It works to burn fat but it isn't ideal for maintaining lean mass while getting down to 4-5% BF for most of us. However, having Leucine alone every couple of hours during the fast could allow one to have the best of muscle retention AND fat burning. It might be worth a try.
The sheer food to eat in 3 squares is the hard sell. No one wants to average 1500kcals three times a day. You can either keep insulin quiet by eating protein and fats only for large portions of the day, while burning fat, or u can eat nothing for large portions and eat tons for short portions.
It's just a redistribution of metabolic intensions. Instead of several fat burning sessions and muscle building sessions per day, IF does it all in two sessions - fasting and feeding.
The real benefits of IF dieting is found in the insulin sensitivity benefits and immune system benefits. This alone should be the reason.