What is the optimal rest between sets for fat loss?

Q: Is the optimal rest between sets for fat loss always 30 seconds, as you describe in your German Body Comp workouts?

A: Thirty seconds of rest is a general guideline; other variables may call for longer or shorter rest times. For example, the following fat-loss workout uses tri-sets with a combination of 10- and 90-second rest intervals.

 

A1) Close-grip bench presses, 4/0/1/0 tempo, 3 x 6

Rest 10 seconds

A2) 45 degree incline dumbbell

presses, 3/0/1/0 tempo, 3 x 12

Rest 10 seconds

A3) Decline low-pulley rope flyes, 2/0/1/0 tempo, 3 x 25

Rest 90 seconds

B1) Incline dumbbell hammer curls, 4/0/1/0 tempo, 3 x 6

Rest 10 seconds

B2) EZ-curl-bar close-grip

Scott curls, 3/0/1/0 tempo, 3 x 12

Rest 10 seconds

B3) Low-pulley supinated-grip curls, 2/0/1/0, 3 x 25

Rest 90 seconds

C1) Seated dumbbell presses, 4/0/1/0 tempo, 3 x 6

Rest 10 seconds

C2) Standing dumbbell lateral raises, 3/0/1/0 tempo,
3 x 12

Rest 10 seconds

C3) Low-pulley rope upright rows, 2/0/1/0 tempo, 3 x 25

Rest 90 seconds

Here is another fat-loss program. This one  uses 60-second rest intervals in some challenging multijoint exercises and giant sets:

 

A1) Barbell back squats, 3/2/1/0 tempo, 5 x 8-10

Rest 60 seconds

A2) Chinups, 3/0/1/2 tempo, 5 x 8-10

Rest 60 seconds

A3) Bent-knee deadlifts, 4/1/1/0 tempo, 5 x 8-10

Rest 60 seconds

A4) Barbell bench presses, 3/2/1/0 tempo, 5 x 8-10

Rest 60 seconds