Should you swiftly or gradually cut calories at the beginning of a diet? Swiftly.
Should you swiftly or gradually cut calories towards the middle or end of a diet? Gradually.
I blogged about metabolic adaptation and buffer zones here. Read that first.
Now, let me illustrate with my own experience.
Transitioning from a lean mass gaining phase—where I am able to maintain weight on ~4,000 kcals/day—to a fat loss phase, I have tried 2 approaches to decreasing calorie intake:
Decreasing calories gradually by ~200-300 kcals/day per week (with the hopes that I would be able to lose body fat while eating more)
Decreasing calories more swiftly by ~500-600 kcals/day per week
Disappointingly, the first approach (decreasing calories gradually) usually leads to no significant fat loss the first couple weeks; bodyweight also does not really budge. Since my calorie intake is still in the buffer zone, metabolism rapidly adapts to relatively small adjustments in calorie intake.
With the second approach, I can achieve a significant amount of fat loss the first couple weeks (about 5-10 lbs of body weight loss). Despite my calorie intake still falling in the buffer zone, I can sort of capitalize on the opportunity with the precondition that the calorie adjustments are large enough. A caveat is that approach two works better if you know—from prior experience—what your buffer zone calorie intake is. Otherwise, you risk overshooting the decreases in calorie intake, ending up eating less than you would need to for fat loss.
Now, once you are dieting near the lower threshold of your buffer range, that is when smaller adjustments/decreases in calorie intake are better options if fat loss stalls. While your TEE may still drop (e.g. from further decreases in body weight and the inevitable loss in LBM), it won’t be as significant. Decreases in calorie intake of ~100-200 kcals/day per week if fat loss stalls are appropriate.
Throughout my first couple years working with coaches and asking about why the phenomenon I described above happens, the common response was something along the lines of “it takes a while to get the ball rolling” or “you need to build momentum.” This never made sense to me. Like they just pulled these answers out of their asses. Nope. What I described above is what is happening.