When we talk about losing fat, what we are really doing is shrinking the adipose tissue, or fat cells. Think of a them as billions of microscopic balloons that can either shrink or expand based on our energy (caloric) balance. The only way to remove fat cells completely is through liposuction (which is not without its own danger), but the caveat is that if you go back to living and eating the same old way, the body is more than happy to create new fat cells to store that birthday cake! We are evolutionary programmed to be fat and happy, not lean and mean.
On to the topic of this post – I prefer dropping fat slowly for two reasons:
1) Functionality. It is absolutely possible to lose 7 pounds in 7 days (and I’ve come pretty darn close) but that doesn’t mean it’s the best option in every circumstance. Fasting is a physiological rest that requires physical rest as well as rest from mental or sensory stimulation. Now if you are working 30-40 hours or more a week, and your occupation requires any kind of minimum mental or physical performance (and I hope it does..?) then your brain need glucose (carbohydrates) to function. To maintain that hard-earned muscle mass, your skeletal muscles need glycogen (again, from carbohydrates) to get through those heavy workouts. Not to get too technical, but your body can convert fats to carbohydrates through a process called ketosis, but the switchover is not very rapid and you will feel sluggish.
2) Acclimating to your new body. The other reason I feel it’s important to lose fat slowly is because we need to psychologically “accept” our modified body composition. It sounds like a simple thing to overcome, but losing weight too rapidly can play serious mind games on you. Well-meaning family and friends will want to feed you donuts or perhaps Turron to fatten you up again. You will also find that your pants start falling at the waist and your dress shirts become super baggy. Then it’s time for your tailor to do more work! You may not yet feel “comfortable” in your new self and that may drive the urge to return to your old ways…
In short, I’m sticking to a 2 pound weight loss per week, which will come steadily, and can afford me a splurge meal here and there in the beginning if I’m too depleted and need to fill out again (a splurge meal for me at this point might be whole grains or starchier carbohydrates – that’s it). BUT the bottom line is as long as I’m losing 2 pounds a week then I’m on point, which is another reason to start your diet early.