Calorie Restriction Transition


Hopefully you have been favorably impressed by what you have heard and read about calorie restriction. You may have even decided that this is what you want to do for the balance of your life. But you are not sure where or how to start. Here are a two critical points that can make the difference between health and disaster:

  1. Adopt calorie restriction gradually. Animal studies clearly show that an abrupt commencement of a calorie restriction diet actually reduces rather than enlarges life span. This makes complete sense if you think about it. Calorie Restriction produces a condition in your body that does not occur over night. We know that when calorie restricted, you body becomes much more efficient. Your body temperature drops 1-4 degrees; Your heart rate slows; Your blood pressure drops; Numerous other body functions adapt to the new caloric environment. Your body cannot accomplish changes, adaptations such as these overnight. 

Have you ever known or read of someone who has climbed Mount Everest? Often people wonder why a expedition like that is a 2-3 month event when the actual climbing itself is a 3-4 day event. The answer lies in the physiological adaptation required of the body to survive at altitudes above 21,000 feet. It is a wondrous commentary on the body’s capacity to adapt that it can learn to survive on 33% of the oxygen that it would otherwise require. But this adaptation is not instant. In fact if a climber were to skip the acclimatization phase of his climb, he would be dead long before reaching the summit. Put differently, if a climber were simply deposited on the summit of Mt. Everest, he would be dead within minutes.

Your body’s adaptation to calorie restriction is similar to acclimatization. The body is willing and capable of adapting to new, more challenging conditions so long as it is given the opportunity to do so at the pace it requires. While there is no firm rule here and the animal studies may require some adjustment for our purposes, there are some general rules that those of us doing calorie restriction have followed. Most of us have followed the advice of Dr. Roy Walford, an early CR leader and scientific authority (incidentally, I highly recommend his book, “The 120 Year Diet”) which suggests an adaptation period of 6-12 months. This means that you should  titrate your calorie restriction so that you arrive at your eventual restriction goal (for example, a 25% reduction in daily calories consumed) at the appropriate point in the future (for example, 6 months later). A good indicator for those who are significantly overweight at the start is the rate of weight loss. Your weight loss should parallel your calorie restriction. In other words, the loss should be dispersed evenly over the adaptation period. Resist the temptation to shed weight rapidly. This is the tactic of commercial diet schemes whose horizons are measured in days and weeks. Calorie restriction is permanent; its about the rest of your life. That is all the more reason to do this right. Be patient.

  1. Determine your particular set point before you start restricting your calories. When starting calorie restriction, people are tempted to plunge forward before getting a point of reference regarding their pre-CR calorie consumption. This requires some explanation: Calorie restriction, as it relates to longevity and health, refers to reductions in calories below an organism’s particular “set point”. The “set point” is the number of calories that the organism (you, for example) would choose to consume if eating entirely without inhibition. In other words, how many calories would your body request each day if given its unfettered preference (i.e. while neither dieting nor gorging)? 

    Each of us has a metabolism which is designed or conditioned to operate at a certain level. Some of us have very active metabolisms that prod us to eat more than those whose metabolisms are much slower. As a result, some of us gain weight more easily than others. Appetite, however, is more complicated and involves additional factors that no one fully understands. What we do know is that set points are very individual, as are their corresponding body weights. This is why you cannot identify a calorie restriction practitioner by his body weight. While it’s generally true that CR practitioners are very lean (my BMI is 18), it’s not necessarily true.  Think about it: If you are 5’8” and weigh 250 lbs. before CR (which we will assume reflects your set point calorie consumption), after a 30% calorie restriction your weight might settle in the 175 lbs. range. That’s not exactly lean. One can argue, of course, that there is room for further restriction in such circumstances, that you should reduce you calories even more. Perhaps that’s true. But the scientific research suggests that the chunky calorie restrictor in my example should indeed experience some, if not all, of the benefits enjoyed by his leaner 30% restricting counterpart.

Therefore, begin your calorie restricted life by eating without restriction. Do this for      four to five days while carefully counting your calories. Use these figures to calculate your daily average, which will constitute your set point.