Saturday, January 29, 2011
There’s a relatively new diet out there called calorie restriction, or CR. Followers would argue though that it is not a diet, it is a “lifestyle”. They claim that reducing their daily caloric intake by 30% to as much as 50% is the fountain of youth, and there are studies showing they may increase their life span by as much as 40%. They brag of lowered blood pressure, blood sugar and heart rate. They claim that they get to a point that they really aren’t hungry any more. This seems difficult to believe when being hungry all the time is the #1 reason people fail at even conservative 15-20% under maintenance diets. Neuroendocrine profiles clearly show that animals under CR are continuously hungry. At what point do these benefits become perilous? Sure, low blood pressure is good, but to a point- past which it is labeled hypotension. At this level it can be a nuisance causing dizziness upon standing and fainting spells. Further on down the road it can deprive the brain and other organs of vital oxygen. Same goes for lowered blood glucose. If it remains too low for too long there is a condition called neuroglycopenia that can result. Basically, the brain suffers from too little fuel for too long and there is fatigue, slurred speech, ataxia (incoordination), blurred vision and confusion.
A 20 year study was recently completed and published in Science News Magazine. There is compelling evidence that CR improves the health and extends the life spans of every tested species. “Tested species” however includes worms, spiders, rodents, dogs, cows, and monkeys. This study looked specifically at rhesus monkeys. We are only recently starting to do in-depth research on human subjects. There are now enough human guinea pigs out there following this diet, er, way of life that we have some to track. Researchers believe “it is likely we will see similar results in humans”.
Much more well studied are the effects of anorexia nervosa. Much scarier are the similarities between CR and anorexia. The physical effects of CR include:
- Decreased RMR (resting metabolic rate)
- Loss of LBM (lean body mass)
- Loss of bone mass
- Decreased heart rate (bradycardia)
- Decreased blood pressure (hypotension)
- Decreased cardiac muscle mass
- Food related obsessions
Other deleterious health effects of a persistent caloric deficit are low BMI and the effects of starvation. BMI under 18 is associated with significantly increased mortality from non-cancer, non-cardiovascular disease causes. In a nut shell, you are at a hugely increased risk of dying from just about anything- except cancer or heart disease. Nice. Severe calorie restriction may also lead to low-grade, insidious starvation effects on the body. In absence of adequate intake, the body turns to muscle, collagen, bone and remaining fat stores for fuel. Catabolic (muscle wasting) hormones such as cortisol are elevated, and catabolic (muscle sparing) hormones such as insulin decline. With too few calories, essential nutrient intake suffers as well, especially fat-soluble vitamins. These require fat for proper absorption. High calorie foods such as meat, nuts, dairy and oils are omitted due to their high caloric density.
Interestingly, every single one of these “effects” are also effects of Anorexia nervosa, but believers don’t want you to acknowledge that. Is this lifestyle a wolf in sheep’s clothing? Might these people already be the same people who would be more apt to fall into disordered eating behavior? Sometime back I saw two proponents of the diet, a husband and wife, on Oprah. Something about their demeanor bothered me. It wasn’t just that they were staunchly defensive of their “lifestyle”, but that more that they had no sparkle in their eyes. Oprah followed them through a typical days’ eating. They loaded up huge (I mean HUGE) salad bowls with greens, greens and more greens explaining that all those leaves only amount to about 30 calories. Then they topped off that massive mound with finely measured bits of more calorie dense items such as sunflower seeds and protein. Dressing was too “costly” calorie wise, so simple vinegar or lemon juice would have to do.
It seemed as though the rigid structure and deprivation of their daily existence had stolen something from their souls, they were more like automatons. Studies are showing that the later in life you start the CR lifestyle, the less the benefits. In other words, you have to starve for most of your life to reap the full benefits. Even more recently they say the life extending benefits may only be an added 2% to your life span, not the lofty 40% they originally claimed. Personally, I’m not signing up for complete and utter misery every single day for the rest of my life- to possibly add ONE year to it. Would you like a splash of lemon on those greens?